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Wojan F, Stray-Gundersen S, Zhao J, Lalande S. Impaired erythropoietin response to hypoxia in type 2 diabetes. Acta Diabetol 2024; 61:925-932. [PMID: 38570345 DOI: 10.1007/s00592-024-02269-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 03/03/2024] [Indexed: 04/05/2024]
Abstract
AIMS Patients with type 2 diabetes have a 20% lower total blood volume than age- and weight-matched healthy adults, suggesting a reduced capacity to transport oxygen in this population. Intermittent hypoxia, consisting of alternating short bouts of breathing hypoxic and normoxic air, increases erythropoietin levels, the hormone regulating red blood cell production, in young and older adults. The objective of this study was to determine the effect of a single session of intermittent hypoxia on erythropoietin levels and hemoglobin mass, the absolute mass of hemoglobin contained in red blood cells, in patients with type 2 diabetes. METHODS Ten patients with type 2 diabetes were exposed to an intermittent hypoxia protocol consisting of eight 4-min cycles at a targeted oxygen saturation of 80% interspersed with normoxic cycles to resaturation. Erythropoietin and hemoglobin mass responses to intermittent hypoxia in patients with type 2 diabetes were compared to previously published data from an identical intermittent hypoxia protocol performed in age-matched older adults. RESULTS Intermittent hypoxia increased erythropoietin levels in older adults but did not induce any change in erythropoietin levels in patients with type 2 diabetes (3.2 ± 2.2 vs. 0.2 ± 2.7 mU/ml, p = 0.01). Hemoglobin mass indexed to body weight was 21% lower in patients with type 2 diabetes than in older adults (8.1 ± 1.7 vs. 10.2 ± 2.1 g/kg, p < 0.01). CONCLUSIONS These findings suggest an impaired erythropoietin response to decreased oxygen levels in patients with type 2 diabetes, which may contribute to the reduced oxygen transport capacity observed in this population.
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Affiliation(s)
- Frank Wojan
- Department of Kinesiology and Heath Education, The University of Texas at Austin, Austin, TX, USA
| | - Sten Stray-Gundersen
- Department of Kinesiology and Heath Education, The University of Texas at Austin, Austin, TX, USA
| | - Jiahui Zhao
- Department of Kinesiology and Heath Education, The University of Texas at Austin, Austin, TX, USA
| | - Sophie Lalande
- Department of Kinesiology and Heath Education, The University of Texas at Austin, Austin, TX, USA.
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2
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Macedo ACPD, Schaan CW, Bock PM, Pinto MBD, Botton CE, Umpierre D, Schaan BD. Cardiorespiratory fitness in individuals with type 2 diabetes mellitus: a systematic review and meta-analysis. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2023; 67:e230040. [PMID: 37738467 PMCID: PMC10665050 DOI: 10.20945/2359-4292-2023-0040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 05/30/2023] [Indexed: 09/24/2023]
Abstract
Objective To conduct a systematic review and meta-analysis assessing the cardiorespiratory fitness (CRF) among individuals with and without type 2 diabetes. Materials and methods The current review was registered in PROSPERO under the number CRD42018082718. MEDLINE, EMBASE, and Cochrane Library databases were searched from inception through February 2022. Eligibility criteria consisted of observational or interventional studies that evaluated CRF through cardiopulmonary exercise testing or six-minute walk test in individuals with type 2 diabetes compared with individuals without type 2 diabetes. For data extraction, we used baseline CRF assessments of randomized clinical trials or follow-up CRF assessments in observational studies. We performed a meta-analysis using maximal oxygen consumption (VO2 max), and distance walked in the 6MWT as primary outcomes. They were extracted and expressed as mean differences (MDs) and 95% CIs between treatment and comparator groups. The meta-analysis was conducted using Review Manager (RevMan) software. Results Out of 8,347 studies retrieved, 77 were included. Compared with individuals without type 2 diabetes, individuals with diabetes achieved a lower VO2 max (-5.84 mL.kg-1.min-1, 95% CI -6.93, -4.76 mL.kg-1.min-1, p = <0.0001; I2 = 91%, p for heterogeneity < 0.0001), and a smaller distance walked in 6MWT (-93.30 meters, 95% CI -141.2, -45.4 meters, p > 0.0001; I2: 94%, p for heterogeneity < 0.0001). Conclusion Type 2 diabetes was associated with lower cardiorespiratory fitness, as observed by lower VO2 max on maximal tests, and smaller distance walked in 6MWT, however the quality of studies was low.
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Affiliation(s)
- Aline Chagastelles Pinto de Macedo
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduaçÃo em Ciências Médicas: Endocrinologia, Porto Alegre, RS, Brasil
- Laboratório de Atividade Física, Diabetes e Doença Cardiovascular (LADD), Centro de Pesquisa Clínica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
| | - Camila Wohlgemuth Schaan
- Laboratório de Atividade Física, Diabetes e Doença Cardiovascular (LADD), Centro de Pesquisa Clínica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
| | - Patricia Martins Bock
- Laboratório de Atividade Física, Diabetes e Doença Cardiovascular (LADD), Centro de Pesquisa Clínica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil,
- Faculdades Integradas de Taquara, Taquara, RS, Brasil
- Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Mariana Brutto de Pinto
- Laboratório de Atividade Física, Diabetes e Doença Cardiovascular (LADD), Centro de Pesquisa Clínica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
| | - Cintia Ehlers Botton
- Instituto de AvaliaçÃo de Tecnologia em Saúde (IATS) - CNPq/Brasil, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
- Universidade Federal do Ceará, Instituto de EducaçÃo Física e Esportes, Fortaleza, CE, Brasil
- Programa de Mestrado em Fisioterapia e Funcionalidade, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - Daniel Umpierre
- Laboratório de Atividade Física, Diabetes e Doença Cardiovascular (LADD), Centro de Pesquisa Clínica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
- Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
- Instituto de AvaliaçÃo de Tecnologia em Saúde (IATS) - CNPq/Brasil, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
| | - Beatriz D Schaan
- Universidade Federal do Rio Grande do Sul, Programa de Pós-graduaçÃo em Ciências Médicas: Endocrinologia, Porto Alegre, RS, Brasil
- Laboratório de Atividade Física, Diabetes e Doença Cardiovascular (LADD), Centro de Pesquisa Clínica, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
- Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
- Instituto de AvaliaçÃo de Tecnologia em Saúde (IATS) - CNPq/Brasil, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brasil
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3
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Butenas ALE, Copp SW, Hageman KS, Poole DC, Musch TI. Effects of comorbid type II diabetes mellitus and heart failure on rat hindlimb and respiratory muscle blood flow during treadmill exercise. J Appl Physiol (1985) 2023; 134:846-857. [PMID: 36825642 PMCID: PMC10042612 DOI: 10.1152/japplphysiol.00770.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/10/2023] [Accepted: 02/17/2023] [Indexed: 02/25/2023] Open
Abstract
In rats with type II diabetes mellitus (T2DM) compared with nondiabetic healthy controls, muscle blood flow (Q̇m) to primarily glycolytic hindlimb muscles and the diaphragm muscle are elevated during submaximal treadmill running consequent to lower skeletal muscle mass, a finding that held even when muscle mass was normalized to body mass. In rats with heart failure with reduced ejection fraction (HF-rEF) compared with healthy controls, hindlimb Q̇m was lower, whereas diaphragm Q̇m is elevated during submaximal treadmill running. Importantly, T2DM is the most common comorbidity present in patients with HF-rEF, but the effect of concurrent T2DM and HF-rEF on limb and respiratory Q̇m during exercise is unknown. We hypothesized that during treadmill running (20 m·min-1; 10% incline), hindlimb and diaphragm Q̇m would be higher in T2DM Goto-Kakizaki rats with HF-rEF (i.e., HF-rEF + T2DM) compared with nondiabetic Wistar rats with HF-rEF. Ejection fractions were not different between groups (HF-rEF: 30 ± 5; HF-rEF + T2DM: 28 ± 8%; P = 0.617), whereas blood glucose was higher in HF-rEF + T2DM (209 ± 150 mg/dL) compared with HF-rEF rats (113 ± 28 mg/dL; P = 0.040). Hindlimb muscle mass normalized to body mass was lower in rats with HF-rEF + T2DM (36.3 ± 1.6 mg/g) than in nondiabetic HF-rEF counterparts (40.3 ± 2.7 mg/g; P < 0.001). During exercise, Q̇m was elevated in rats with HF-rEF + T2DM compared with nondiabetic counterparts to the hindlimb (HF-rEF: 100 ± 28; HF-rEF + T2DM: 139 ± 23 mL·min-1·100 g-1; P < 0.001) and diaphragm (HF-rEF: 177 ± 66; HF-rEF + T2DM: 215 ± 93 mL·min-1·100g-1; P = 0.035). These data suggest that the pathophysiological consequences of T2DM on hindlimb and diaphragm Q̇m during treadmill running in the GK rat persist even in the presence of HF-rEF.NEW & NOTEWORTHY Herein, we demonstrate that rats comorbid with heart failure with reduced ejection fraction (HF-rEF) and type II diabetes mellitus (T2DM) have a higher hindlimb and respiratory muscle blood flow during submaximal treadmill running (20 m·min-1; 10% incline) compared with nondiabetic HF-rEF counterparts. These data may carry important clinical implications for roughly half of all patients with HF-rEF who present with T2DM.
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Affiliation(s)
- Alec L E Butenas
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
| | - Steven W Copp
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
| | - K Sue Hageman
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas, United States
| | - David C Poole
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas, United States
| | - Timothy I Musch
- Department of Kinesiology, Kansas State University, Manhattan, Kansas, United States
- Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas, United States
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4
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Le Corre A, Caron N, Turpin NA, Dalleau G. Mechanisms underlying altered neuromuscular function in people with DPN. Eur J Appl Physiol 2023:10.1007/s00421-023-05150-2. [PMID: 36763123 DOI: 10.1007/s00421-023-05150-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/29/2023] [Indexed: 02/11/2023]
Abstract
Diabetes alters numerous physiological functions and can lead to disastrous consequences in the long term. Neuromuscular function is particularly affected and is impacted early, offering an opportunity to detect the onset of diabetes-related dysfunctions and follow the advancement of the disease. The role of physical training for counteracting the deleterious effects of diabetes is well accepted but at the same time, it appears difficult to reliably assess the effects of exercise on functional capacity in patients with diabetic peripheral neuropathy (DPN). In this paper, we will review the specific characteristics of various neuromuscular dysfunctions associated with diabetes according to the DPN presence or not, and their changes over time. We present several propositions regarding the onset of neuromuscular alterations in people with diabetes compared to people with DPN. It appears that motor unit loss and neuromuscular transmission impairment are among the main mechanisms explaining the considerable degradation of neuromuscular function in the transition from a diabetic to neuropathic state. Rate of force development and contractile properties could start to decrease with the onset of preferential type II fiber atrophy, commonly reported in people with DPN. Finally, Mmax amplitude could decrease with neuromuscular fatigue only in people with DPN, reflecting the fatigue-related neuromuscular transmission impairment reported in people with DPN. In this review, we show that the different neuromuscular parameters are altered at different stages of diabetes, according to the presence of DPN or not. The precise evaluation of these parameters might participate in adapting the physical training prescription.
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Affiliation(s)
- Antonin Le Corre
- IRISSE (EA 4075), UFR SHE, University of La Réunion, 117 Rue du Général Ailleret, 97430, Le Tampon, France.
| | - Nathan Caron
- IRISSE (EA 4075), UFR SHE, University of La Réunion, 117 Rue du Général Ailleret, 97430, Le Tampon, France
| | - Nicolas A Turpin
- IRISSE (EA 4075), UFR SHE, University of La Réunion, 117 Rue du Général Ailleret, 97430, Le Tampon, France
| | - Georges Dalleau
- IRISSE (EA 4075), UFR SHE, University of La Réunion, 117 Rue du Général Ailleret, 97430, Le Tampon, France
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5
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Bock JM, Hanson BE, Miller KA, Seaberg NT, Ueda K, Feider AJ, Hanada S, Lira VA, Casey DP. Eight weeks of inorganic nitrate/nitrite supplementation improves aerobic exercise capacity and the gas exchange threshold in patients with type 2 diabetes. J Appl Physiol (1985) 2022; 133:1407-1414. [PMID: 36326473 PMCID: PMC9762960 DOI: 10.1152/japplphysiol.00478.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022] Open
Abstract
Patients with type 2 diabetes mellitus (T2DM) have reduced exercise capacity, indexed by lower maximal oxygen consumption (V̇o2max) and achievement of the gas exchange threshold (GET) at a lower % V̇o2max. The ubiquitous signaling molecule nitric oxide (NO) plays a multifaceted role during exercise and, as patients with T2DM have poor endogenous NO production, we investigated if inorganic nitrate/nitrite supplementation (an exogenous source of NO) improves exercise capacity in patients with T2DM. Thirty-six patients with T2DM (10F, 59 ± 9 yr, 32.0 ± 5.1 kg/m2, HbA1c = 7.4 ± 1.4%) consumed beetroot juice containing either inorganic nitrate/nitrite (4.03 mmol/0.29 mmol) or a placebo (0.8 mmol/0.00 mmol) for 8 wk. A maximal exercise test was completed before and after both interventions. V̇o2max was determined by averaging 15-s data, whereas the GET was identified using the V-slope method and breath-by-breath data. Inorganic nitrate/nitrite increased both absolute (1.96 ± 0.67 to 2.07 ± 0.75 L/min) and relative (20.7 ± 7.0 to 21.9 ± 7.4 mL/kg/min, P < 0.05 for both) V̇o2max, whereas no changes were observed following placebo (1.94 ± 0.40 to 1.90 ± 0.39 L/min, P = 0.33; 20.0 ± 4.2 to 19.7 ± 4.6 mL/kg/min, P = 0.39). Maximal workload was also increased following inorganic nitrate/nitrite supplementation (134 ± 47 to 140 ± 51 W, P < 0.05) but not placebo (138 ± 32 to 138 ± 32 W, P = 0.98). V̇o2 at the GET (1.11 ± 0.27 to 1.27 ± 0.38L/min) and the %V̇o2max in which GET occurred (56 ± 8 to 61 ± 7%, P < 0.05 for both) increased following inorganic nitrate/nitrite supplementation but not placebo (1.10 ± 0.23 to 1.08 ± 0.21 L/min, P = 0.60; 57 ± 9 to 57 ± 8%, P = 0.90) although the workload at GET did not achieve statistical significance (group-by-time P = 0.06). Combined inorganic nitrate/nitrite consumption improves exercise capacity, maximal workload, and promotes a rightward shift in the GET in patients with T2DM. This manuscript reports data from a registered Clinical Trial at ClinicalTrials.gov ID: NCT02804932.NEW & NOTEWORTHY We report that increasing nitric oxide bioavailability via 8 wk of inorganic nitrate/nitrite supplementation improves maximal aerobic exercise capacity in patients with type 2 diabetes mellitus. Similarly, we observed a rightward shift in the gas exchange threshold. Taken together, these data indicate inorganic nitrate/nitrite may serve as a means to improve fitness in patients with type 2 diabetes mellitus.
