1
|
Al-Horani RA, Alsays KM, Abo Alrob O. Obesity blunts insulin sensitivity improvements and attenuates strength gains following resistance training in nondiabetic men. Eur J Appl Physiol 2024; 124:1425-1437. [PMID: 38100040 DOI: 10.1007/s00421-023-05370-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/10/2023] [Indexed: 04/28/2024]
Abstract
PURPOSE Impaired insulin sensitivity is central in the etiology of type 2 diabetes in people with obesity. The effectiveness of resistance training (RE) alone in improving insulin sensitivity in people with obesity is undetermined. This study aimed to determine the influence of obesity on insulin sensitivity responses to RE. METHODS Nineteen sedentary men were allocated to Lean (BMI 22.7 ± 2.5 kg m-2; n = 10) or Obese group (BMI 33.2 ± 3.2 kg m-2; n = 9). Participants were evaluated before and after a 10-week supervised progressive RE (3 sets of 10 repetition maximum (RM), 3 d/wk) for insulin sensitivity indexes using an oral glucose tolerance test, body composition using anthropometrics, and strength using 1RM. RESULTS Groups were matched at baseline for all variables except for body composition and absolute strength. Body fat was not changed in both groups. Matsuda insulin sensitivity index, hepatic insulin resistance, and insulin area under the curve improved by 64.3 ± 61.9 unit, - 58.2 ± 102.9 unit, 2.3 ± 4.1 unit, and - 721.6 ± 858.2 µU/ml, respectively, only in the Lean group. The increased 1RM% for leg press was greater in the Lean (49.5 ± 18.7%) than in the Obese (31.5 ± 13.9), but not different for bench press (18.0 ± 9.1% vs. 16.4 ± 6.0%, respectively). CONCLUSION Sustained obesity precludes insulin sensitivity improvements and attenuates strength gains in response to progressive RE. Additional strategies such as caloric restriction might be necessary for RE to improve insulin sensitivity, particularly at high levels of obesity.
Collapse
Affiliation(s)
- Ramzi A Al-Horani
- Department of Exercise Science, Yarmouk University, Irbid, 211-63, Jordan.
| | - Khaled M Alsays
- Department of Exercise Science, Yarmouk University, Irbid, 211-63, Jordan
| | - Osama Abo Alrob
- Clinical Pharmacy and Pharmacy Practice Department, Faculty of Pharmacy, Yarmouk University, Irbid, 211-63, Jordan
| |
Collapse
|
2
|
Collins KA, Ross LM, Slentz CA, Huffman KM, Kraus WE. Differential Effects of Amount, Intensity, and Mode of Exercise Training on Insulin Sensitivity and Glucose Homeostasis: A Narrative Review. SPORTS MEDICINE - OPEN 2022; 8:90. [PMID: 35834023 PMCID: PMC9283590 DOI: 10.1186/s40798-022-00480-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 06/18/2022] [Indexed: 11/29/2022]
Abstract
As type 2 diabetes remains a leading cause of morbidity and mortality, identifying the most appropriate preventive treatment early in the development of disease is an important public health matter. In general, lifestyle interventions incorporating exercise and weight loss via caloric restriction improve cardiometabolic risk by impacting several key markers of insulin sensitivity and glucose homeostasis. However, variations in the effects of specific types of exercise interventions on these markers have led to conflicting results surrounding the optimal amount, intensity, and mode of exercise for optimal effects. Moreover, the addition of weight loss via caloric restriction to exercise interventions appears to differentially impact changes in body composition, metabolism, and insulin sensitivity compared to exercise alone. Determining the optimal amount, intensity, and mode of exercise having the most beneficial impact on glycemic status is both: (1) clinically important to provide guidelines for appropriate exercise prescription; and (2) physiologically important to understand the pathways by which exercise—with and without weight loss—impacts glycemic status to enhance precision lifestyle medicine. Thus, the purposes of this narrative review are to: (1) summarize findings from the three Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE) randomized trials regarding the differential effects of exercise amount, intensity, and mode on insulin action and glucose homeostasis markers; and (2) compare the STRRIDE findings to other published dose–response exercise trials in order to piece together the various physiologic pathways by which specific exercise interventions—with or without weight loss—impact glycemic status.