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Affiliation(s)
- Joshua M Bock
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
| | - Brady E Hanson
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
| | - Kayla A Miller
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
| | - Nathanael T Seaberg
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
| | - Kenichi Ueda
- Department of Anesthesia, University of Iowa, Iowa City, Iowa
| | - Andrew J Feider
- Department of Anesthesia, University of Iowa, Iowa City, Iowa
| | - Satoshi Hanada
- Department of Anesthesia, University of Iowa, Iowa City, Iowa
| | - Vitor A Lira
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, Iowa
- Abboud Cardiovascular Research Center, University of Iowa, Iowa City, Iowa
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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6
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Wang AN, Fraser GM, McGuire JJ. Characterization of Endothelium-Dependent Relaxation in the Saphenous Artery and Its Caudal Branches in Young and Old Adult Sprague Dawley Rats. Biomolecules 2022; 12:biom12070889. [PMID: 35883445 PMCID: PMC9312764 DOI: 10.3390/biom12070889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/21/2022] [Accepted: 06/23/2022] [Indexed: 12/11/2022] Open
Abstract
Ageing is associated with reduced endothelium-derived nitric oxide (NO) production in the femoral artery of Sprague Dawley (SD) rats. In the current study, we examined endothelium-dependent relaxation (EDR) in the saphenous artery and its caudal branches. We used acetylcholine and the Proteinase-Activated receptor-2 (PAR2)-specific agonist (2fLIGRLO) with nitroarginine methylester (L-NAME) to assess EDR in two groups of male SD rats (age in weeks: young, 10–12; old, 27–29). Acetylcholine and 2fLIGRLO were potent NO-dependent relaxant agents in all arteries. For all arteries, EDR by acetylcholine decreased significantly in old compared to young SD rats. Interestingly, PAR2-induced EDR of proximal saphenous artery segments and caudal branches decreased significantly in old compared to young, but did not differ for the in-between middle and distal ends of the saphenous artery. L-NAME treatment increased subsequent contractions of proximal and middle segments of saphenous arteries by phenylephrine and U46619 in young, but not in old, SD rats. We conclude the SD saphenous artery and caudal branches exhibit regional characteristics that differ in response to specific EDR agonists, endothelial NO synthase inhibitor, and changes to endothelium function with increased age, which are, in part, attributed to decreased sensitivity of vascular smooth muscle to the gaseous transmitter NO.
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Affiliation(s)
- Andrea N. Wang
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5C1, Canada;
| | - Graham M. Fraser
- Division of BioMedical Sciences, Faculty of Medicine, Memorial University, St. John’s, NL A1B 3V6, Canada;
| | - John J. McGuire
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5C1, Canada;
- Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, ON N6A 5C1, Canada
- Correspondence:
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7
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Caterini JE, Rendall K, Cifra B, Schneiderman JE, Ratjen F, Seed M, Rayner T, Weiss R, McCrindle BW, Noseworthy MD, Williams CA, Barker AR, Wells GD. Non-invasive MR imaging techniques for measuring femoral arterial flow in a pediatric and adolescent cohort. Physiol Rep 2022; 10:e15182. [PMID: 35614568 PMCID: PMC9133543 DOI: 10.14814/phy2.15182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 11/24/2022] Open
Abstract
Magnetic Resonance Imaging (MRI) is well‐suited for imaging peripheral blood flow due to its non‐invasive nature and excellent spatial resolution. Although MRI is routinely used in adults to assess physiological changes in chronic diseases, there are currently no MRI‐based data quantifying arterial flow in pediatric or adolescent populations during exercise. Therefore the current research sought to document femoral arterial blood flow at rest and following exercise in a pediatric‐adolescent population using phase contrast MRI, and to present test‐retest reliability data for this method. Ten healthy children and adolescents (4 male; mean age 14.8 ± 2.4 years) completed bloodwork and resting and exercise MRI. Baseline images consisted of PC‐MRI of the femoral artery at rest and following a 5 × 30 s of in‐magnet exercise. To evaluate test‐retest reliability, five participants returned for repeat testing. All participants successfully completed exercise testing in the MRI. Baseline flow demonstrated excellent reliability (ICC = 0.93, p = 0.006), and peak exercise and delta rest‐peak flow demonstrated good reliability (peak exercise ICC = 0.89, p = 0.002, delta rest‐peak ICC = 0.87, p = 0.003) between‐visits. All three flow measurements demonstrated excellent reliability when assessed with coefficients of variance (CV’s) (rest: CV = 6.2%; peak exercise: CV = 7.3%; delta rest‐peak: CV = 7.1%). The mean bias was small for femoral arterial flow. There was no significant mean bias between femoral artery flow visits 1 and 2 at peak exercise. There were no correlations between age or height and any of the flow measurements. There were no significant differences between male and female participants for any of the flow measurements. The current study determined that peripheral arterial blood flow in children and adolescents can be evaluated using non‐invasive phase contrast MRI. The MRI‐based techniques that were used in the current study for measuring arterial flow in pediatric and adolescent patients demonstrated acceptable test‐retest reliability both at rest and immediately post‐exercise.
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Affiliation(s)
- Jessica E Caterini
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Graduate Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Kate Rendall
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Barbara Cifra
- Labatt Family Heart Centre, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jane E Schneiderman
- Division of Respiratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Felix Ratjen
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Division of Respiratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Mike Seed
- Labatt Family Heart Centre, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Tammy Rayner
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ruth Weiss
- Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brian W McCrindle
- Labatt Family Heart Centre, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Noseworthy
- Department of Electrical and Computer Engineering, McMaster University, Hamilton, Canada
| | - Craig A Williams
- Division of Respiratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.,Children's Health and Exercise Research Centre, Sport and Health Sciences, University of Exeter, Exeter, UK
| | - Alan R Barker
- Division of Respiratory Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Gregory D Wells
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
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8
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Lu YJ, Chen SY, Lai YC, Chaiyawat P, Chao YH, Chuang LM, Shih TTF, Wang HK. Muscle Microcirculatory Responses to Incremental Exercises Are Correlated with Peak Oxygen Uptake in Individuals With and Without Type 2 Diabetes Mellitus. Metab Syndr Relat Disord 2022; 20:405-413. [PMID: 35594301 DOI: 10.1089/met.2021.0101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Background: The role of impaired oxygen extraction on peak oxygen uptake (V̇O2peak) has been extensively studied using noninvasive and indirect methods in both diabetic patients and healthy participants. Methods: A total of 22 participants with type 2 diabetes mellitus [T2DM; median (range) age: 60 (47-70) years] and 22 controls [58 (52-69) years] with no history of diabetes were recruited (reference no. 201812135RINB). Subjects performed an exhaustive incremental exercise and were evaluated using a gas analyzer and near-infrared spectroscopy (NIRS) to determine V̇O2peak and changes in muscle oxygenation (SmO2) in the vastus lateralis, respectively. Measurements were taken at rest, warm-up, a period during exercise when SmO2 reached a minimum saturation plateau, and recovery. The microcirculatory responses of the vastus lateralis muscle during incremental exercise in patients with T2DM were compared with those in control individuals, and the correlation between changes in SmO2 and V̇O2peak was estimated. Results: The diabetic group demonstrated lower V̇O2peak, peak workload, peak heart rate, peak minute ventilation (all P < 0.05), and lower SmO2 during the rest, warm-up, and recovery phases (all P < 0.05) compared with the control group. A correlation was observed between the change in SmO2 between the warm-up and plateau value and the V̇O2peak (r = 0.608, P = 0.006). Conclusions: The results obtained in this study using NIRS support the feasibility of directly measuring changes in muscle SmO2 magnitudes to estimate the contributions of peripheral active muscle to systemic O2 uptake (V̇O2) during incremental exercise.
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Affiliation(s)
- Yan-Jhen Lu
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.,Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan
| | - Ssu-Yuan Chen
- Division of Physical Medicine and Rehabilitation, Fu Jen Catholic University Hospital, New Taipei City, Taiwan.,School of Medicine, College of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.,Department of Physical Medicine and Rehabilitation, College of Medicine, National Taiwan University, Taipei, Taiwan.,Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan
| | - Ying-Chuen Lai
- Division of Metabolism and Endocrinology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,College of Medicine, National Taiwan University, Taipei, Taiwan
| | | | - Yuan-Hung Chao
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.,Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan
| | - Lee-Ming Chuang
- Division of Metabolism and Endocrinology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.,College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Tiffany Ting-Fang Shih
- Department of Medical Image and Radiology, Medical College and Hospital, National Taiwan University, Taipei, Taiwan
| | - Hsing-Kuo Wang
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Taipei, Taiwan.,Center of Physical Therapy, National Taiwan University Hospital, Taipei, Taiwan
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Loai S, Sun X, Husain M, Laflamme MA, Yeger H, Nunes SS, Cheng HLM. Microvascular Dysfunction in Skeletal Muscle Precedes Myocardial Vascular Changes in Diabetic Cardiomyopathy: Sex-Dependent Differences. Front Cardiovasc Med 2022; 9:886687. [PMID: 35665251 PMCID: PMC9157579 DOI: 10.3389/fcvm.2022.886687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
AimTo uncover sex-related microvascular abnormalities that underlie the early presentation of reduced perfusion in leg skeletal muscle in a type II rat model of diabetic cardiomyopathy.Methods and ResultsDiabetes was induced using a non-obese, diet-based, low-dose streptozotocin model in adult female (18 diabetic, 9 control) and male rats (29 diabetic, 11 control). Time-course monitoring over 12 months following diabetes induction was performed using echocardiography, treadmill exercise, photoacoustic imaging, flow-mediated dilation (FMD), histopathology, and immunohistochemistry. Diabetic rats maintained normal weights. Hypertension appeared late in both diabetic males (7 months) and females (10 months), while only diabetic males had elevated cholesterol (7 months). On echocardiography, all diabetic animals maintained normal ejection fraction and exhibited diastolic dysfunction, mild systolic dysfunction, and a slightly enlarged left ventricle. Exercise tolerance declined progressively and early in males (4 months), later in females (8 months); FMD showed lower baseline femoral arterial flow but unchanged reactivity in both sexes (5 months); and photoacoustic imaging showed lower tissue oxygen saturation in the legs of diabetic males (4 months) and diabetic females (10 months). Myocardial perfusion was normal in both sexes. Histopathology at the final timepoint of Month 10 (males) and Month 12 (females) revealed that myocardial microvasculature was normal in both vessel density and structure, thus explaining normal perfusion on imaging. However, leg muscle microvasculature exhibited perivascular smooth muscle thickening around small arterioles in diabetic females and around large arterioles in diabetic males, explaining the depressed readings on photoacoustic and FMD. Histology also confirmed the absence of commonly reported HFpEF markers, including microvessel rarefaction, myocardial fibrosis, and left ventricular hypertrophy.ConclusionExercise intolerance manifesting early in the progression of diabetic cardiomyopathy can be attributed to decreased perfusion to the leg skeletal muscle due to perivascular smooth muscle thickening around small arterioles in females and large arterioles in males. This microvascular abnormality was absent in the myocardium, where perfusion levels remained normal throughout the study. We conclude that although skeletal muscle microvascular dysfunction of the vasculature presents at different levels depending on sex, it consistently presents early in both sexes prior to overt cardiac changes such as rarefaction, fibrosis, or hypertrophy.
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Affiliation(s)
- Sadi Loai
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada
| | - Xuetao Sun
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
| | - Mansoor Husain
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada
- Ted Rogers Centre for Heart Research, Toronto, ON, Canada
| | - Michael A. Laflamme
- Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
- Laboratory of Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Herman Yeger
- Laboratory of Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Sara S. Nunes
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Laboratory of Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Hai-Ling Margaret Cheng
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON, Canada
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada
- *Correspondence: Hai-Ling Margaret Cheng
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10
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Sonobe T, Tsuchimochi H, Maeda H, Pearson JT. Increased contribution of KCa channels to muscle contraction induced vascular and blood flow responses in sedentary and exercise trained ZFDM rats. J Physiol 2022; 600:2919-2938. [PMID: 35551673 DOI: 10.1113/jp282981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/04/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Microvascular dysfunction in type 2 diabetes impairs blood flow redistribution during exercise and limits the performance of skeletal muscle and may cause early fatigability. Endothelium-dependent hyperpolarization (EDH), which mediates vasodilation in resistance arteries is known to be depressed in animals with diabetes. Here we report that low-intensity exercise training in ZFDM rats increased KCa channel-derived component in the vasodilator responses to muscle contraction than in sedentary rats, partly due to the increase in KCNN3 expression. These results suggest that low-intensity exercise training improves blood flow redistribution in contracting skeletal muscle in metabolic disease with diabetes via upregulation of EDH. ABSTRACT In resistance arteries, endothelium-dependent hyperpolarization (EDH) mediated vasodilation is depressed in diabetes. We hypothesized that downregulation of KCa channel derived EDH reduces exercise-induced vasodilation and blood flow redistribution in diabetes. To test this hypothesis, we evaluated vascular function in response to hindlimb muscle contraction, and the contribution of KCa channels in anaesthetised ZFDM, metabolic disease rats with type 2 diabetes. We also tested whether exercise training ameliorated the vascular response. Using in vivo microangiography, the hindlimb vasculature was visualized before and after rhythmic muscle contraction (0.5 s tetanus every 3 sec, 20 times) evoked by sciatic nerve stimulation (40 Hz). Femoral blood flow of the contracting hindlimb was simultaneously measured by an ultrasonic flowmeter. The contribution of KCa channels was investigated in the presence and absence of apamin and charybdotoxin. We found that vascular and blood flow responses to muscle contraction were significantly impaired at the level of small artery segments in ZFDM fa/fa rats compared to its lean control fa/+ rats. The contribution of KCa channels was also smaller in fa/fa than in fa/+ rats. Low-intensity exercise training for 12 weeks in fa/fa rats demonstrated minor changes in the vascular and blood flow response to muscle contraction. However, KCa-derived component in the response to muscle contraction was much greater in exercise trained than in sedentary fa/fa rats. These data suggest that exercise training increases the contribution of KCa channels among endothelium-dependent vasodilatory mechanisms to maintain vascular and blood flow responses to muscle contraction in this metabolic disease rat model. Abstract figure legend Low-intensity exercise training in ZFDM, metabolic disease rats with type 2 diabetes increases KCa channel-derived component of endothelium-dependent hyperpolarization in the vascular and blood flow responses to skeletal muscle contraction than the responses in sedentary rats, partly due to upregulation of KCNN3 protein expression. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Takashi Sonobe
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hisashi Maeda
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.,Victoria Heart Institute and Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Australia
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11
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Bock JM, Ueda K, Feider AJ, Hanada S, Casey DP. Combined inorganic nitrate/nitrite supplementation blunts α-mediated vasoconstriction during exercise in patients with type 2 diabetes. Nitric Oxide 2021; 118:17-25. [PMID: 34718145 DOI: 10.1016/j.niox.2021.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/21/2021] [Accepted: 10/25/2021] [Indexed: 11/28/2022]
Abstract
AIMS Patients with type 2 diabetes mellitus (T2DM) have reduced vasodilatory responses during exercise partially attributable to low nitric oxide (NO) levels. Low NO contributes to greater α-adrenergic mediated vasoconstriction in contracting skeletal muscle. We hypothesized boosting NO bioavailability via 8wks of active beetroot juice (BRA, 4.03 mmol nitrate, 0.29 mmol nitrite, n = 19) improves hyperemia, via reduced α-mediated vasoconstriction, during handgrip exercise relative to nitrate/nitrite-depleted beetroot juice (BRP, n = 18) in patients with T2DM. METHODS Forearm blood flow (FBF) and vascular conductance (FVC) were calculated at rest and during handgrip exercise (20%max, 20contractions·min-1). Phenylephrine (α1-agonist) and dexmedetomidine (α2-agonist) were infused intra-arterially during independent trials to determine the influence of α-mediated vasoconstriction on exercise hyperemia. Vasoconstriction was quantified as the percent-reduction in FVC during α-agonist infusion, relative to pre-infusion, as well as the absolute change in %FVC during exercise relative to the respective rest trial (magnitude of sympatholysis). RESULTS ΔFBF (156 ± 69 to 175 ± 73 ml min-1) and ΔFVC (130 ± 54 to 156 ± 63 ml min-1·100 mmHg-1, both P < 0.05) during exercise were augmented following BRA, but not BRP (P = 0.96 and 0.51). Phenylephrine-induced vasoconstriction during exercise was blunted following BRA (-17.1 ± 5.9 to -12.6 ± 3.1%, P < 0.01), but not BRP (P = 0.58) supplementation; the magnitude of sympatholysis was unchanged by either (beverage-by-time P = 0.15). BRA supplementation reduced dexmedetomidine-induced vasoconstriction during exercise (-23.3 ± 6.7 to -19.7 ± 5.2%) and improved the corresponding magnitude of sympatholysis (25.3 ± 11.4 to 34.4 ± 15.5%, both P < 0.05). CONCLUSIONS BRA supplementation improves the hyperemic and vasodilatory responses to exercise in patients with T2DM which appears to be attributable to reduced α-adrenergic mediated vasoconstriction in contracting skeletal muscle.