Collapse
|
3
|
Moreno-Cabañas A, Ortega JF, Morales-Palomo F, Ramirez-Jimenez M, Alvarez-Jimenez L, Mora-Rodriguez R. One Bout of Resistance Training Does Not Enhance Metformin Actions in Prediabetic and Diabetic Individuals. Med Sci Sports Exerc 2022; 54:1043-1050. [PMID: 35142713 DOI: 10.1249/mss.0000000000002889] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to determine the separated and combined effects of metformin and resistance exercise on glycemic control, insulin sensitivity, and insulin-like growth factor 1 (IGF-1) in overweight/obese individuals with prediabetes and type 2 diabetes mellitus. METHODS Fourteen adults with a body mass index of 32.1 ± 4.1 kg·m-2, insulin resistance (HOMA-2 1.6 ± 0.6), and poor glycemic control (glycated hemoglobin, 6.9% ± 0.9%; 51.9 ± 10.7 mmol·mol-1) while taking metformin (1561 ± 470 g·d-1) were recruited. Participants underwent four 72-h long experimental trials in a randomized counterbalanced order, either 1) taking metformin (MET), 2) replacing metformin by placebo pills (PLAC), 3) taking placebo and undergoing a resistance training bout (RT + PLAC), and 4) taking metformin and undergoing the same RT bout (RT + MET). Interstitial fluid glucose concentration was frequently sampled to obtain 72-h glucose area under the curve (GAUC) and the percentage hyperglycemic glucose readings (>180 mg·dL-1; GPEAKS). Insulin sensitivity (i.e., HOMA-2) and IGF-1 were also assessed. RESULTS HOMA-2 was not affected by treatments. GAUC and GPEAKS were similarly reduced below PLAC during RT + MET and MET (all P < 0.05). In contrast, RT + PLAC did not affect glucose concentration. Metformin decreased serum IGF-1 concentrations (P = 0.006), and RT did not reverse this reduction. CONCLUSIONS A bout of full-body RT does not interfere or aid on metformin's blood glucose-lowering actions in individuals with prediabetes and type 2 diabetes mellitus.
Collapse
|
4
|
Schwarzer M, Molis A, Schenkl C, Schrepper A, Britton SL, Koch LG, Doenst T. Genetically determined exercise capacity affects systemic glucose response to insulin in rats. Physiol Genomics 2021; 53:395-405. [PMID: 34297615 DOI: 10.1152/physiolgenomics.00014.2021] [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: 11/22/2022] Open
Abstract
INTRODUCTION Aerobic exercise capacity is inversely related to morbidity and mortality as well as to insulin resistance. However, exercising in patients has led to conflicting results, presumably because aerobic exercise capacity consists of intrinsic (genetically determined) and extrinsic (environmentally determined) parts. The contribution of both parts to insulin sensitivity is also not clear. We investigated sedentary and exercised (aerobic interval training) high (HCR) and low capacity runners (LCR) differing in their genetically determined aerobic exercise capacity to determine the contribution of both parts to insulin sensitivity. METHODS AND RESULTS LCR and HCR differed in their untrained exercise capacity and body weight. Sedentary LCR displayed a diabetic phenotype with higher random glucose, lower glucose infusion rate during hyperinsulinemic euglycemic clamping than HCR. Echocardiography showed equal morphological and functional parameters and no change with exercise. Four weeks of exercise caused significant improvements in aerobic exercise capacity, which was more pronounced in LCR. However, with respect to glucose use, exercise affected HCR only. In these animals, exercise increased 2-deoxyglucose uptake in gastrocnemius (+58.5 %, p= 0.1) and in epididymal fat (+106 %; p<0.05). Citrate synthase activity also increased in these tissues (gastrocnemius 69 % epididymal fat 63 %). CONCLUSION In our model of HCR and LCR, genetic predisposition for low exercise capacity is associated with impaired insulin sensitivity and impedes exercise-induced improvements in insulin response. Our results suggest that genetic predisposition for low aerobic exercise capacity impairs insulin response, which may not be overcome by exercise.
Collapse
Affiliation(s)
- Michael Schwarzer
- Department of Cardiothoracic Surgery, Jena University Hospital, Jena, Germany
| | - Annika Molis
- Department of Cardiothoracic Surgery, Jena University Hospital, Jena, Germany
| | - Christina Schenkl
- Department of Cardiothoracic Surgery, Jena University Hospital, Jena, Germany
| | - Andrea Schrepper
- Department of Cardiothoracic Surgery, Jena University Hospital, Jena, Germany
| | - Steven L Britton
- Department of Anesthesiology, Department of Molecular and Integrative Physiology, University of Michigan-Ann Arbor, Ann Arbor, Michigan, United States
| | - Lauren Gerard Koch
- Department of Physiology and Pharmacology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States
| | - Torsten Doenst
- Department of Cardiothoracic Surgery, Jena University Hospital, Jena, Germany
| |
Collapse
|
5
|
Paquin J, Lagacé JC, Brochu M, Dionne IJ. Exercising for Insulin Sensitivity - Is There a Mechanistic Relationship With Quantitative Changes in Skeletal Muscle Mass? Front Physiol 2021; 12:656909. [PMID: 34054574 PMCID: PMC8149906 DOI: 10.3389/fphys.2021.656909] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/14/2021] [Indexed: 12/29/2022] Open
Abstract
Skeletal muscle (SM) tissue has been repetitively shown to play a major role in whole-body glucose homeostasis and overall metabolic health. Hence, SM hypertrophy through resistance training (RT) has been suggested to be favorable to glucose homeostasis in different populations, from young healthy to type 2 diabetic (T2D) individuals. While RT has been shown to contribute to improved metabolic health, including insulin sensitivity surrogates, in multiple studies, a universal understanding of a mechanistic explanation is currently lacking. Furthermore, exercised-improved glucose homeostasis and quantitative changes of SM mass have been hypothesized to be concurrent but not necessarily causally associated. With a straightforward focus on exercise interventions, this narrative review aims to highlight the current level of evidence of the impact of SM hypertrophy on glucose homeostasis, as well various mechanisms that are likely to explain those effects. These mechanistic insights could provide a strengthened rationale for future research assessing alternative RT strategies to the current classical modalities, such as low-load, high repetition RT or high-volume circuit-style RT, in metabolically impaired populations.