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Affiliation(s)
- Joshua M Bock
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, USA
| | - Andrew J Feider
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, USA
| | - Satoshi Hanada
- Department of Anesthesia, Carver College of Medicine, University of Iowa, 200 Hawkins Dr, Iowa City, IA, USA
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, IA, USA; Abboud Cardiovascular Research Center, University of Iowa, 285 Newton Rd, Iowa City, IA, USA; Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, 169 Newton Rd, IA, USA.
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12
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Grotle AK, Kaur J, Stone AJ, Fadel PJ. Neurovascular Dysregulation During Exercise in Type 2 Diabetes. Front Physiol 2021; 12:628840. [PMID: 33927637 PMCID: PMC8076798 DOI: 10.3389/fphys.2021.628840] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/05/2021] [Indexed: 12/12/2022] Open
Abstract
Emerging evidence suggests that type 2 diabetes (T2D) may impair the ability to properly adjust the circulation during exercise with augmented blood pressure (BP) and an attenuated contracting skeletal muscle blood flow (BF) response being reported. This review provides a brief overview of the current understanding of these altered exercise responses in T2D and the potential underlying mechanisms, with an emphasis on the sympathetic nervous system and its regulation during exercise. The research presented support augmented sympathetic activation, heightened BP, reduced skeletal muscle BF, and impairment in the ability to attenuate sympathetically mediated vasoconstriction (i.e., functional sympatholysis) as potential drivers of neurovascular dysregulation during exercise in T2D. Furthermore, emerging evidence supporting a contribution of the exercise pressor reflex and central command is discussed along with proposed future directions for studies in this important area of research.
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Affiliation(s)
- Ann-Katrin Grotle
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, United States
| | - Jasdeep Kaur
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States
| | - Audrey J Stone
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States
| | - Paul J Fadel
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, United States
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13
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Power LC, Gusso S, Hornung TS, Jefferies C, Derraik JGB, Hofman PL, O'Grady GL. Exercise Cardiac Magnetic Resonance Imaging in Boys With Duchenne Muscular Dystrophy Without Cardiac Disease. Pediatr Neurol 2021; 117:35-43. [PMID: 33662889 DOI: 10.1016/j.pediatrneurol.2020.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Duchenne muscular dystrophy is caused by mutations in the DMD gene, resulting in cardiomyopathy in all affected children by 18 years. Although cardiomyopathy is now the leading cause of mortality in these children, there is ongoing debate regarding timely diagnosis, secondary prevention, and treatment of this condition. The purpose of this study was to use exercise cardiac magnetic resonance imaging in asymptomatic young boys with Duchenne muscular dystrophy to describe their heart function and compare this with healthy controls. METHODS We studied 11 boys with Duchenne muscular dystrophy aged 8.6 to 13.9 years and 11 healthy age- and sex-matched controls. RESULTS Compared with the controls, boys with Duchenne muscular dystrophy had lower ejection fraction at rest (57% versus 63%; P = 0.004). During submaximal exercise, they reached similar peak tachycardia but increased their heart rate and cardiac output only half as much as controls (P = 0.003 and P = 0.014, respectively). End-systolic volume remained higher in boys with Duchenne muscular dystrophy both at rest and during exercise. When transthoracic echocardiography was compared with cardiac magnetic resonance imaging, 45% of the echocardiograms had suboptimal or poor views in the Duchenne muscular dystrophy group. CONCLUSIONS Boys with Duchenne muscular dystrophy had abnormalities in left ventricular systolic function that were exaggerated by exercise stress. Exercise cardiac magnetic resonance imaging is feasible in a select population of children with Duchenne muscular dystrophy, and it has the potential to unmask early signs of cardiomyopathy.
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Affiliation(s)
- Lisa C Power
- Paediatric Neurology Department, Starship Children's Hospital, Auckland, New Zealand; Paediatric Endocrinology Department, Starship Children's Hospital, Auckland, New Zealand; Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Silmara Gusso
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand
| | - Tim S Hornung
- Paediatric Cardiology Department, Starship Children's Hospital, Auckland, New Zealand
| | - Craig Jefferies
- Paediatric Endocrinology Department, Starship Children's Hospital, Auckland, New Zealand
| | - José G B Derraik
- Liggins Institute, University of Auckland, Auckland, New Zealand; Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Paul L Hofman
- Paediatric Endocrinology Department, Starship Children's Hospital, Auckland, New Zealand; Liggins Institute, University of Auckland, Auckland, New Zealand
| | - Gina L O'Grady
- Paediatric Neurology Department, Starship Children's Hospital, Auckland, New Zealand.
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14
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Gildea N, McDermott A, Rocha J, O'Shea D, Green S, Egaña M. Time-course of V̇o 2 kinetics responses during moderate-intensity exercise subsequent to HIIT versus moderate-intensity continuous training in type 2 diabetes. J Appl Physiol (1985) 2021; 130:1646-1659. [PMID: 33792400 DOI: 10.1152/japplphysiol.00952.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We assessed the time-course of changes in oxygen uptake (V̇o2) and muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin, [HHb + Mb]) kinetics during transitions to moderate-intensity cycling following 12 wk of low-volume high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MICT) in adults with type 2 diabetes (T2D). Participants were randomly assigned to MICT (n = 10, 50 min of moderate-intensity cycling), HIIT (n = 9, 10 × 1 min at ∼90% maximal heart rate), or nonexercising control (n = 9) groups. Exercising groups trained three times per week, and measurements were taken every 3 wk. [HHb + Mb] kinetics were measured by near-infrared spectroscopy at the vastus lateralis muscle. The local matching of O2 delivery to O2 utilization was assessed by the Δ[HHb + Mb]/ΔV̇o2 ratio. The pretraining time constant of the primary phase of V̇o2 (τV̇o2p) decreased (P < 0.05) at wk 3 of training in both MICT (from 44 ± 12 to 32 ± 5 s) and HIIT (from 42 ± 8 to 32 ± 4 s) with no further changes thereafter, whereas no changes were reported in controls. The pretraining overall dynamic response of muscle deoxygenation (τ'[HHb + Mb]) was faster than τV̇o2p in all groups, resulting in Δ[HHb + Mb]/V̇o2p showing a transient "overshoot" relative to the subsequent steady-state level. After 3 wk, the Δ[HHb + Mb]/V̇o2p overshoot was eliminated only in the training groups, so that τ'[HHb + Mb] was not different to τV̇o2p in MICT and HIIT. The enhanced V̇o2 kinetics response consequent to both MICT and HIIT in T2D was likely attributed to a training-induced improvement in matching of O2 delivery to utilization.NEW & NOTEWORTHY High-intensity interval training and moderate-intensity continuous training elicited faster pulmonary oxygen uptake (V̇o2) kinetics during moderate-intensity cycling within 3 wk of training with no further changes thereafter in individuals with type 2 diabetes. These adaptations were accompanied by unaltered near-infrared spectroscopy-derived muscle deoxygenation (i.e. deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) kinetics and transiently reduced Δ[HHb+Mb]-to-ΔV̇o2 ratio, suggesting an enhanced blood flow distribution within the active muscles subsequent to both training interventions.
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Affiliation(s)
- Norita Gildea
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Adam McDermott
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Joel Rocha
- Division of Sport and Exercise Sciences, Abertay University, Dundee, United Kingdom
| | - Donal O'Shea
- Department of Endocrinology, St. Columcille's Hospital, Dublin, Ireland.,Department of Endocrinology and Diabetes Mellitus, St. Vincent's University Hospital, Dublin, Ireland
| | - Simon Green
- Schools of Health Sciences and Medicine, Western Sydney University, Sydney, Australia
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
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15
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Van Ryckeghem L, Keytsman C, Verboven K, Verbaanderd E, Frederix I, Bakelants E, Petit T, Jogani S, Stroobants S, Dendale P, Bito V, Verwerft J, Hansen D. Exercise capacity is related to attenuated responses in oxygen extraction and left ventricular longitudinal strain in asymptomatic type 2 diabetes patients. Eur J Prev Cardiol 2020; 28:1756-1766. [PMID: 33623980 DOI: 10.1093/eurjpc/zwaa007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/09/2020] [Accepted: 07/09/2020] [Indexed: 12/26/2022]
Abstract
AIMS Type 2 diabetes mellitus (T2DM) is associated with reduced exercise capacity and cardiovascular diseases, both increasing morbidity and risk for premature death. As exercise intolerance often relates to cardiac dysfunction, it remains to be elucidated to what extent such an interplay occurs in T2DM patients without overt cardiovascular diseases. Design: Cross-sectional study, NCT03299790. METHODS AND RESULTS Fifty-three T2DM patients underwent exercise echocardiography (semi-supine bicycle) with combined ergospirometry. Cardiac output (CO), left ventricular longitudinal strain (LS), oxygen uptake (O2), and oxygen (O2) extraction were assessed simultaneously at rest, low-intensity exercise, and high-intensity exercise. Glycaemic control and lipid profile were assessed in the fasted state. Participants were assigned according to their exercise capacity being adequate or impaired (EXadequate: O2peak <80% and EXimpaired: O2peak ≥80% of predicted O2peak) to compare O2 extraction, CO, and LS at all stages. Thirty-eight participants (EXimpaired: n = 20 and EXadequate: n = 18) were included in the analyses. Groups were similar regarding HbA1c, age, and sex (P > 0.05). At rest, CO was similar in the EXimpaired group vs. EXadequate group (5.1 ± 1 L/min vs. 4.6 ± 1.4 L/min, P > 0.05) and increased equally during exercise. EXimpaired patients displayed a 30.7% smaller increase in O2 extraction during exercise compared to the EXadequate group (P = 0.016) which resulted in a lower O2 extraction at high-intensity exercise (12.5 ± 2.8 mL/dL vs. 15.3 ± 3.9 mL/dL, P = 0.012). Left ventricular longitudinal strain was similar at rest but increased significantly less in the EXimpaired vs. EXadequate patients (1.9 ± 2.5% vs. 5.9 ± 4.1%, P = 0.004). CONCLUSIONS In asymptomatic T2DM patients, an impaired exercise capacity is associated with an impaired response in oxygen extraction and myocardial deformation (LS). TRIAL REGISTRY Effect of High-intensity Interval Training on Cardiac Function and Regulation of Glycemic Control in Diabetic Cardiomyopathy (https://clinicaltrials.gov/ct2/show/NCT03299790).
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Affiliation(s)
| | - Charly Keytsman
- Department of REVAL - Rehabilitation Research Centre, Faculty of Rehabilitation Sciences, Hasselt University, Belgium.,Department of BIOMED - Biomedical Research Centre, Faculty of Medicine and Life Sciences, Hasselt University, Belgium
| | - Kenneth Verboven
- Department of REVAL - Rehabilitation Research Centre, Faculty of Rehabilitation Sciences, Hasselt University, Belgium.,Department of BIOMED - Biomedical Research Centre, Faculty of Medicine and Life Sciences, Hasselt University, Belgium
| | - Elvire Verbaanderd
- Physical Activity, Department of Sport & Health Research Group, Faculty of Movement Sciences, KU Leuven, Leuven, Belgium
| | - Ines Frederix
- Department of BIOMED - Biomedical Research Centre, Faculty of Medicine and Life Sciences, Hasselt University, Belgium.,Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium.,Department Genetics, Pharmacology and Physiopathology of Heart, Blood Vessels and Skeleton (GENCOR), Faculty of Medicine & Health Sciences, Antwerp University, Antwerp, Belgium.,Department of Cardiology, Antwerp University Hospital, Edegem, Belgium
| | - Elise Bakelants
- Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium.,Department of cardiology, Hôpitaux Universitaires de Genève (HUG), Genève, Switzerland
| | - Thibault Petit
- Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium.,Department of Cardiology, Hospital Oost-Limburg, Genk, Belgium
| | - Siddharth Jogani
- Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium
| | - Sarah Stroobants
- Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium
| | - Paul Dendale
- Department of BIOMED - Biomedical Research Centre, Faculty of Medicine and Life Sciences, Hasselt University, Belgium.,Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium
| | - Virginie Bito
- Department of BIOMED - Biomedical Research Centre, Faculty of Medicine and Life Sciences, Hasselt University, Belgium
| | - Jan Verwerft
- Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium
| | - Dominique Hansen
- Department of REVAL - Rehabilitation Research Centre, Faculty of Rehabilitation Sciences, Hasselt University, Belgium.,Department of BIOMED - Biomedical Research Centre, Faculty of Medicine and Life Sciences, Hasselt University, Belgium.,Department of Cardiology, Virga Jessa Hospital, Heart Centre Hasselt, Hasselt, Belgium
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16
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Effect of a Single Session of Intermittent Hypoxia on Erythropoietin and Oxygen-Carrying Capacity. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17197257. [PMID: 33020411 PMCID: PMC7579477 DOI: 10.3390/ijerph17197257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 12/24/2022]
Abstract
Intermittent hypoxia, defined as alternating bouts of breathing hypoxic and normoxic air, has the potential to improve oxygen-carrying capacity through an erythropoietin-mediated increase in hemoglobin mass. The purpose of this study was to determine the effect of a single session of intermittent hypoxia on erythropoietin levels and hemoglobin mass in young healthy individuals. Nineteen participants were randomly assigned to an intermittent hypoxia group (Hyp, n = 10) or an intermittent normoxia group (Norm, n = 9). Intermittent hypoxia consisted of five 4-min hypoxic cycles at a targeted arterial oxygen saturation of 90% interspersed with 4-min normoxic cycles. Erythropoietin levels were measured before and two hours following completion of the protocol. Hemoglobin mass was assessed the day before and seven days after exposure to intermittent hypoxia or normoxia. As expected, the intermittent hypoxia group had a lower arterial oxygen saturation than the intermittent normoxia group during the intervention (Hyp: 89 ± 1 vs. Norm: 99 ± 1%, p < 0.01). Erythropoietin levels did not significantly increase following exposure to intermittent hypoxia (Hyp: 8.2 ± 4.5 to 9.0 ± 4.8, Norm: 8.9 ± 1.7 to 11.1 ± 2.1 mU·mL−1, p = 0.15). Hemoglobin mass did not change following exposure to intermittent hypoxia. This single session of intermittent hypoxia was not sufficient to elicit a significant rise in erythropoietin levels or hemoglobin mass in young healthy individuals.