Collapse
Affiliation(s)
- Jasmine Paquin
- Research Centre on Aging, Affiliated With CIUSSS de l'Estrie-CHUS, Sherbrooke, QC, Canada.,Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Jean-Christophe Lagacé
- Research Centre on Aging, Affiliated With CIUSSS de l'Estrie-CHUS, Sherbrooke, QC, Canada.,Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Martin Brochu
- Research Centre on Aging, Affiliated With CIUSSS de l'Estrie-CHUS, Sherbrooke, QC, Canada.,Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| | - Isabelle J Dionne
- Research Centre on Aging, Affiliated With CIUSSS de l'Estrie-CHUS, Sherbrooke, QC, Canada.,Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC, Canada
| |
Collapse
|
6
|
Richter-Stretton GL, Fenning AS, Vella RK. Skeletal muscle - A bystander or influencer of metabolic syndrome? Diabetes Metab Syndr 2020; 14:867-875. [PMID: 32562864 DOI: 10.1016/j.dsx.2020.06.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIMS Metabolic syndrome is the concurrent presentation of multiple cardiovascular risk factors, including obesity, insulin resistance, hyperglycemia, dyslipidemia and hypertension. It has been suggested that some of these risk factors can have detrimental effects on the skeletal muscle while others can be a direct result of skeletal muscle abnormalities, showing a two-way directionality in the pathogenesis of the condition. This review aims to explore this bidirectional correlation by discussing the impact of metabolic syndrome on skeletal muscle tissue in general and will also discuss ways in which skeletal muscle alterations may contribute to the pathogenesis of metabolic syndrome. METHODS Literature searches were conducted with key words (e.g. metabolic syndrome, skeletal muscle, hyperglycemia) using PubMed, EBSCOhost, Science Direct and Google Scholar. All article types were included in the search. RESULTS The pathological mechanisms associated with metabolic syndrome, such as hyperglycemia and inflammation, have been associated with changes in skeletal muscle fiber composition, metabolism, insulin sensitivity, mitochondrial function, and strength. Additionally, some skeletal muscle alterations, particularly mitochondrial dysfunction and insulin resistance, are suggested to contribute to the development of metabolic syndrome. For example, the suggested underlying mechanisms of sarcopenia development are also contributors to metabolic syndrome pathogenesis. CONCLUSION Whilst numerous studies have identified a relationship between metabolic syndrome and skeletal muscle abnormalities, further investigation into the underlying mechanisms is needed to elucidate the best prevention and management strategies for these conditions.
Collapse
Affiliation(s)
- Gina L Richter-Stretton
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia, 4702; Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, University of Queensland St Lucia, Brisbane, Queensland, Australia, 4072.
| | - Andrew S Fenning
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia, 4702
| | - Rebecca K Vella
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland, Australia, 4702; School of Medicine, Griffith University, Sunshine Coast, Queensland, Australia, 4572
| |
Collapse
|
7
|
Skeletal Muscle Fiber Adaptations Following Resistance Training Using Repetition Maximums or Relative Intensity. Sports (Basel) 2019; 7:sports7070169. [PMID: 31373325 PMCID: PMC6680702 DOI: 10.3390/sports7070169] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/04/2019] [Accepted: 07/07/2019] [Indexed: 11/16/2022] Open
Abstract
The purpose of the study was to compare the physiological responses of skeletal muscle to a resistance training (RT) program using repetition maximum (RM) or relative intensity (RISR). Fifteen well-trained males underwent RT 3 d·wk−1 for 10 weeks in either an RM group (n = 8) or RISR group (n = 7). The RM group achieved a relative maximum each day, while the RISR group trained based on percentages. The RM group exercised until muscular failure on each exercise, while the RISR group did not reach muscular failure throughout the intervention. Percutaneous needle biopsies of the vastus lateralis were obtained pre-post the training intervention, along with ultrasonography measures. Dependent variables were: Fiber type-specific cross-sectional area (CSA); anatomical CSA (ACSA); muscle thickness (MT); mammalian target of rapamycin (mTOR); adenosine monophosphate protein kinase (AMPK); and myosin heavy chains (MHC) specific for type I (MHC1), type IIA (MHC2A), and type IIX (MHC2X). Mixed-design analysis of variance and effect size using Hedge’s g were used to assess within- and between-group alterations. RISR statistically increased type I CSA (p = 0.018, g = 0.56), type II CSA (p = 0.012, g = 0.81), ACSA (p = 0.002, g = 0.53), and MT (p < 0.001, g = 1.47). RISR also yielded a significant mTOR reduction (p = 0.031, g = −1.40). Conversely, RM statistically increased only MT (p = 0.003, g = 0.80). Between-group effect sizes supported RISR for type I CSA (g = 0.48), type II CSA (g = 0.50), ACSA (g = 1.03), MT (g = 0.72), MHC2X (g = 0.31), MHC2A (g = 0.87), and MHC1 (g = 0.59); with all other effects being of trivial magnitude (g < 0.20). Our results demonstrated greater adaptations in fiber size, whole-muscle size, and several key contractile proteins when using RISR compared to RM loading paradigms.
Collapse
|
8
|
Newman AA, Grimm NC, Wilburn JR, Schoenberg HM, Trikha SRJ, Luckasen GJ, Biela LM, Melby CL, Bell C. Influence of Sodium Glucose Cotransporter 2 Inhibition on Physiological Adaptation to Endurance Exercise Training. J Clin Endocrinol Metab 2019; 104:1953-1966. [PMID: 30597042 DOI: 10.1210/jc.2018-01741] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 12/21/2018] [Indexed: 12/11/2022]
Abstract
CONTEXT The combination of two beneficial antidiabetes interventions, regular exercise and pharmaceuticals, is intuitively appealing. However, metformin, the most commonly prescribed diabetes medication, attenuates the favorable physiological adaptations to exercise; in turn, exercise may impede the action of metformin. OBJECTIVE We sought to determine the influence of an alternative diabetes treatment, sodium glucose cotransporter 2 (SGLT2) inhibition, on the response to endurance exercise training. DESIGN, PARTICIPANTS, AND INTERVENTION In a randomized, double-blind, repeated measures parallel design, 30 sedentary overweight and obese men and women were assigned to 12 weeks of supervised endurance exercise training, with daily ingestion of either a placebo or SGLT2 inhibitor (dapagliflozin: ≤10 mg/day). OUTCOME MEASUREMENTS AND RESULTS Endurance exercise training favorably modified body mass, body composition (dual-energy x-ray absorptiometry), peak oxygen uptake (graded exercise with indirect calorimetry), responses to standardized submaximal exercise (indirect calorimetry, heart rate, and blood lactate), and skeletal muscle (vastus lateralis) citrate synthase activity (main effects of exercise training, all P < 0.05); SGLT2 inhibition did not influence any of these physiological adaptations (exercise training × treatment interaction, all P > 0.05). However, after endurance exercise training, fasting blood glucose was greater with SGLT2 inhibition, and increased insulin sensitivity (oral glucose tolerance test/Matsuda index) was abrogated with SGLT2 inhibition (exercise training × treatment interaction, P < 0.01). CONCLUSION The efficacy of combining two beneficial antidiabetes interventions, regular endurance exercise and SGLT2 inhibition, was not supported. SGLT2 inhibition blunted endurance exercise training-induced improvements in insulin sensitivity, independent of effects on aerobic fitness or body composition.
Collapse
Affiliation(s)
- Alissa A Newman
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Nathan C Grimm
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Jessie R Wilburn
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Hayden M Schoenberg
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - S Raj J Trikha
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Gary J Luckasen
- Medical Center of the Rockies Foundation, University of Colorado Health, Loveland, Colorado
| | - Laurie M Biela
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| | - Christopher L Melby
- Department of Food Science and Human Nutrition, Colorado State University, Fort Collins, Colorado
| | - Christopher Bell
- Department of Health and Exercise Science, Colorado State University, Fort Collins, Colorado
| |
Collapse
|
9
|
The Role of AMPK in the Regulation of Skeletal Muscle Size, Hypertrophy, and Regeneration. Int J Mol Sci 2018; 19:ijms19103125. [PMID: 30314396 PMCID: PMC6212977 DOI: 10.3390/ijms19103125] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/08/2018] [Accepted: 10/09/2018] [Indexed: 12/22/2022] Open
Abstract
AMPK (5’-adenosine monophosphate-activated protein kinase) is heavily involved in skeletal muscle metabolic control through its regulation of many downstream targets. Because of their effects on anabolic and catabolic cellular processes, AMPK plays an important role in the control of skeletal muscle development and growth. In this review, the effects of AMPK signaling, and those of its upstream activator, liver kinase B1 (LKB1), on skeletal muscle growth and atrophy are reviewed. The effect of AMPK activity on satellite cell-mediated muscle growth and regeneration after injury is also reviewed. Together, the current data indicate that AMPK does play an important role in regulating muscle mass and regeneration, with AMPKα1 playing a prominent role in stimulating anabolism and in regulating satellite cell dynamics during regeneration, and AMPKα2 playing a potentially more important role in regulating muscle degradation during atrophy.