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17
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Bock JM, Hughes WE, Ueda K, Feider AJ, Hanada S, Kruse NT, Iwamoto E, Casey DP. Greater α1-adrenergic-mediated vasoconstriction in contracting skeletal muscle of patients with type 2 diabetes. Am J Physiol Heart Circ Physiol 2020; 319:H797-H807. [DOI: 10.1152/ajpheart.00532.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Findings presented in this article are the first to show patients with type 2 diabetes mellitus have blunted hyperemic and vasodilatory responses to dynamic handgrip exercise. Moreover, we illustrate greater α1-adrenergic-mediated vasoconstriction may contribute to our initial observations. Collectively, these data suggest patients with type 2 diabetes may have impaired functional sympatholysis, which can contribute to their reduced exercise capacity.
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Affiliation(s)
- Joshua M. Bock
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - William E. Hughes
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Kenichi Ueda
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Andrew J. Feider
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Satoshi Hanada
- Department of Anesthesia, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Nicholas T. Kruse
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
- Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Erika Iwamoto
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
- School of Health Sciences, Sapporo Medical University, Sapporo, Japan
| | - Darren P. Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
- Abboud Cardiovascular Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa
- Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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18
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Nesti L, Pugliese NR, Sciuto P, Natali A. Type 2 diabetes and reduced exercise tolerance: a review of the literature through an integrated physiology approach. Cardiovasc Diabetol 2020; 19:134. [PMID: 32891175 PMCID: PMC7487838 DOI: 10.1186/s12933-020-01109-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 08/29/2020] [Indexed: 12/14/2022] Open
Abstract
The association between type 2 diabetes mellitus (T2DM) and heart failure (HF) is well established. Early in the course of the diabetic disease, some degree of impaired exercise capacity (a powerful marker of health status with prognostic value) can be frequently highlighted in otherwise asymptomatic T2DM subjects. However, the literature is quite heterogeneous, and the underlying pathophysiologic mechanisms are far from clear. Imaging-cardiopulmonary exercise testing (CPET) is a non-invasive, provocative test providing a multi-variable assessment of pulmonary, cardiovascular, muscular, and cellular oxidative systems during exercise, capable of offering unique integrated pathophysiological information. With this review we aimed at defying the cardiorespiratory alterations revealed through imaging-CPET that appear specific of T2DM subjects without overt cardiovascular or pulmonary disease. In synthesis, there is compelling evidence indicating a reduction of peak workload, peak oxygen assumption, oxygen pulse, as well as ventilatory efficiency. On the contrary, evidence remains inconclusive about reduced peripheral oxygen extraction, impaired heart rate adjustment, and lower anaerobic threshold, compared to non-diabetic subjects. Based on the multiparametric evaluation provided by imaging-CPET, a dissection and a hierarchy of the underlying mechanisms can be obtained. Here we propose four possible integrated pathophysiological mechanisms, namely myocardiogenic, myogenic, vasculogenic and neurogenic. While each hypothesis alone can potentially explain the majority of the CPET alterations observed, seemingly different combinations exist in any given subject. Finally, a discussion on the effects -and on the physiological mechanisms-of physical activity and exercise training on oxygen uptake in T2DM subjects is also offered. The understanding of the early alterations in the cardiopulmonary response that are specific of T2DM would allow the early identification of those at a higher risk of developing HF and possibly help to understand the pathophysiological link between T2DM and HF.
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Affiliation(s)
- Lorenzo Nesti
- Metabolism, Nutrition and Atherosclerosis Lab, Dietologia Universitaria, Pisa, Italy. .,Cardiopulmonary Test Lab, Department of Clinical and Experimental Medicine, University of Pisa, Via Savi 10, 56126, Pisa, Italy.
| | - Nicola Riccardo Pugliese
- Cardiopulmonary Test Lab, Department of Clinical and Experimental Medicine, University of Pisa, Via Savi 10, 56126, Pisa, Italy
| | - Paolo Sciuto
- Metabolism, Nutrition and Atherosclerosis Lab, Dietologia Universitaria, Pisa, Italy
| | - Andrea Natali
- Metabolism, Nutrition and Atherosclerosis Lab, Dietologia Universitaria, Pisa, Italy
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Miyamoto T, Watanabe K, Fukuda K, Moritani T. Near-infrared Spectroscopy of Vastus Lateralis Muscle during Incremental Cycling Exercise in patients with Type 2 Diabetes. Phys Ther Res 2020; 23:23-30. [PMID: 32850275 DOI: 10.1298/ptr.e9984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 09/21/2019] [Indexed: 11/23/2022]
Abstract
PURPOSE It is clinically important to elucidate the precise mechanism of exercise intolerance in patients with type 2 diabetes (T2DM). The aim of this study was to examine whether there is a difference in the time course change of the oxygenation in the vastus lateralis (VL) muscle during submaximal incremental cycling exercise between patients with T2DM and age-matched healthy subjects. METHODS Nine elderly men with T2DM and 10 age-matched healthy men (CON) participated in this study. All participants performed an incremental cycling exercise.Total, deoxygenated and oxygenated hemoglobin/myoglobin in the VL muscle were assessed using near-infrared spectroscopy, and cardiorespiratory response was also evaluated during the exercise. RESULTS There were no significant differences in the time course changes of deoxygenated hemoglobin/myoglobin between groups ( p > 0.05). However, the oxygenated hemoglobin/myoglobin in T2DM was significantly higher than that in CON at an intensity above ventilatory threshold during the incremental cycling exercise ( p< 0.05). CONCLUSION This study suggests that patients with T2DM had early limitation of oxygen extraction and lower capacity of oxygenated myoglobin dissociation in the VL muscle. The fact that patients with T2DM showed different oxygen kinetics in a peripheral tissue from healthy subjects may partly explain the potential mechanisms of exercise intolerance in T2DM.
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Affiliation(s)
| | - Kohei Watanabe
- School of International Liberal Studies, Chukyo University
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20
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Abstract
Functional capacity represents an important predictor for cardiovascular and all-cause mortality in patients with diabetes mellitus (DM). Impaired cardiopulmonary fitness is frequently seen in DM patients, and it might partly explain morbidity and mortality in these patients. There are several potential reasons that could explain impaired functional capacity in DM patients: hyperglycemia, insulin resistance, endothelial dysfunction, inflammation, microvascular impairment, myocardial dysfunction, and skeletal muscle changes. These changes are partly reversible, and improvement of any of these components might increase functional capacity in DM patients and improve their outcome. Physical activity is related with decreased cardiovascular disease and all-cause mortality in patients with type 2 DM. Diabetic cardiomyopathy is the most important clinical entity in DM patients that involves left ventricular diastolic dysfunction and cardiac autonomic neuropathy, which potentially induce heart failure with preserved ejection fraction. Development of diabetic cardiomyopathy may slow oxygen uptake kinetics and affect the cardiorespiratory fitness in DM patients, but it can also induce development of heart failure. Improvement of functional capacity in DM patients represents an important therapeutic task, and it can be achieved mainly with exercise training and significantly less with pharmacological treatment. Exercise training reduces body weight and improves glycemic control, as well as left ventricular structure and function. The aim of this review was to summarize current knowledge about importance of functional capacity in DM patients, as well as possible mechanisms that could explain the relationship between DM and oxygen kinetics.
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Grotle AK, Macefield VG, Farquhar WB, O'Leary DS, Stone AJ. Recent advances in exercise pressor reflex function in health and disease. Auton Neurosci 2020; 228:102698. [PMID: 32861944 DOI: 10.1016/j.autneu.2020.102698] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 01/11/2023]
Abstract
Autonomic alterations at the onset of exercise are critical to redistribute cardiac output towards the contracting muscles while preventing a fall in arterial pressure due to excessive vasodilation within the contracting muscles. Neural mechanisms responsible for these adjustments include central command, the exercise pressor reflex, and arterial and cardiopulmonary baroreflexes. The exercise pressor reflex evokes reflex increases in sympathetic activity to the heart and systemic vessels and decreases in parasympathetic activity to the heart, which increases blood pressure (BP), heart rate, and total peripheral resistance through vasoconstriction of systemic vessels. In this review, we discuss recent advancements in our understanding of exercise pressor reflex function in health and disease. Specifically, we discuss emerging evidence suggesting that sympathetic vasoconstrictor drive to the contracting and non-contracting skeletal muscle is differentially controlled by central command and the metaboreflex in healthy conditions. Further, we discuss evidence from animal and human studies showing that cardiovascular diseases, including hypertension, diabetes, and heart failure, lead to an altered exercise pressor reflex function. We also provide an update on the mechanisms thought to underlie this altered exercise pressor reflex function in each of these diseases. Although these mechanisms are complex, multifactorial, and dependent on the etiology of the disease, there is a clear consensus that several mechanisms are involved. Ultimately, approaches targeting these mechanisms are clinically significant as they provide alternative therapeutic strategies to prevent adverse cardiovascular events while also reducing symptoms of exercise intolerance.
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Affiliation(s)
- Ann-Katrin Grotle
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States of America
| | | | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, United States of America
| | - Donal S O'Leary
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Audrey J Stone
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States of America.
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22
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Green S, Kiely C, O'Connor E, Gildea N, O'Shea D, Egaña M. Effects of exercise training and sex on dynamic responses of O 2 uptake in type 2 diabetes. Appl Physiol Nutr Metab 2020; 45:865-874. [PMID: 32134683 DOI: 10.1139/apnm-2019-0636] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Effects of training and sex on oxygen uptake dynamics during exercise in type 2 diabetes mellitus (T2DM) are not well established. We tested the hypotheses that exercise training improves the time constant of the primary phase of oxygen uptake (τp oxygen uptake) and with greater effect in males than females. Forty-one subjects with T2DM were assigned to 2 training groups (Tmale, Tfemale) and 2 control groups (Cmale, Cfemale), and were assessed before and after a 12-week intervention period. Twelve weeks of aerobic/resistance training was performed 3 times per week, 60-90 min per session. Assessments included ventilatory threshold (VT), peak oxygen uptake, τp oxygen uptake (80%VT), and dynamic responses of cardiac output, mean arterial pressure and systemic vascular conductance (80%VT). Training significantly decreased τp oxygen uptake in males by a mean of 20% (Tmale = 42.7 ± 6.2 to 34.3 ± 7.2 s) and females by a mean of 16% (Tfemale = 42.2 ± 9.3 to 35.4 ± 8.6 s); whereas τp oxygen uptake was not affected in controls (Cmale = 41.6 ± 9.8 to 42.9 ± 7.6 s; Cfemale = 40.4 ± 12.2 to 40.6 ± 13.4 s). Training increased peak oxygen uptake in both sexes (12%-13%) but did not alter systemic cardiovascular dynamics in either sex. Training improved oxygen uptake dynamics to a similar extent in males and females in the absence of changes in systemic cardiovascular dynamics. Novelty Similar training improvements in oxygen uptake dynamics were observed in males and females with T2DM. In both sexes these improvements occurred without changes in systemic cardiovascular dynamics.
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Affiliation(s)
- Simon Green
- School of Science and Health, Western Sydney University, Sydney 2567, Australia.,School of Medicine, Western Sydney University, Sydney 2567, Australia
| | - Catherine Kiely
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Eamonn O'Connor
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Norita Gildea
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Donal O'Shea
- Endocrinology, St Columcille's and St Vincent's Hospitals, Dublin, Dublin 18, Ireland
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
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Federau C, Kroismayr D, Dyer L, Farshad M, Pfirrmann C. Demonstration of asymmetric muscle perfusion of the back after exercise in patients with adolescent idiopathic scoliosis using intravoxel incoherent motion (IVIM) MRI. NMR IN BIOMEDICINE 2020; 33:e4194. [PMID: 31815323 DOI: 10.1002/nbm.4194] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/31/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
The purpose of this work was to quantify muscular perfusion patterns of back muscles after exercise in patients with adolescent idiopathic scoliosis (AIS) using intravoxel incoherent motion (IVIM) MR perfusion imaging. The paraspinal muscles of eight patients with AIS (Cobb angle 35 ± 10°, range [25-47°]) and nine healthy volunteers were scanned with a 1.5 T MRI, at rest and after performing a symmetric back muscle exercise on a Roman chair. An IVIM sequence with 16 b-values from 0 to 900 s/mm2 was acquired, and the IVIM bi-exponential signal equation model was fitted in two steps. Perfusion asymmetries were evaluated using the blood flow related IVIM fD* parameter in regions of interest placed within the paraspinal muscles. Statistical significance was assessed using a Student t-test. The observed perfusion pattern after performing a Roman chair muscle exercise differed consistently in patients with AIS compared with healthy normal volunteers, and consisted of an asymmetrical increase in IVIM fD* [10-3 mm2 /s] above the lumbar convexity from 6.5 ± 5.8 to 28.8 ± 26.8 (p < 0.005), with no increase in the concavity (decrease from 6.5 ± 10.0 to 3.2 ± 1.5 (p = 0.19)), compared with a bilateral symmetric increase in the healthy volunteers (right, increase from 3.3 ± 2.1 to 10.1 ± 4.6 (p < 0.05); left, 6.7 ± 10.7 to 13.3 ± 7.0 (p < 0.05)). In conclusion, patients with AIS exhibit significant asymmetric muscle perfusion over the convexity of the scoliotic curvature after Roman chair exercise.
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Affiliation(s)
- Christian Federau
- Radiology, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH Zürich und University of Zürich, Zürich, Switzerland
| | - Daniela Kroismayr
- Radiology, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Linda Dyer
- Division of Spine Surgery, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Mazda Farshad
- Division of Spine Surgery, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Christian Pfirrmann
- Radiology, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
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Grotle AK, Stone AJ. Exaggerated exercise pressor reflex in type 2 diabetes: Potential role of oxidative stress. Auton Neurosci 2019; 222:102591. [PMID: 31669797 PMCID: PMC6858935 DOI: 10.1016/j.autneu.2019.102591] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 02/08/2023]
Abstract
Type 2 diabetes mellitus (T2DM) leads to exaggerated cardiovascular responses to exercise, in part due to an exaggerated exercise pressor reflex. Accumulating data suggest excessive oxidative stress contributes to an exaggerated exercise pressor reflex in cardiovascular-related diseases. Excessive oxidative stress is also a primary underlying mechanism for the development and progression of T2DM. However, whether oxidative stress plays a role in mediating the exaggerated exercise pressor reflex in T2DM is not known. Therefore, this review explores the potential role of oxidative stress leading to increased activation of the afferent arm of the exercise pressor reflex. Several lines of evidence support direct and indirect effects of oxidative stress on the exercise pressor reflex. For example, intramuscular ROS may directly and indirectly (by attenuating contracting muscle blood flow) increase group III and IV afferent activity. Oxidative stress is a primary underlying mechanism for the development of neuropathic pain, which in turn is associated with increased group III and IV afferent activity. These are the same type of afferents that evoke muscle pain and the exercise pressor reflex. Furthermore, oxidative stress-induced release of inflammatory mediators may modulate afferent activity. Collectively, these alterations may result in a positive feedback loop that further amplifies the exercise pressor reflex. An exaggerated reflex increases the risk of adverse cardiovascular events. Thus, identifying the contribution of oxidative stress could provide a potential therapeutic target to reduce this risk in T2DM.