Collapse
|
10
|
MacLean C, Dillon J, Babraj JA, Vollaard NB. The effect of low volume sprint interval training in patients with non-alcoholic fatty liver disease. PHYSICIAN SPORTSMED 2018; 46:87-92. [PMID: 29183220 DOI: 10.1080/00913847.2018.1411171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES Exercise is an important part of disease management in patients with non-alcoholic fatty liver disease (NAFLD), but adherence to current exercise recommendations is poor. Novel low-volume sprint interval training (SIT) protocols with total training time commitments of ≤30 min per week have been shown to improve cardiometabolic risk and functional capacity in healthy sedentary participants, but the efficacy of such protocols in the management of NAFLD remains unknown. The aim of the present study was to examine whether a low-volume SIT protocol can be used to improve liver function, insulin resistance, body composition, physical fitness, cognitive function and general well-being in patients with NAFLD. METHODS In the present study, 7 men and 2 women with NAFLD (age: 45 ± 8 y, BMI: 28.7 ± 4.1 kg·m-2) completed a 6-week control period followed by 6 weeks of twice-weekly SIT sessions (5-10 × 6-s 'all-out' cycle sprints). Body composition, blood pressure, liver function, metabolic function, functional capacity, cognitive function and quality of life were assessed at baseline, following the control period, and following the SIT intervention. RESULTS Walking speed during the walk test (+12%), estimated V̇O2max (+8%), verbal fluency (+44%), and blood platelet count (+12%; all p < 0.05) significantly increased during the control period. These measures remained significantly raised compared to baseline following the SIT intervention, but did not significantly change any further compared to the post-control time-point. Diastolic blood pressure decreased from 87 ± 10 to 77 ± 8 mm Hg from the end of the control period to the end of the SIT intervention (p < 0.05). CONCLUSION This study does not support the use of 6 weeks of a low volume SIT protocol involving twice-weekly sessions with 5-10 × 6-s 'all-out' cycle sprints as an intervention for NAFLD disease management.
Collapse
Affiliation(s)
| | - John Dillon
- b School of Medicine , University of Dundee, Ninewells Hospital & Medical School , Dundee , UK
| | - John A Babraj
- c School of Social & Health Sciences , Abertay University , Dundee , UK
| | - Niels Bj Vollaard
- d Faculty of Health Sciences and Sport , University of Stirling , Stirling , UK
| |
Collapse
|
11
|
Albarello R, Boufleur Farinha J, Reckelberg Azambuja C, Lopes dos Santos D. Efeitos do treinamento resistido sobre o perfil lipídico de indivíduos com síndrome metabólica. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.ramd.2014.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
12
|
Stuart CA, Lee ML, South MA, Howell MEA, Stone MH. Muscle hypertrophy in prediabetic men after 16 wk of resistance training. J Appl Physiol (1985) 2017; 123:894-901. [PMID: 28663372 DOI: 10.1152/japplphysiol.00023.2017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 06/11/2017] [Accepted: 06/22/2017] [Indexed: 12/25/2022] Open
Abstract
Resistance training of healthy young men typically results in muscle hypertrophy and a shift in vastus lateralis composition away from type IIx fibers to an increase in IIa fiber content. Our previous studies of 8 wk of resistance training found that many metabolic syndrome men and women paradoxically increased IIx fibers with a decrease in IIa fibers. To confirm the hypothesis that obese subjects might have muscle remodeling after resistance training very different from healthy lean subjects, we subjected a group of nine obese male volunteers to progressive resistance training for a total of 16 wk. In these studies, weight loss was discouraged so that muscle changes would be attributed to the training alone. Detailed assessments included comparisons of histological examinations of needle biopsies of vastus lateralis muscle pretraining and at 8 and 16 wk. Prolonging the training from 8 to 16 wk resulted in increased strength, improved body composition, and more muscle fiber hypertrophy, but euglycemic clamp-quantified insulin responsiveness did not improve. Similar to prior studies, muscle fiber composition shifted toward more fast-twitch type IIx fibers (23 to 42%). Eight weeks of resistance training increased the muscle expression of phosphorylated Akt2 and mTOR. Muscle GLUT4 expression increased, although insulin receptor and IRS-1 expression did not change. We conclude that resistance training of prediabetic obese subjects is effective at changing muscle, resulting in fiber hypertrophy and increased type IIx fiber content, and these changes continue up to 16 wk of training.NEW & NOTEWORTHY Obese, insulin-resistant men responded to 16 wk of progressive resistance training with muscle hypertrophy and increased strength and a shift in muscle fiber composition toward fast-twitch, type IIx fibers. Activation of muscle mTOR was increased by 8 wk but did not increase further at 16 wk despite continued augmentation of peak power and rate of force generation.
Collapse
Affiliation(s)
- Charles A Stuart
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee;
| | - Michelle L Lee
- Department of Allied Health, College of Clinical and Rehabilitative Health, East Tennessee State University, Johnson City, Tennessee and
| | - Mark A South
- Department of Exercise and Sports Science, Clemmer College of Education, East Tennessee State University, Johnson City, Tennessee
| | - Mary E A Howell
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Michael H Stone
- Department of Exercise and Sports Science, Clemmer College of Education, East Tennessee State University, Johnson City, Tennessee
| |
Collapse
|
13
|
Stuart CA, Lee ML, South MA, Howell MEA, Cartwright BM, Ramsey MW, Stone MH. Pre-Training Muscle Characteristics of Subjects Who Are Obese Determine How Well Exercise Training Will Improve Their Insulin Responsiveness. J Strength Cond Res 2017; 31:798-808. [PMID: 27379957 DOI: 10.1519/jsc.0000000000001530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Stuart, CA, Lee, ML, South, MA, Howell, MEA, Cartwright, BM, Ramsey, MW, and Stone, MH. Pre-training muscle characteristics of subjects who are obese determine how well exercise training will improve their insulin responsiveness. J Strength Cond Res 31(3): 798-808, 2017-Only half of prediabetic subjects who are obese who underwent exercise training without weight loss increased their insulin responsiveness. We hypothesized that those who improved their insulin responsiveness might have pretraining characteristics favoring a positive response to exercise training. Thirty nondiabetic subjects who were obese volunteered for 8 weeks of either strength training or endurance training. During training, subjects increased their caloric intake to prevent weight loss. Insulin responsiveness by euglycemic clamps and muscle fiber composition, and expression of muscle key biochemical pathways were quantified. Positive responders initially had 52% higher intermediate muscle fibers (fiber type IIa) with 27% lower slow-twitch fibers (type I) and 23% lower expression of muscle insulin receptors. Whether after weight training or stationary bike training, positive responders' fiber type shifted away from type I and type IIa fibers to an increased proportion of type IIx fibers (fast twitch). Muscle insulin receptor expression and glucose transporter type 4 (GLUT4) expression increased in all trained subjects, but these moderate changes did not consistently translate to improvement in whole-body insulin responsiveness. Exercise training of previously sedentary subjects who are obese can result in muscle remodeling and increased expression of key elements of the insulin pathway, but in the absence of weight loss, insulin sensitivity improvement was modest and limited to about half of the participants. Our data suggest rather than responders being more fit, they may have been less fit, only catching up to the other half of subjects who are obese whose insulin responsiveness did not increase beyond their pretraining baseline.
Collapse
Affiliation(s)
- Charles A Stuart
- 1Department of Internal Medicine, Quillen College of Medicine; 2Department of Allied Health, College of Clinical and Rehabilitative Health; and 3Department of Exercise and Sports Science, Clemmer College of Education, East Tennessee State University, Johnson City, Tennessee
| | | | | | | | | | | | | |
Collapse
|
14
|
Guadalupe-Grau A, Fernández-Elías VE, Ortega JF, Dela F, Helge JW, Mora-Rodriguez R. Effects of 6-month aerobic interval training on skeletal muscle metabolism in middle-aged metabolic syndrome patients. Scand J Med Sci Sports 2017; 28:585-595. [DOI: 10.1111/sms.12881] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2017] [Indexed: 12/20/2022]
Affiliation(s)
- A. Guadalupe-Grau
- Xlab; Department of Biomedical Sciences; Faculty of Health Sciences; Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
- ImFINE Research Group; Department of Health and Human Performance; Technical University of Madrid; Madrid Spain
| | - V. E. Fernández-Elías
- Exercise Physiology Laboratory at Toledo; University of Castilla-La Mancha; Toledo Spain
- Department of Sport Science; European University of Madrid; Madrid Spain
| | - J. F. Ortega
- Exercise Physiology Laboratory at Toledo; University of Castilla-La Mancha; Toledo Spain
| | - F. Dela
- Xlab; Department of Biomedical Sciences; Faculty of Health Sciences; Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
| | - J. W. Helge
- Xlab; Department of Biomedical Sciences; Faculty of Health Sciences; Center for Healthy Aging; University of Copenhagen; Copenhagen Denmark
| | - R. Mora-Rodriguez
- Exercise Physiology Laboratory at Toledo; University of Castilla-La Mancha; Toledo Spain
| |
Collapse
|
15
|
South MA, Layne AS, Stuart CA, Triplett NT, Ramsey M, Howell ME, Sands WA, Mizuguchi S, Hornsby WG, Kavanaugh AA, Stone MH. Effects of Short-Term Free-Weight and Semiblock Periodization Resistance Training on Metabolic Syndrome. J Strength Cond Res 2016; 30:2682-96. [PMID: 27465635 DOI: 10.1519/jsc.0000000000001570] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
South, MA, Layne, AS, Stuart, CA, Triplett, NT, Ramsey, MW, Howell, ME, Sands, WA, Mizuguchi, S, Hornsby, WG, Kavanaugh, AA, and Stone, MH. Effects of short-term free-weight and semiblock periodization resistance training on metabolic syndrome. J Strength Cond Res 30(10): 2682-2696, 2016-The effects of short-term resistance training on performance and health variables associated with prolonged sedentary lifestyle and metabolic syndrome (MS) were investigated. Resistance training may alter a number of health-related, physiological, and performance variables. As a result, resistance training can be used as a valuable tool in ameliorating the effects of a sedentary lifestyle including those associated with MS. Nineteen previously sedentary subjects (10 with MS and 9 with nonmetabolic syndrome [NMS]) underwent 8 weeks of supervised resistance training. Maximum strength was measured using an isometric midthigh pull and resulting force-time curve. Vertical jump height (JH) and power were measured using a force plate. The muscle cross-sectional area (CSA) and type were examined using muscle biopsy and standard analysis techniques. Aerobic power was measured on a cycle ergometer using a ParvoMedics 2400 Metabolic system. Endurance was measured as time to exhaustion on a cycle ergometer. After training, maximum isometric strength, JH, jump power, and V[Combining Dot Above]O2peak increased by approximately 10% (or more) in both the metabolic and NMS groups (both male and female subjects). Over 8 weeks of training, body mass did not change statistically, but percent body fat decreased in subjects with the MS and in women, and lean body mass increased in all groups (p ≤ 0.05). Few alterations were noted in the fiber type. Men had larger CSAs compared those of with women, and there was a fiber-specific trend toward hypertrophy over time. In summary, 8 weeks of semiblock free-weight resistance training improved several performance variables and some cardiovascular factors associated with MS.