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Affiliation(s)
- Ann-Katrin Grotle
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX 78712, United States of America
| | - Audrey J Stone
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX 78712, United States of America.
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25
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Rocha J, Gildea N, O’Shea D, Green S, Egaña M. Influence of priming exercise on oxygen uptake and muscle deoxygenation kinetics during moderate-intensity cycling in type 2 diabetes. J Appl Physiol (1985) 2019; 127:1140-1149. [DOI: 10.1152/japplphysiol.00344.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pulmonary oxygen uptake (V̇o2) kinetics during the transition to moderate-intensity exercise is slowed in individuals with type 2 diabetes (T2D), at least in part because of limitations in O2 delivery. The present study tested the hypothesis that a prior heavy-intensity warm-up or “priming” exercise (PE) bout would accelerate V̇o2 kinetics in T2D, because of a better matching of O2 delivery to utilization. Twelve middle-aged individuals with T2D and 12 healthy controls (ND) completed moderate-intensity constant-load cycling bouts either without (Mod A) or with (Mod B) prior PE. The rates of muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) and oxygenation (i.e., tissue oxygenation index) were continuously measured by near-infrared spectroscopy at the vastus lateralis muscle. The local matching of O2 delivery to O2 utilization was assessed by the Δ[HHb+Mb]-to-ΔV̇o2 ratio. Both groups demonstrated an accelerated V̇O2 kinetics response during Mod B compared with Mod A (T2D, 32 ± 9 vs. 42 ± 12 s; ND, 28 ± 9 vs. 34 ± 8 s; means ± SD) and an elevated muscle oxygenation throughout Mod B, whereas the [HHb+Mb] amplitude was greater during Mod B only in individuals with T2D. The [HHb+Mb] kinetics remained unchanged in both groups. In T2D, Mod B was associated with a decrease in the “overshoot” relative to steady state in the Δ[HHb+Mb]-to-ΔV̇o2 ratio (1.17 ± 0.17 vs. 1.05 ± 0.15), whereas no overshoot was observed in the control group before (1.04 ± 0.12) or after (1.01 ± 0.12) PE. Our findings support a favorable priming-induced acceleration of the V̇o2 kinetics response in middle-aged individuals with uncomplicated T2D attributed to an enhanced matching of microvascular O2 delivery to utilization. NEW & NOTEWORTHY Heavy-intensity “priming” exercise (PE) elicited faster pulmonary oxygen uptake (V̇o2) kinetics during moderate-intensity cycling exercise in middle-aged individuals with type 2 diabetes (T2D). This was accompanied by greater near-infrared spectroscopy-derived muscle deoxygenation (i.e., deoxygenated hemoglobin and myoglobin concentration, [HHb+Mb]) responses and a reduced Δ[HHb+Mb]-to-ΔV̇o2 ratio. This suggests that the PE-induced acceleration in oxidative metabolism in T2D is a result of greater O2 extraction and better matching between O2 delivery and utilization.
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Affiliation(s)
- Joel Rocha
- Division of Sport and Exercise Sciences, Abertay University, Dundee, United Kingdom
| | - Norita Gildea
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Donal O’Shea
- Department of Endocrinology, St. Columcille’s Hospital, Dublin, Ireland
- Department of Endocrinology and Diabetes Mellitus, St. Vincent’s University Hospital, Dublin, Ireland
| | - Simon Green
- School of Science and Health, Western Sydney University, Sydney, New South Wales, Australia
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
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26
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Gildea N, Rocha J, McDermott A, O'Shea D, Green S, Egaña M. Influence of type 2 diabetes on muscle deoxygenation during ramp incremental cycle exercise. Respir Physiol Neurobiol 2019; 269:103258. [PMID: 31349019 DOI: 10.1016/j.resp.2019.103258] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 07/04/2019] [Accepted: 07/23/2019] [Indexed: 11/18/2022]
Abstract
We tested the hypothesis that type 2 diabetes (T2D) alters the profile of muscle fractional oxygen (O2) extraction (near-infrared spectroscopy) during incremental cycle exercise. Seventeen middle-aged individuals with uncomplicated T2D and 17 controls performed an upright ramp test to exhaustion. The rate of muscle deoxygenation (i.e. deoxygenated haemoglobin and myoglobin concentration, Δ[HHb+Mb]) profiles of the vastus lateralis muscle were normalised to 100% of the response, plotted against % power output (PO) and fitted with a double linear regression model. Peak oxygen uptake was significantly (P < 0.05) reduced in individuals with T2D. The %Δ[HHb+Mb]/%PO slope of the first linear segment of the double linear regression function was significantly (P < 0.05) steeper in T2D than controls (1.59 (1.14) vs 1.23 (0.51)). Both groups displayed a near-plateau in Δ[HHb+Mb] at an exercise intensity (%PO) not different amongst them. Such findings suggest that a reduced O2 delivery to active muscles is an important underlying cause of exercise intolerance during a maximum graded test in middle-aged individuals with T2D.
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Affiliation(s)
- Norita Gildea
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Joel Rocha
- Division of Sport and Exercise Sciences, Abertay University, Dundee, UK
| | - Adam McDermott
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Donal O'Shea
- Endocrinology, St Columcille's and St Vincent's Hospitals, Dublin, Ireland
| | - Simon Green
- School of Science and Health, Western Sydney University, Sydney, Australia
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland.
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27
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Grotle AK, Crawford CK, Huo Y, Ybarbo KM, Harrison ML, Graham J, Stanhope KL, Havel PJ, Fadel PJ, Stone AJ. Exaggerated cardiovascular responses to muscle contraction and tendon stretch in UCD type-2 diabetes mellitus rats. Am J Physiol Heart Circ Physiol 2019; 317:H479-H486. [PMID: 31274351 DOI: 10.1152/ajpheart.00229.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Patients with type-2 diabetes mellitus (T2DM) have exaggerated sympathetic activity and blood pressure responses to exercise. However, the underlying mechanisms for these responses, as well as how these responses change throughout disease progression, are not completely understood. For this study, we examined the effect of the progression of T2DM on the exercise pressor reflex, a critical neurocardiovascular mechanism that functions to increase sympathetic activity and blood pressure during exercise. We also aimed to examine the effect of T2DM on reflexive cardiovascular responses to static contraction, as well as those responses to tendon stretch when an exaggerated exercise pressor reflex was present. We evoked the exercise pressor reflex and mechanoreflex by statically contracting the hindlimb muscles and stretching the Achilles tendon, respectively, for 30 s. We then compared pressor and cardioaccelerator responses in unanesthetized, decerebrated University of California Davis (UCD)-T2DM rats at 21 and 31 wk following the onset of T2DM to responses in healthy nondiabetic rats. We found that the pressor response to static contraction was greater in the 31-wk T2DM [change in mean arterial pressure (∆MAP) = 39 ± 5 mmHg] but not in the 21-wk T2DM (∆MAP = 24 ± 5 mmHg) rats compared with nondiabetic rats (∆MAP = 18 ± 2 mmHg; P < 0.05). Similarly, the pressor and the cardioaccelerator responses to tendon stretch were significantly greater in the 31-wk T2DM rats [∆MAP = 69 ± 6 mmHg; change in heart rate (∆HR) = 28 ± 4 beats/min] compared with nondiabetic rats (∆MAP = 14 ± 2 mmHg; ∆HR = 5 ± 3 beats/min; P < 0.05). These findings suggest that the exercise pressor reflex changes as T2DM progresses and that a sensitized mechanoreflex may play a role in exaggerating these cardiovascular responses.NEW & NOTEWORTHY This is the first study to provide evidence that as type-2 diabetes mellitus (T2DM) progresses, the exercise pressor reflex becomes exaggerated, an effect that may be due to a sensitized mechanoreflex. Moreover, these findings provide compelling evidence suggesting that impairments in the reflexive control of circulation contribute to exaggerated blood pressure responses to exercise in T2DM.
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Affiliation(s)
- Ann-Katrin Grotle
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Charles K Crawford
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Yu Huo
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Kai M Ybarbo
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - Michelle L Harrison
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
| | - James Graham
- Department of Molecular Biosciences School of Veterinary Medicine and Department of Nutrition; University of California Davis, Davis, California
| | - Kimber L Stanhope
- Department of Molecular Biosciences School of Veterinary Medicine and Department of Nutrition; University of California Davis, Davis, California
| | - Peter J Havel
- Department of Molecular Biosciences School of Veterinary Medicine and Department of Nutrition; University of California Davis, Davis, California
| | - Paul J Fadel
- Department of Kinesiology; The University of Texas at Arlington, Arlington, Texas
| | - Audrey J Stone
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas
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Groen MB, Knudsen TA, Finsen SH, Pedersen BK, Hellsten Y, Mortensen SP. Reduced skeletal-muscle perfusion and impaired ATP release during hypoxia and exercise in individuals with type 2 diabetes. Diabetologia 2019; 62:485-493. [PMID: 30607464 DOI: 10.1007/s00125-018-4790-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 11/08/2018] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Plasma ATP is a potent vasodilator and is thought to play a role in the local regulation of blood flow. Type 2 diabetes is associated with reduced tissue perfusion. We aimed to examine whether individuals with type 2 diabetes have reduced plasma ATP concentrations compared with healthy control participants (case-control design). METHODS We measured femoral arterial and venous plasma ATP levels with the intravascular microdialysis technique during normoxia, hypoxia and one-legged knee-extensor exercise (10 W and 30 W) in nine participants with type 2 diabetes and eight control participants. In addition, we infused acetylcholine (ACh), sodium nitroprusside (SNP) and ATP into the femoral artery to assess vascular function and ATP signalling. RESULTS Individuals with type 2 diabetes had a lower leg blood flow (LBF; 2.9 ± 0.1 l/min) compared with the control participants (3.2 ± 0.1 l/min) during exercise (p < 0.05), in parallel with lower venous plasma ATP concentration (205 ± 35 vs 431 ± 72 nmol/l; p < 0.05). During systemic hypoxia, LBF increased from 0.35 ± 0.04 to 0.54 ± 0.06 l/min in control individuals, whereas it did not increase (0.25 ± 0.04 vs 0.31 ± 0.03 l/min) in the those with type 2 diabetes and was lower than in the control individuals (p < 0.05). Hypoxia increased venous plasma ATP levels in both groups (p < 0.05), but the increase was higher in control individuals (90 ± 26 nmol/l) compared to those with type 2 diabetes (18 ± 5 nmol/l). LBF and vascular conductance were lower during ATP (0.15 and 0.4 μmol min-1 [kg leg mass]-1) and ACh (100 μg min-1 [kg leg mass]-1) infusion in individuals with type 2 diabetes compared with the control participants (p < 0.05), whereas there was no difference during SNP infusion. CONCLUSIONS/INTERPRETATION These findings demonstrate that individuals with type 2 diabetes have lower plasma ATP concentrations during exercise and hypoxia compared with control individuals, and this occurs in parallel with lower blood flow. Moreover, individuals with type 2 diabetes have a reduced vasodilatory response to infused ATP. These impairments in the ATP system are both likely to contribute to the reduced tissue perfusion associated with type 2 diabetes. TRIAL REGISTRATION ClinicalTrials.gov NCT02001766.
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Affiliation(s)
- Martin B Groen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winslowparken 21 3, 5000, Odense, Denmark
| | - Trine A Knudsen
- Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Stine H Finsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winslowparken 21 3, 5000, Odense, Denmark
| | - Bente K Pedersen
- Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Stefan P Mortensen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winslowparken 21 3, 5000, Odense, Denmark.
- Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark.
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29
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Senefeld JW, Limberg JK, Lukaszewicz KM, Hunter SK. Exercise-induced hyperemia is associated with knee extensor fatigability in adults with type 2 diabetes. J Appl Physiol (1985) 2019; 126:658-667. [PMID: 30605399 DOI: 10.1152/japplphysiol.00854.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to compare fatigability, contractile function, and blood flow to the knee extensor muscles after dynamic exercise in patients with type 2 diabetes mellitus (T2DM) and controls. The hypotheses were that patients with T2DM would demonstrate greater fatigability than controls, and greater fatigability would be associated with a lower exercise-induced increase in blood flow and greater impairments in contractile function. Patients with T2DM ( n = 15; 8 men; 62.4 ± 9.0 yr; 30.4 ± 7.7 kg/m2; 7,144 ± 3,294 steps/day) and 15 healthy control subjects (8 men, 58.4 ± 6.9 yr; 28.4 ± 4.6 kg/m2; 7,893 ± 2,323 steps/day) were matched for age, sex, body mass index, and physical activity. Fatigability was quantified as the reduction in knee extensor power during a 6-min dynamic exercise. Before and after exercise, vascular ultrasonography and electrical stimulation were used to assess skeletal muscle blood flow and contractile properties, respectively. Patients with T2DM had greater fatigability (30.0 ± 20.1% vs. 14.6 ± 19.0%, P < 0.001) and lower exercise-induced hyperemia (177 ± 90% vs. 194 ± 79%, P = 0.04) than controls but similar reductions in the electrically evoked twitch amplitude (37.6 ± 24.8% vs. 31.6 ± 30.1%, P = 0.98). Greater fatigability of the knee extensor muscles was associated with postexercise reductions in twitch amplitude ( r = 0.64, P = 0.001) and lesser exercise-induced hyperemia ( r = -0.56, P = 0.009). Patients with T2DM had greater lower-limb fatigability during dynamic exercise, which was associated with reduced contractile function and lower skeletal muscle blood flow. Thus, treatments focused on enhancing perfusion and reversing impairments in contractile function in patients with T2DM may offset lower-limb fatigability and aid in increasing exercise capacity. NEW & NOTEWORTHY Although prior studies compare patients with type 2 diabetes mellitus (T2DM) with lean controls, our study includes controls matched for age, body mass, and physical activity to more closely assess the effects of T2DM. Patients with T2DM demonstrated no impairment in macrovascular endothelial function, evidenced by similar flow-mediated dilation to controls. However, patients with T2DM had greater fatigability and reduced exercise-induced increase in blood flow (hyperemia) after a lower-limb dynamic fatiguing exercise compared with controls.