Collapse
Affiliation(s)
- Mark A South
- 1Department of Exercise and Sport Science, Center of Excellence for Sport Science and Coach Education, East Tennessee State University, Johnson City, Tennessee; Departments of 2Applied Physiology and Kinesiology; 3Aging and Geriatric Research, University of Florida, Gainesville, Florida; 4Department of Internal Medicine, Quillen School of Medicine, East Tennessee State University, Johnson City, Tennessee; 5Department of Health and Exercise Science, Appalachian State University, Boone, North Carolina; and 6Department of Coaching and Teaching Studies, College of Physical Activity and Sport Sciences, West Virginia University, Morgantown, West Virginia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Pierard M, Conotte S, Tassin A, Boutry S, Uzureau P, Boudjeltia KZ, Legrand A. Interactions of exercise training and high-fat diet on adiponectin forms and muscle receptors in mice. Nutr Metab (Lond) 2016; 13:75. [PMID: 27822289 PMCID: PMC5094086 DOI: 10.1186/s12986-016-0138-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/21/2016] [Indexed: 01/08/2023] Open
Abstract
Background Metabolic syndrome (MetS) is characterized by systemic disturbances that increase cardiovascular risk. Adiponectin (Ad) exhibits a cardioprotective function because of its anti-inflammatory and anti-atherosclerotic properties. In the bloodstream, this adipocytokine circulates on multimers (Admer), among which high molecular weight (HMW) are the most active forms. Because alterations of Ad plasmatic levels, Admer distribution and receptor (AdipoR) expression have been described in murine models and obese patients, strategies that aim to enhance Ad production or its effect on target tissues are the subject of intense investigations. While exercise training is well known to be beneficial for reducing cardiovascular risk, the contribution of Ad is still controversial. Our aim was to evaluate the effect of exercise training on Ad production, Admer distribution and AdipoR muscle expression in a murine model of MetS. Methods At 6 weeks of age, mice were submitted to a standard (SF) or high-fat high-sugar (HF) diet for 10 weeks. After 2 weeks, the SF- and HF-fed animals were randomly assigned to a training program (SFT, HFT) or not (SFC, HFC). The trained groups were submitted to sessions of running on a treadmill 5 days a week. Results and conclusions The HF mice presented the key problems associated with MetS (increased caloric intake, body weight, glycemia and fat mass), a change in Admer distribution in favor of the less-active forms and increased AdipoR2 expression in muscle. In contrast, exercise training reversed some of the adverse effects of a HF diet (increased glucose tolerance, better caloric intake control) without any modifications in Ad production and Admer distribution. However, increased AdipoR1 muscle expression was observed in trained mice, but this effect was hampered by HF diet. These data corroborate a recent hypothesis suggesting a functional divergence between AdipoR1 and AdipoR2, with AdipoR1 having the predominant protective action on metabolic function. Electronic supplementary material The online version of this article (doi:10.1186/s12986-016-0138-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Mélany Pierard
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Stéphanie Conotte
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Alexandra Tassin
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| | - Sébastien Boutry
- Department of General, Organic and Biomedical Chemistry, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium.,Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Pierrick Uzureau
- Experimental Medicine Laboratory, Free University of Brussels, CHU de Charleroi, Belgium
| | | | - Alexandre Legrand
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, Mons, Belgium
| |
Collapse
|
17
|
Ruffino JS, Songsorn P, Haggett M, Edmonds D, Robinson AM, Thompson D, Vollaard NBJ. A comparison of the health benefits of reduced-exertion high-intensity interval training (REHIT) and moderate-intensity walking in type 2 diabetes patients. Appl Physiol Nutr Metab 2016; 42:202-208. [PMID: 28121184 DOI: 10.1139/apnm-2016-0497] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Reduced-exertion high-intensity interval training (REHIT) is a genuinely time-efficient intervention that can improve aerobic capacity and insulin sensitivity in sedentary individuals. The present study compared the effects of REHIT and moderate-intensity walking on health markers in patients with type 2 diabetes (T2D) in a counter-balanced crossover study. Sixteen men with T2D (mean ± SD age: 55 ± 5 years, body mass index: 30.6 ± 2.8 kg·m-2, maximal aerobic capacity: 27 ± 4 mL·kg-1·min-1) completed 8 weeks of REHIT (three 10-min low-intensity cycling sessions/week with two "all-out" 10-20-s sprints) and 8 weeks of moderate-intensity walking (five 30-min sessions/week at an intensity corresponding to 40%-55% of heart-rate reserve), with a 2-month wash-out period between interventions. Before and after each intervention, participants underwent an incremental fitness test, an oral glucose tolerance test (OGTT), a whole-body dual-energy X-ray absorptiometry scan, and continuous glucose monitoring. REHIT was associated with a significantly larger increase in maximal aerobic capacity compared with walking (7% vs. 1%; time × intervention interaction effect: p < 0.05). Both REHIT and walking decreased resting mean arterial pressure (-4%; main effect of time: p < 0.05) and plasma fructosamine (-5%; main effect of time: p < 0.05). Neither intervention significantly improved OGTT-derived measures of insulin sensitivity, glycaemic control measured using continuous glucose monitors, blood lipid profile, or body composition. We conclude that REHIT is superior to a 5-fold larger volume of moderate-intensity walking in improving aerobic fitness, but similar to walking REHIT is not an effective intervention for improving insulin sensitivity or glycaemic control in T2D patients in the short term.