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Affiliation(s)
- Jonathon W Senefeld
- Clinical and Translational Rehabilitation Health Sciences Program, Marquette University , Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Jacqueline K Limberg
- Department of Nutrition and Exercise Physiology, University of Missouri , Columbia, Missouri
| | - Kathleen M Lukaszewicz
- Clinical and Translational Rehabilitation Health Sciences Program, Marquette University , Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
| | - Sandra K Hunter
- Clinical and Translational Rehabilitation Health Sciences Program, Marquette University , Milwaukee, Wisconsin.,Department of Physical Therapy, Marquette University , Milwaukee, Wisconsin
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Senefeld J, Magill SB, Harkins A, Harmer AR, Hunter SK. Mechanisms for the increased fatigability of the lower limb in people with type 2 diabetes. J Appl Physiol (1985) 2018; 125:553-566. [DOI: 10.1152/japplphysiol.00160.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Fatiguing exercise is the basis of exercise training and a cornerstone of management of type 2 diabetes mellitus (T2D); however, little is known about the fatigability of limb muscles and the involved mechanisms in people with T2D. The purpose of this study was to compare fatigability of knee extensor muscles between people with T2D and controls without diabetes and determine the neural and muscular mechanisms for a dynamic fatiguing task. Seventeen people with T2D [ten men and seven women: 59.6 (9.0) yr] and twenty-one age-, body mass index-, and physical activity-matched controls [eleven men and ten women: 59.5 (9.6) yr] performed one hundred twenty high-velocity concentric contractions (one contraction/3 s) with a load equivalent to 20% maximal voluntary isometric contraction (MVIC) torque with the knee extensors. Transcranial magnetic stimulation (TMS) and electrical stimulation of the quadriceps were used to assess voluntary activation and contractile properties. People with T2D had larger reductions than controls in power during the fatiguing task [42.8 (24.2) vs. 26.4 (15.0)%; P < 0.001] and MVIC torque after the fatiguing task [37.6 (18.2) vs. 26.4 (12.1)%; P = 0.04]. People with T2D had greater reductions than controls in the electrically evoked twitch amplitude after the fatiguing task [44.0 (20.4) vs. 35.4 (12.1)%, respectively; P = 0.01]. However, the decrease in voluntary activation was similar between groups when assessed with electrical stimulation [12.1 (2.6) vs. 12.4 (4.4)% decrease; P = 0.84] and TMS ( P = 0.995). A greater decline in MVIC torque was associated with larger reductions of twitch amplitude ( r2 = 0.364, P = 0.002). Although neural mechanisms contributed to fatigability, contractile mechanisms were responsible for the greater knee extensor fatigability in men and women with T2D compared with healthy controls. NEW & NOTEWORTHY Transcranial magnetic stimulation and percutaneous muscle stimulation were used to determine the contributions of neural and contractile mechanisms of fatigability of the knee extensor muscles after a dynamic fatiguing task in men and women with type 2 diabetes (T2D) and healthy age-, body mass index-, and physical activity-matched controls. Although neural and contractile mechanisms contributed to greater fatigability of people with T2D, fatigability was primarily associated with impaired contractile mechanisms and glycemic control.
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Affiliation(s)
- Jonathon Senefeld
- Program in Exercise Science, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin
| | - Steven B. Magill
- Division of Endocrinology, Metabolism, and Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - April Harkins
- Department of Clinical Laboratory Science, Marquette University, Milwaukee, Wisconsin
| | - Alison R. Harmer
- Musculoskeletal Health Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia
| | - Sandra K. Hunter
- Program in Exercise Science, Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin
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31
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Poitras VJ, Hudson RW, Tschakovsky ME. Exercise intolerance in Type 2 diabetes: is there a cardiovascular contribution? J Appl Physiol (1985) 2018; 124:1117-1139. [PMID: 29420147 DOI: 10.1152/japplphysiol.00070.2017] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Physical activity is critically important for Type 2 diabetes management, yet adherence levels are poor. This might be partly due to disproportionate exercise intolerance. Submaximal exercise tolerance is highly sensitive to muscle oxygenation; impairments in exercising muscle oxygen delivery may contribute to exercise intolerance in Type 2 diabetes since there is considerable evidence for the existence of both cardiac and peripheral vascular dysfunction. While uncompromised cardiac output during submaximal exercise is consistently observed in Type 2 diabetes, it remains to be determined whether an elevated cardiac sympathetic afferent reflex could sympathetically restrain exercising muscle blood flow. Furthermore, while deficits in endothelial function are common in Type 2 diabetes and are often cited as impairing exercising muscle oxygen delivery, no direct evidence in exercise exists, and there are several other vasoregulatory mechanisms whose dysfunction could contribute. Finally, while there are findings of impaired oxygen delivery, conflicting evidence also exists. A definitive conclusion that Type 2 diabetes compromises exercising muscle oxygen delivery remains premature. We review these potentially dysfunctional mechanisms in terms of how they could impair oxygen delivery in exercise, evaluate the current literature on whether an oxygen delivery deficit is actually manifest, and correspondingly identify key directions for future research.
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Affiliation(s)
- Veronica J Poitras
- School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada.,Department of Physiology, Queen's University , Kingston, Ontario , Canada.,Children's Hospital of Eastern Ontario, Research Institute , Ottawa, Ontario , Canada
| | - Robert W Hudson
- Department of Medicine, Division of Endocrinology, Queen's University , Kingston, Ontario , Canada
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University , Kingston, Ontario , Canada
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Caron J, duManoir GR, Labrecque L, Chouinard A, Ferland A, Poirier P, Legault S, Brassard P. Impact of type 2 diabetes on cardiorespiratory function and exercise performance. Physiol Rep 2017; 5:5/4/e13145. [PMID: 28242825 PMCID: PMC5328776 DOI: 10.14814/phy2.13145] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 12/30/2016] [Indexed: 01/07/2023] Open
Abstract
The aim of this study was to examine the impact of well‐controlled uncomplicated type 2 diabetes (T2D) on exercise performance. Ten obese sedentary men with T2D and nine control participants without diabetes matched for age, sex, and body mass index were recruited. Anthropometric characteristics, blood samples, resting cardiac, and pulmonary functions and maximal oxygen uptake (VO2max) and ventilatory threshold were measured on a first visit. On the four subsequent visits, participants (diabetics: n = 6; controls: n = 7) performed step transitions (6 min) of moderate‐intensity exercise on an upright cycle ergometer from unloaded pedaling to 80% of ventilatory threshold. VO2 (τVO2) and HR (τHR) kinetics were characterized with a mono‐exponential model. VO2max (27.0 ± 3.4 vs. 26.7 ± 5.0 mL kg−1 min−1; P = 0.85), τVO2 (43 ± 6 vs. 43 ± 10 sec; P = 0.73), and τHR (42 ± 17 vs. 43 ± 13 sec; P = 0.94) were similar between diabetics and controls respectively. The remaining variables were also similar between groups, with the exception of lower maximal systolic blood pressure in diabetics (P = 0.047). These results suggest that well‐controlled T2D is not associated with a reduction in VO2max or slower τVO2 and τHR.
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Affiliation(s)
- Joanie Caron
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Québec, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada
| | - Gregory R duManoir
- School of Health & Exercise Sciences, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Québec, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada
| | - Audrey Chouinard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Québec, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada
| | - Annie Ferland
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada
| | - Paul Poirier
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada.,Faculty of Pharmacy, Université Laval, Québec, Québec, Canada
| | - Sylvie Legault
- Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Québec, Canada .,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Québec, Québec, Canada
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33
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Impaired Tissue Oxygenation in Metabolic Syndrome Requires Increased Microvascular Perfusion Heterogeneity. J Cardiovasc Transl Res 2017; 10:69-81. [PMID: 28168652 DOI: 10.1007/s12265-017-9732-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/25/2017] [Indexed: 01/09/2023]
Abstract
Metabolic syndrome (MS) in obese Zucker rats (OZR) is associated with impaired skeletal muscle performance and blunted hyperemia. Studies suggest that reduced O2 diffusion capacity is required to explain compromised muscle performance and that heterogeneous microvascular perfusion distribution is critical. We modeled tissue oxygenation during muscle contraction in control and OZR skeletal muscle using physiologically realistic relationships. Using a network model of Krogh cylinders with increasing perfusion asymmetry and increased plasma skimming, we predict increased perfusion heterogeneity and decreased muscle oxygenation in OZR, with partial recovery following therapy. Notably, increasing O2 delivery had less impact on VO2 than equivalent decreases in O2 delivery, providing a mechanism for previous empirical work associating perfusion heterogeneity and impaired O2 extraction. We demonstrate that increased skeletal muscle perfusion asymmetry is a defining characteristic of MS and must be considered to effectively model and understand blood-tissue O2 exchange in this model of human disease.
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Leone RJ, Lalande S. Intermittent hypoxia as a means to improve aerobic capacity in type 2 diabetes. Med Hypotheses 2017; 100:59-63. [PMID: 28236850 DOI: 10.1016/j.mehy.2017.01.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/15/2016] [Accepted: 01/21/2017] [Indexed: 11/18/2022]
Abstract
Physical inactivity and a low maximal aerobic capacity (VO2max) strongly predict morbidity and mortality in patients with type 2 diabetes (T2D). Patients with T2D have a reduced VO2max when compared with healthy individuals of similar age, weight, and physical activity levels, and this lower aerobic capacity is usually attributed to a reduced oxygen delivery to the working muscles. The oxygen carrying capacity of the blood, as well as increases in cardiac output and blood flow, contribute to the delivery of oxygen to the active muscles during exercise. Hemoglobin mass (Hb mass), a key determinant of oxygen carrying capacity, is suggested to be reduced in patients with T2D following the observation of a lower blood volume (BV) in combination with normal hematocrit levels in this population. Therefore, a lower Hb mass, in addition to a reported lower BV and impaired cardiovascular response to exercise, likely contributes to the reduced oxygen delivery and VO2max in patients with T2D. While exercise training increases Hb mass, BV, and consequently VO2max, the majority of patients with T2D are not physically active, highlighting the need for alternative methods to improve VO2max in this population. Exposure to hypoxia triggers the release of erythropoietin, the hormone regulating red blood cell production, which increases Hb mass and consequently BV. Exposure to mild intermittent hypoxia (IH), characterized by few and short episodes of hypoxia at a fraction of inspired oxygen ranging between 10 and 14% interspersed with cycles of normoxia, increased red blood cell volume, Hb mass, and plasma volume in patients with coronary artery disease or chronic obstructive pulmonary disease, which resulted in an improved VO2max in both populations. We hypothesize that 12 exposures to mild IH over a period of 4weeks will increase Hb mass, BV, cardiac function, and VO2max in patients with T2D. Therefore, exposures to mild IH may increase oxygen delivery and VO2max without the need to perform exercise in patients with T2D.
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Affiliation(s)
- R J Leone
- School of Exercise and Rehabilitation Sciences, College of Health and Human Services, University of Toledo, Toledo, OH, USA.
| | - S Lalande
- School of Exercise and Rehabilitation Sciences, College of Health and Human Services, University of Toledo, Toledo, OH, USA
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35
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Miyamoto T, Kamada H, Tamaki A, Moritani T. Low-intensity electrical muscle stimulation induces significant increases in muscle strength and cardiorespiratory fitness. Eur J Sport Sci 2016; 16:1104-10. [DOI: 10.1080/17461391.2016.1151944] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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36
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Response to Exercise Training and Outcomes in Patients With Heart Failure and Diabetes Mellitus: Insights From the HF-ACTION Trial. J Card Fail 2015; 22:485-91. [PMID: 26687984 DOI: 10.1016/j.cardfail.2015.12.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 11/25/2015] [Accepted: 12/01/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND In HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training), exercise training improved functional capacity in heart failure with reduced ejection fraction (HFrEF). Previous studies have suggested that diabetes mellitus (DM) may be associated with an attenuated response to exercise. We explored whether DM attenuated the improvement in functional capacity with exercise. METHODS AND RESULTS HF-ACTION randomized 2331 patients with HFrEF to medical therapy with or without exercise training over a median follow-up of 2.5 years. We examined the interaction between DM and exercise response measured by change in 6-minute walk distance (6MWD) and peak VO2. We also examined outcomes by DM status. In HF-ACTION, 748 (32%) patients had DM. DM patients had lower functional capacity at baseline and had lower exercise volumes at 3 months. There was a significant interaction between DM status and exercise training for change in peak VO2 (interaction P = .02), but not 6MWD. In the exercise arm, DM patients had a smaller mean increase in peak VO2 than non-DM patients (P = .03). There was no interaction between DM and exercise on clinical outcomes. After risk adjustment, DM was associated with increased all-cause mortality/hospitalization (P = .03). CONCLUSIONS In HF-ACTION, DM was associated with lower baseline functional capacity, an attenuated improvement in peak VO2, and increased hospitalizations.
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Nyberg M, Gliemann L, Hellsten Y. Vascular function in health, hypertension, and diabetes: effect of physical activity on skeletal muscle microcirculation. Scand J Med Sci Sports 2015; 25 Suppl 4:60-73. [DOI: 10.1111/sms.12591] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2015] [Indexed: 12/31/2022]
Affiliation(s)
- M. Nyberg
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - L. Gliemann
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
| | - Y. Hellsten
- Department of Nutrition, Exercise and Sports; University of Copenhagen; Copenhagen Denmark
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38
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Laughlin MH. Physical activity-induced remodeling of vasculature in skeletal muscle: role in treatment of type 2 diabetes. J Appl Physiol (1985) 2015; 120:1-16. [PMID: 26472876 DOI: 10.1152/japplphysiol.00789.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/08/2015] [Indexed: 01/15/2023] Open
Abstract
This manuscript summarizes and discusses adaptations of skeletal muscle vasculature induced by physical activity and applies this understanding to benefits of exercise in prevention and treatment of type 2 diabetes (T2D). Arteriolar trees of skeletal muscle are heterogeneous. Exercise training increases capillary exchange and blood flow capacities. The distribution of vascular adaptation to different types of exercise training are influenced by muscle fiber type composition and fiber recruitment patterns that produce different modes of exercise. Thus training-induced adaptations in vascular structure and vascular control in skeletal muscle are not homogeneously distributed throughout skeletal muscle or along the arteriolar tree within a muscle. Results summarized indicate that similar principles apply to vascular adaptation in skeletal muscle in T2D. It is concluded that exercise training-induced changes in vascular gene expression differ along the arteriolar tree and by skeletal muscle fiber type composition. Results suggest that it is unlikely that hemodynamic forces are the only exercise-induced signals mediating the regulation of vascular gene expression. In patients with T2D, exercise training is perhaps the most effective treatment of the many related symptoms. Training-induced changes in the vasculature and in insulin signaling in the muscle fibers and vasculature augment glucose and insulin delivery as well as glucose uptake. If these adaptations occur in a sufficient amount of muscle mass, exposure to hyperglycemia and hyperinsulinemia will decrease along with the risk of microvascular complications throughout the body. It is postulated that exercise sessions in programs of sufficient duration, that engage as much skeletal muscle mass as possible, and that recruit as many muscle fibers within each muscle as possible will produce the greatest benefit. The added benefit of combined resistance and aerobic training programs and of high-intensity exercise programs is not simply "more exercise is better".
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Affiliation(s)
- M Harold Laughlin
- Department of Biomedical Sciences, Department of Medical Pharmacology & Physiology, and Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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39
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Yamakoshi K, Yagishita K, Tsuchimochi H, Inagaki T, Shirai M, Poole DC, Kano Y. Microvascular oxygen partial pressure during hyperbaric oxygen in diabetic rat skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2015; 309:R1512-20. [PMID: 26468263 DOI: 10.1152/ajpregu.00380.2015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/10/2015] [Indexed: 11/22/2022]
Abstract
Hyperbaric oxygen (HBO) is a major therapeutic treatment for ischemic ulcerations that perforate skin and underlying muscle in diabetic patients. These lesions do not heal effectively, in part, because of the hypoxic microvascular O2 partial pressures (PmvO2 ) resulting from diabetes-induced cardiovascular dysfunction, which alters the dynamic balance between O2 delivery (Q̇o2) and utilization (V̇o2) rates. We tested the hypothesis that HBO in diabetic muscle would exacerbate the hyperoxic PmvO2 dynamics due, in part, to a reduction or slowing of the cardiovascular, sympathetic nervous, and respiratory system responses to acute HBO exposure. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (control) groups. A small animal hyperbaric chamber was pressurized with oxygen (100% O2) to 3.0 atmospheres absolute (ATA) at 0.2 ATA/min. Phosphorescence quenching techniques were used to measure PmvO2 in tibialis anterior muscle of anesthetized rats during HBO. Lumbar sympathetic nerve activity (LSNA), heart rate (HR), and respiratory rate (RR) were measured electrophysiologically. During the normobaric hyperoxia and HBO, DIA tibialis anterior PmvO2 increased faster (mean response time, CONT 78 ± 8, DIA 55 ± 8 s, P < 0.05) than CONT. Subsequently, PmvO2 remained elevated at similar levels in CONT and DIA muscles until normobaric normoxic recovery where the DIA PmvO2 retained its hyperoxic level longer than CONT. Sympathetic nervous system and cardiac and respiratory responses to HBO were slower in DIA vs. CONT. Specifically the mean response times for RR (CONT: 6 ± 1 s, DIA: 29 ± 4 s, P < 0.05), HR (CONT: 16 ± 1 s, DIA: 45 ± 5 s, P < 0.05), and LSNA (CONT: 140 ± 16 s, DIA: 247 ± 34 s, P < 0.05) were greater following HBO onset in DIA than CONT. HBO treatment increases tibialis anterior muscle PmvO2 more rapidly and for a longer duration in DIA than CONT, but not to a greater level. Whereas respiratory, cardiovascular, and LSNA responses to HBO are profoundly slowed in DIA, only the cardiovascular arm (via HR) may contribute to the muscle vascular incompetence and these faster PmvO2 kinetics.
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Affiliation(s)
- Kohei Yamakoshi
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Tokyo, Japan
| | - Kazuyoshi Yagishita
- Clinical Center for Sports Medicine and Sports Dentistry, Hyperbaric Medical Center/Sports Medicine Clinical Center, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - Tadakatsu Inagaki
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; and
| | - David C Poole
- Departments of Anatomy & Physiology and Kinesiology, Kansas State University, Manhattan, Kansas
| | - Yutaka Kano
- Department of Engineering Science, Bioscience and Technology Program, University of Electro-Communications, Tokyo, Japan;
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Olver TD, Laughlin MH. Endurance, interval sprint, and resistance exercise training: impact on microvascular dysfunction in type 2 diabetes. Am J Physiol Heart Circ Physiol 2015; 310:H337-50. [PMID: 26408541 DOI: 10.1152/ajpheart.00440.2015] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 09/16/2015] [Indexed: 01/02/2023]
Abstract
Type 2 diabetes (T2D) alters capillary hemodynamics, causes capillary rarefaction in skeletal muscle, and alters endothelial and vascular smooth muscle cell phenotype, resulting in impaired vasodilatory responses. These changes contribute to altered blood flow responses to physiological stimuli, such as exercise and insulin secretion. T2D-induced microvascular dysfunction impairs glucose and insulin delivery to skeletal muscle (and other tissues such as skin and nervous), thereby reducing glucose uptake and perpetuating hyperglycemia and hyperinsulinemia. In patients with T2D, exercise training (EX) improves microvascular vasodilator and insulin signaling and attenuates capillary rarefaction in skeletal muscle. EX-induced changes subsequently augment glucose and insulin delivery as well as glucose uptake. If these adaptions occur in a sufficient amount of tissue, and skeletal muscle in particular, chronic exposure to hyperglycemia and hyperinsulinemia and the risk of microvascular complications in all vascular beds will decrease. We postulate that EX programs that engage as much skeletal muscle mass as possible and recruit as many muscle fibers within each muscle as possible will generate the greatest improvements in microvascular function, providing that the duration of the stimulus is sufficient. Primary improvements in microvascular function occur in tissues (skeletal muscle primarily) engaged during exercise, and secondary improvements in microvascular function throughout the body may result from improved blood glucose control. We propose that the added benefit of combined resistance and aerobic EX programs and of vigorous intensity EX programs is not simply "more is better." Rather, we believe the additional benefit is the result of EX-induced adaptations in and around more muscle fibers, resulting in more muscle mass and the associated microvasculature being changed. Thus, to acquire primary and secondary improvements in microvascular function and improved blood glucose control, EX programs should involve upper and lower body exercise and modulate intensity to augment skeletal muscle fiber recruitment. Under conditions of limited mobility, it may be necessary to train skeletal muscle groups separately to maximize whole body skeletal muscle fiber recruitment.
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Affiliation(s)
- T Dylan Olver
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri;
| | - M Harold Laughlin
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri
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Poitras VJ, Bentley RF, Hopkins-Rosseel DH, LaHaye SA, Tschakovsky ME. Lack of independent effect of type 2 diabetes beyond characteristic comorbidities and medications on small muscle mass exercising muscle blood flow and exercise tolerance. Physiol Rep 2015; 3:3/8/e12487. [PMID: 26265750 PMCID: PMC4562573 DOI: 10.14814/phy2.12487] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Persons with type 2 diabetes (T2D) are believed to have reduced exercise tolerance; this may be partly due to impaired exercising muscle blood flow (MBF). Whether there is an impact of T2D on exercising MBF within the typical constellation of comorbidities (hypertension, dyslipidemia, obesity) and their associated medications has not been investigated. We tested the hypothesis that small muscle mass exercise tolerance is reduced in persons with T2D versus Controls (matched for age, body mass index, fitness, comorbidities, non-T2D medications) and that this is related to blunted MBF. Eight persons with T2D and eight controls completed a forearm critical force (fCFimpulse) test as a measure of exercise tolerance (10-min intermittent maximal effort forearm contractions; the average contraction impulse in the last 30 sec quantified fCFimpulse). Forearm blood flow (FBF; ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured; forearm vascular conductance (FVK) was calculated. Data are means ± SD, T2D versus Control. fCFimpulse was not different between groups (136.9 ± 47.3 N·sec vs. 163.1 ± 49.7 N·sec, P = 0.371) nor was the ΔFBF from rest to during exercise at fCFimpulse (502.9 ± 144.6 vs. 709.1 ± 289.2 mL/min, P = 0.092), or its determinants ΔFVK and ΔMAP (both P > 0.05), although there was considerable interindividual variability. ΔFBF was strongly related to fCFimpulse (r = 0.727, P = 0.002), providing support for the relationship between oxygen delivery and exercise tolerance. We conclude that small muscle mass exercising MBF and exercise tolerance are not impaired in representative persons with T2D versus appropriately matched controls. This suggests that peripheral vascular control impairment does not contribute to reduced exercise tolerance in this population.
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Affiliation(s)
- Veronica J Poitras
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Robert F Bentley
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Diana H Hopkins-Rosseel
- Cardiac Rehabilitation Centre, Hotel Dieu Hospital, Kingston, Ontario, Canada School of Rehabilitation Therapy, Queen's University, Kingston, Ontario, Canada
| | - Stephen A LaHaye
- Cardiac Rehabilitation Centre, Hotel Dieu Hospital, Kingston, Ontario, Canada
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
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Kiely C, Rocha J, O'Connor E, O'Shea D, Green S, Egaña M. Influence of menopause and Type 2 diabetes on pulmonary oxygen uptake kinetics and peak exercise performance during cycling. Am J Physiol Regul Integr Comp Physiol 2015; 309:R875-83. [PMID: 26269520 DOI: 10.1152/ajpregu.00258.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 08/11/2015] [Indexed: 02/02/2023]
Abstract
We investigated if the magnitude of the Type 2 diabetes (T2D)-induced impairments in peak oxygen uptake (V̇O2) and V̇O2 kinetics was affected by menopausal status. Twenty-two women with T2D (8 premenopausal, 14 postmenopausal), and 22 nondiabetic (ND) women (11 premenopausal, 11 postmenopausal) matched by age (range = 30-59 yr) were recruited. Participants completed four bouts of constant-load cycling at 80% of their ventilatory threshold for the determination of V̇O2 kinetics. Cardiac output (CO) (inert gas rebreathing) was recorded at rest and at 30 s and 240 s during two additional bouts. Peak V̇O2 was significantly (P < 0.05) reduced in both groups with T2D compared with ND counterparts (premenopausal, 1.79 ± 0.16 vs. 1.55 ± 0.32 l/min; postmenopausal, 1.60 ± 0.30 vs. 1.45 ± 0.24 l/min). The time constant of phase II of the V̇O2 response was slowed (P < 0.05) in both groups with T2D compared with healthy counterparts (premenopausal, 29.1 ± 11.2 vs. 43.0 ± 12.2 s; postmenopausal, 33.0 ± 9.1 vs. 41.8 ± 17.7 s). At rest and during submaximal exercise absolute CO responses were lower, but the "gains" in CO larger (both P < 0.05) in both groups with T2D. Our results suggest that the magnitude of T2D-induced impairments in peak V̇O2 and V̇O2 kinetics is not affected by menopausal status in participants younger than 60 yr of age.
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Affiliation(s)
- Catherine Kiely
- School of Medicine, Department of Physiology, Trinity College Dublin, Dublin, Ireland
| | - Joel Rocha
- School of Medicine, Department of Physiology, Trinity College Dublin, Dublin, Ireland
| | - Eamonn O'Connor
- School of Medicine, Department of Physiology, Trinity College Dublin, Dublin, Ireland
| | - Donal O'Shea
- Endocrinology, St. Columcille's and St. Vincent's Hospitals, Dublin, Ireland; and
| | - Simon Green
- School of Science and Health and School of Medicine, University of Western Sydney, Sydney, Australia
| | - Mikel Egaña
- School of Medicine, Department of Physiology, Trinity College Dublin, Dublin, Ireland;
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Laughlin MH, Padilla J, Jenkins NT, Thorne PK, Martin JS, Rector RS, Akter S, Davis JW. Exercise training causes differential changes in gene expression in diaphragm arteries and 2A arterioles of obese rats. J Appl Physiol (1985) 2015; 119:604-16. [PMID: 26183478 DOI: 10.1152/japplphysiol.00317.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/10/2015] [Indexed: 12/20/2022] Open
Abstract
We employed next-generation, transcriptome-wide RNA sequencing (RNA-Seq) technology to assess the effects of two different exercise training protocols on transcriptional profiles in diaphragm second-order arterioles (D2a) and in the diaphragm feed artery (DFA) from Otsuka Long Evans Tokushima Fatty (OLETF) rats. Arterioles were isolated from the diaphragm of OLETF rats that underwent an endurance exercise training program (EX; n = 13), interval sprint training program (SPRINT; n = 14), or remained sedentary (Sed; n = 12). Our hypothesis was that exercise training would have similar effects on gene expression in the diaphragm and soleus muscle arterioles because diaphragm blood flow increases during exercise to a similar extent as in soleus. Results reveal that several canonical pathways that were significantly altered by exercise in limb skeletal muscles were not among the pathways significantly changed in the diaphragm arterioles including actin cytoskeleton signaling, role of NFAT in regulation of immune response, protein kinase A signaling, and protein ubiquitination pathway. EX training altered the expression of a smaller number of genes than did SPRINT in the DFA but induced a larger number of genes with altered expression in the D2a than did SPRINT. In fact, FDR differential expression analysis (FDR, 10%) indicated that only two genes exhibited altered expression in D2a of SPRINT rats. Very few of the genes that exhibited altered expression in the DFA or D2a were also altered in limb muscle arterioles. Finally, results indicate that the 2a arterioles of soleus muscle (S2a) from endurance-trained animals and the DFA of SPRINT animals exhibited the largest number of genes with altered expression.
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Affiliation(s)
- M Harold Laughlin
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Biomedical Sciences, University of Missouri, Columbia, Missouri; Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Jaume Padilla
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | | | - Pamela K Thorne
- Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Jeffrey S Martin
- Cell Biology and Physiology, Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, Alabama; Kinesiology, Auburn University, Auburn, Alabama
| | - R Scott Rector
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Research Service-Harry S Truman Memorial VA Medical Center, Columbia, Missouri; Internal Medicine-Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri
| | - Sadia Akter
- MU Informatics Institute, University of Missouri, Columbia, Missouri; and
| | - J Wade Davis
- Health Management and Informatics, University of Missouri, Columbia, Missouri; Statistics, University of Missouri, Columbia, Missouri; MU Informatics Institute, University of Missouri, Columbia, Missouri; and
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Laughlin MH, Padilla J, Jenkins NT, Thorne PK, Martin JS, Rector RS, Akter S, Davis JW. Exercise-induced differential changes in gene expression among arterioles of skeletal muscles of obese rats. J Appl Physiol (1985) 2015; 119:583-603. [PMID: 26183477 DOI: 10.1152/japplphysiol.00316.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/10/2015] [Indexed: 02/01/2023] Open
Abstract
Using next-generation, transcriptome-wide RNA sequencing (RNA-Seq) technology we assessed the effects of exercise training on transcriptional profiles in skeletal muscle arterioles isolated from the soleus and gastrocnemius muscles of Otsuka Long Evans Tokushima Fatty (OLETF) rats that underwent an endurance exercise training program (EX; n = 13), interval sprint training program (SPRINT; n = 14), or remained sedentary (Sed; n = 12). We hypothesized that the greatest effects of exercise would be in the gastrocnemius arterioles. Results show that EX caused the largest number of changes in gene expression in the soleus and white gastrocnemius 2a arterioles with little to no changes in the feed arteries. In contrast, SPRINT caused substantial changes in gene expression in the feed arteries. IPA canonical pathway analysis revealed 18 pathways with significant changes in gene expression when analyzed across vessels and revealed that EX induces increased expression of the following genes in all arterioles examined: Shc1, desert hedgehog protein (Dhh), adenylate cyclase 4 (Adcy4), G protein binding protein, alpha (Gnat1), and Bcl2l1 and decreased expression of ubiquitin D (Ubd) and cAMP response element modulator (Crem). EX increased expression of endothelin converting enzyme (Ece1), Hsp90b, Fkbp5, and Cdcl4b in four of five arterioles. SPRINT had effects on expression of Crem, Dhh, Bcl2l1, and Ubd that were similar to EX. SPRINT also increased expression of Nfkbia, Hspa5, Tubb 2a and Tubb 2b, and Fkbp5 in all five arterioles and increased expression of Gnat1 in all but the soleus second-order arterioles. Many contractile and/or structural protein genes were increased by SPRINT in the gastrocnemius feed artery, but the same genes exhibited decreased expression in red gastrocnemius arterioles. We conclude that training-induced changes in arteriolar gene expression patterns differ by muscle fiber type composition and along the arteriolar tree.
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Affiliation(s)
- M Harold Laughlin
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; Biomedical Sciences, University of Missouri, Columbia, Missouri; Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Jaume Padilla
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Child Health, University of Missouri, Columbia, Missouri; Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | | | - Pamela K Thorne
- Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Jeffrey S Martin
- Cell Biology and Physiology, Edward Via College of Osteopathic Medicine-Auburn Campus, Auburn, Alabama; Kinesiology, Auburn University, Auburn, Alabama
| | - R Scott Rector
- Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri; Research Service-Harry S Truman Memorial Veterans Affairs Medical Center, Columbia, Missouri; Medicine-Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri
| | - Sadia Akter
- Statistics, University of Missouri, Columbia, Missouri
| | - J Wade Davis
- Health Management and Informatics, University of Missouri, Columbia, Missouri; Statistics, University of Missouri, Columbia, Missouri; MU Informatics Institute, University of Missouri, Columbia, Missouri; and
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Poitras VJ, Bentley RF, Hopkins-Rosseel DH, LaHaye SA, Tschakovsky ME. Independent effect of type 2 diabetes beyond characteristic comorbidities and medications on immediate but not continued knee extensor exercise hyperemia. J Appl Physiol (1985) 2015; 119:202-12. [PMID: 26048976 DOI: 10.1152/japplphysiol.00758.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 06/01/2015] [Indexed: 01/23/2023] Open
Abstract
We tested the hypothesis that type 2 diabetes (T2D), when present in the characteristic constellation of comorbidities (obesity, hypertension, dyslipidemia) and medications, slows the dynamic adjustment of exercising muscle perfusion and blunts the steady state relative to that of controls matched for age, body mass index, fitness, comorbidities, and non-T2D medications. Thirteen persons with T2D and 11 who served as controls performed rhythmic single-leg isometric quadriceps exercise (rest-to-6 kg and 6-to-12 kg transitions, 5 min at each intensity). Measurements included leg blood flow (LBF, femoral artery ultrasound), mean arterial pressure (MAP, finger photoplethysmography), and leg vascular conductance (LVK, calculated). Dynamics were quantified using mean response time (MRT). Measures of amplitude were also used to compare response adjustment: the change from baseline to 1) the peak initial response (greatest 1-s average in the first 10 s; ΔLBFPIR, ΔLVKPIR) and 2) the on-transient (average from curve fit at 15, 45, and 75 s; ΔLBFON, ΔLVKON). ΔLBFPIR was significantly blunted in T2D vs. control individuals (P = 0.037); this was due to a tendency for reduced ΔLVKPIR (P = 0.063). In contrast, the overall response speed was not different between groups (MRT P = 0.856, ΔLBFON P = 0.150) nor was the change from baseline to steady state (P = 0.204). ΔLBFPIR, ΔLBFON, and LBF MRT did not differ between rest-to-6 kg and 6-to-12 kg workload transitions (all P > 0.05). Despite a transient amplitude impairment at the onset of exercise, there is no robust or consistent effect of T2D on top of the comorbidities and medications typical of this population on the overall dynamic adjustment of LBF, or the steady-state levels achieved during low- or moderate-intensity exercise.
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Affiliation(s)
- Veronica J Poitras
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Robert F Bentley
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Diana H Hopkins-Rosseel
- Cardiac Rehabilitation Centre, Hotel Dieu Hospital, Kingston, Ontario, Canada; and School of Rehabilitation Therapy, Queen's University, Kingston, Ontario, Canada
| | - Stephen A LaHaye
- Cardiac Rehabilitation Centre, Hotel Dieu Hospital, Kingston, Ontario, Canada; and
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada;
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O'Connor E, Green S, Kiely C, O'Shea D, Egaña M. Differential effects of age and type 2 diabetes on dynamic vs. peak response of pulmonary oxygen uptake during exercise. J Appl Physiol (1985) 2015; 118:1031-9. [PMID: 25701005 DOI: 10.1152/japplphysiol.01040.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 02/18/2015] [Indexed: 11/22/2022] Open
Abstract
We investigated if the magnitude of the type 2 diabetes (T2D)-induced impairments in peak oxygen uptake (V̇o2) and V̇o2 kinetics was affected by age. Thirty-three men with T2D (15 middle-aged, 18 older), and 21 nondiabetic (ND) men (11 middle-aged, 10 older) matched by age were recruited. Participants completed four 6-min bouts of constant-load cycling at 80% ventilatory threshold for the determination of V̇o2 kinetics. Cardiac output (inert-gas rebreathing) was recorded at rest and 30 and 240 s during two additional bouts. Peak V̇o2 (determined from a separate graded test) was significantly (P < 0.05) reduced in middle-aged and older men with T2D compared with their respective ND counterparts (middle-aged, 3.2 ± 0.5 vs. 2.5 ± 0.5 l/min; older, 2.7 ± 0.4 vs. 2.4 ± 0.4 l/min), and the magnitude of these impairments was not affected by age. However, the time constant of phase II of the V̇o2 response was only slowed (P < 0.05) in middle-aged men with T2D compared with healthy counterparts, whereas it was similar among older men with and without T2D (middle-aged, 26.8 ± 9.3 vs. 41.6 ± 12.1 s; older, 40.5 ± 7.8 vs. 41.1 ± 8.5 s). Similarly, the "gains" in systemic vascular conductance (estimated from the slope between cardiac output and mean arterial pressure responses) were lower (P < 0.05) in middle-aged men with T2D than ND controls, but similar between the older groups. The results suggest that the mechanisms by which T2D induces significant reductions in peak exercise performance are linked to a slower dynamic response of V̇o2 and reduced systemic vascular conductance responses in middle-aged men, whereas this is not the case in older men.
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Affiliation(s)
- Eamonn O'Connor
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Simon Green
- School of Science and Health and School of Medicine, University of Western Sydney, Sydney, New South Wales, Australia
| | - Catherine Kiely
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Donal O'Shea
- Endocrinology, St. Columcille's and St. Vincent's Hospitals, Dublin, Ireland; and
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland;
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Greyling A, Schreuder THA, Landman T, Draijer R, Verheggen RJHM, Hopman MTE, Thijssen DHJ. Elevation in blood flow and shear rate prevents hyperglycemia-induced endothelial dysfunction in healthy subjects and those with type 2 diabetes. J Appl Physiol (1985) 2015; 118:579-85. [PMID: 25593286 DOI: 10.1152/japplphysiol.00936.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hyperglycemia, commonly present after a meal, causes transient impairment in endothelial function. We examined whether increases in blood flow (BF) protect against the hyperglycemia-mediated decrease in endothelial function in healthy subjects and patients with type 2 diabetes mellitus (T2DM). Ten healthy subjects and 10 age- and sex-matched patients with T2DM underwent simultaneous bilateral assessment of brachial artery endothelial function by means of flow-mediated dilation (FMD) using high-resolution echo-Doppler. FMD was examined before and 60, 120, and 150 min after a 75-g oral glucose challenge. We unilaterally manipulated BF by heating one arm between minute 30 and minute 60. Oral glucose administration caused a statistically significant, transient increase in blood glucose in both groups (P < 0.001). Forearm skin temperature, brachial artery BF, and shear rate significantly increased in the heated arm (P < 0.001), and to a greater extent compared with the nonheated arm in both groups (interaction effect P < 0.001). The glucose load caused a transient decrease in FMD% (P < 0.05), whereas heating significantly prevented the decline (interaction effect P < 0.01). Also, when correcting for changes in diameter and shear rate, we found that the hyperglycemia-induced decrease in FMD can be prevented by local heating (P < 0.05). These effects on FMD were observed in both groups. Our data indicate that nonmetabolically driven elevation in BF and shear rate can similarly prevent the hyperglycemia-induced decline in conduit artery endothelial function in healthy volunteers and in patients with type 2 diabetes. Additional research is warranted to confirm that other interventions that increase BF and shear rate equally protect the endothelium when challenged by hyperglycemia.
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Affiliation(s)
- Arno Greyling
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands; Unilever R&D Vlaardingen, The Netherlands; and
| | - Tim H A Schreuder
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Thijs Landman
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Maria T E Hopman
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dick H J Thijssen
- Department of Physiology, Radboud University Medical Center, Nijmegen, The Netherlands; Research Institute for Sports and Exercise Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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Green S, Egaña M, Baldi JC, Lamberts R, Regensteiner JG. Cardiovascular control during exercise in type 2 diabetes mellitus. J Diabetes Res 2015; 2015:654204. [PMID: 25918732 PMCID: PMC4396731 DOI: 10.1155/2015/654204] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/17/2015] [Indexed: 12/31/2022] Open
Abstract
Controlled studies of male and female subjects with type 2 diabetes mellitus (DM) of short duration (~3-5 years) show that DM reduces peak VO2 (L·min(-1) and mL·kg(-1)·min(-1)) by an average of 12-15% and induces a greater slowing of the dynamic response of pulmonary VO2 during submaximal exercise. These effects occur in individuals less than 60 years of age but are reduced or absent in older males and are consistently associated with significant increases in the exercise pressor response despite normal resting blood pressure. This exaggerated pressor response, evidence of exertional hypertension in DM, is manifest during moderate submaximal exercise and coincides with a more constrained vasodilation in contracting muscles. Maximum vasodilation during contractions involving single muscle groups is reduced by DM, and the dynamic response of vasodilation during submaximal contractions is slowed. Such vascular constraint most likely contributes to exertional hypertension, impairs dynamic and peak VO2 responses, and reduces exercise tolerance. There is a need to establish the effect of DM on dynamic aspects of vascular control in skeletal muscle during whole-body exercise and to clarify contributions of altered cardiovascular control and increased arterial stiffness to exertional hypertension.
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Affiliation(s)
- Simon Green
- School of Science and Health, University of Western Sydney, Sydney, NSW 2751, Australia
- Neuroscience Research Australia, Sydney, NSW 2751, Australia
- *Simon Green:
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 1, Ireland
| | - J. Chris Baldi
- Department of Medicine, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Regis Lamberts
- Department of Physiology-HeartOtago, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Judith G. Regensteiner
- Division of General Internal Medicine, Center for Women's Health Research, Department of Medicine, School of Medicine, University of Colorado, Denver, CO 80210, USA
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Madsen SM, Thorup AC, Overgaard K, Bjerre M, Jeppesen PB. Functional and structural vascular adaptations following 8 weeks of low volume high intensity interval training in lower leg of type 2 diabetes patients and individuals at high risk of metabolic syndrome. Arch Physiol Biochem 2015; 121:178-86. [PMID: 26471849 DOI: 10.3109/13813455.2015.1087033] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
UNLABELLED We wished to investigate the effects of 8 weeks of low volume high intensity interval training (HIIT) on endothelial function of popliteal artery and circulating cell adhesion molecules in type 2 diabetes (T2D) patients and matched controls (CON). METHODS Over 8 weeks, non-active T2D patients and CONs cycled three times per week (10 × 60 sec HIIT). Pre- and post-HIIT measurements of endothelial function were conducted by applying flow-mediated dilation (FMD) along with taking venous blood samples. RESULTS Baseline diameter of popliteal artery increased significantly from an average of 5.53 mm to 5.97 mm (∼8%) in the CON-group (p = 0.006) and 5.32 mm to 5.61 mm (∼6%) in the T2D-group (p = 0.009). Peak diameter increased significantly from 5.82 mm to 6.36 mm (∼9%) in the CON-group (p = 0.001) and 5.57 mm to 5.93 mm (∼7%) in the T2D-group (p = 0.004). FMD% increased significantly from 5.12% to 6.58% in the CON-group (p = 0.004) and 4.84% to 5.66% in the T2D-group: (p = 0.045). The shear rate reduced significantly in both groups (CON-group: p = 0.04; T2D-group: p = 0.002). Circulating cell adhesion molecules remained unchanged (p > 0.05). CONCLUSION HIIT induced an improvement of endothelium-dependent FMD and significant outwards artery modelling. No changes in circulating cell adhesion molecules were observed.
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Affiliation(s)
- Søren Møller Madsen
- a Department of Endocrinology and Internal Medicine , Aarhus Sygehus THG, Aarhus University Hospital , Aarhus C , Denmark
| | - Anne Cathrine Thorup
- a Department of Endocrinology and Internal Medicine , Aarhus Sygehus THG, Aarhus University Hospital , Aarhus C , Denmark
| | - Kristian Overgaard
- b Section of Sport Science, Department of Public Health, Aarhus University , Aarhus , Denmark , and
| | - Mette Bjerre
- c The Medical Research Laboratory, Department of Clinical Medicine, Faculty of Health, Aarhus University , Denmark
| | - Per Bendix Jeppesen
- a Department of Endocrinology and Internal Medicine , Aarhus Sygehus THG, Aarhus University Hospital , Aarhus C , Denmark
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Kiely C, O'Connor E, O'Shea D, Green S, Egaña M. Hemodynamic responses during graded and constant-load plantar flexion exercise in middle-aged men and women with type 2 diabetes. J Appl Physiol (1985) 2014; 117:755-64. [DOI: 10.1152/japplphysiol.00555.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We tested the hypotheses that type 2 diabetes (T2D) impairs the 1) leg hemodynamic responses to an incremental intermittent plantar-flexion exercise and 2) dynamic responses of leg vascular conductance (LVC) during low-intensity (30% maximal voluntary contraction, MVC) and high-intensity (70% MVC) constant-load plantar-flexion exercise in the supine posture. Forty-four middle-aged individuals with T2D (14 women), and 35 healthy nondiabetic (ND) individuals (18 women) were tested. Leg blood flow (LBF) was measured between each contraction using venous occlusion plethysmography. During the incremental test peak force (Fpeak) relative to MVC was significantly reduced ( P < 0.05) in men and women with T2D compared with their respective nondiabetic counterparts. Peak LBF and the slope of LBF relative to percentage Fpeak were also reduced ( P < 0.05) in women with T2D compared with healthy women (peak blood flow, 460.6 ± 126.8 vs. 628.3 ± 347.7 ml/min; slope, 3.78 ± 1.74 vs. 5.85 ± 3.14 ml·min−1·%Fpeak−1) and in men with T2D compared with nondiabetic men (peak blood flow, 621.7 ± 241.3 vs. 721.2 ± 359.7 ml/min; slope, 5.75 ± 2.66 vs. 6.33 ± 3.63 ml·min−1·%Fpeak−1). During constant-load contractions at 30% MVC T2D did not affect the dynamic responses of LVC (LBF/MAP). However, at 70% MVC [completed by a subgroup of participants (20 with T2D, 6 women; 13 ND, 6 women)] the time constant of the second growth phase of LVC was longer and the amplitude of the first growth phase was lower ( P < 0.05 for both) in men and women with T2D. The results suggest that the T2D-induced impairments in performance of the leg muscles are related to reductions in blood flow in both men and women.
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Affiliation(s)
- Catherine Kiely
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Eamonn O'Connor
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Donal O'Shea
- Endocrinology, St Columcille's and St Vincent's Hospitals, Dublin, Ireland; and
| | - Simon Green
- School of Science and Health and School of Medicine, University of Western Sydney, Sydney, Australia
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
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