Collapse
Affiliation(s)
- José S Ruffino
- a Department for Health, University of Bath, Bath, BA2 7AY, UK
| | | | - Malindi Haggett
- a Department for Health, University of Bath, Bath, BA2 7AY, UK
| | - Daniel Edmonds
- a Department for Health, University of Bath, Bath, BA2 7AY, UK
| | | | - Dylan Thompson
- a Department for Health, University of Bath, Bath, BA2 7AY, UK
| | | |
Collapse
|
18
|
Miles MP, Horrigan LC, Jay SE, Brown KM, Porter JW, Steward AN. Concentric and eccentric exercise, glycemic responses to a postexercise meal, and inflammation in women with high versus low waist circumference. Appl Physiol Nutr Metab 2016; 41:1262-1270. [PMID: 27841026 DOI: 10.1139/apnm-2016-0281] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Carbohydrate ingestion and level of concentric versus eccentric muscle activity may alter exercise-induced health benefits for individuals who have high waist circumference as a metabolic risk factor. The purpose of this study was to determine whether metabolic and inflammation responses to an exercise recovery meal differ between women with lower (Lo-WC, <80 cm) compared with higher (Hi-WC) waist circumference when the exercise is primarily concentric (uphill walking; UPHILL) versus primarily eccentric (downhill walking; DOWNHILL). Recreationally active women (age, 18-39 years; body mass index, 19-35.4 m·kg-2; Lo-WC, n = 13; Hi-WC, n = 10) completed UPHILL, DOWNHILL, and resting (CONTROL) conditions followed 30 min later by a mixed meal tolerance test (MMTT) with carbohydrates to protein ratio of 4:1, and blood glucose, insulin, and inflammation markers were compared across conditions. Compared with Lo-WC, the Hi-WC group had higher (p < 0.05) (i) insulin during the MMTT in CONTROL (mean ± SE; 48.5 ± 8.2 vs 22.9 ± 2.8 pmol·L-1), (ii) baseline (0.7 ± 0.4 vs 2.0 ± 1.7 pg·mL-1) interleukin-6 (IL-6), and (iii) IL-6 responses 8 h after UPHILL and CONTROL. Both groups had (i) increases in IL-6 at 0 h after UPHILL and at 8 h after DOWNHILL, and (ii) lower glycemic responses in UPHILL. Women with Hi-WC had higher IL-6 at rest and delayed increases in IL-6 after a high-carbohydrate meal in all conditions. This is consistent with an inflammation response to the meal and or uphill walking exercise. However, both concentrically and eccentrically biased exercises offered benefits to insulin responses to a high carbohydrate meal for Hi-WC.
Collapse
Affiliation(s)
- Mary P Miles
- Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA.,Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA
| | - Laura C Horrigan
- Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA.,Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA
| | - Sara E Jay
- Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA.,Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA
| | - Karen M Brown
- Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA.,Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA
| | - Jay W Porter
- Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA.,Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA
| | - Andrea N Steward
- Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA.,Montana State University, Dept. of Health and Human Development, Bozeman, MT 59171, USA
| |
Collapse
|
19
|
AbouAssi H, Slentz CA, Mikus CR, Tanner CJ, Bateman LA, Willis LH, Shields AT, Piner LW, Penry LE, Kraus EA, Huffman KM, Bales CW, Houmard JA, Kraus WE. The effects of aerobic, resistance, and combination training on insulin sensitivity and secretion in overweight adults from STRRIDE AT/RT: a randomized trial. J Appl Physiol (1985) 2016; 118:1474-82. [PMID: 25882384 DOI: 10.1152/japplphysiol.00509.2014] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Most health organizations recommend a combination of aerobic training (AT) and resistance training (RT), yet few studies have compared their acute (within 24 h of the last exercise bout) and sustained (after 14 days of no exercise training) effects alone and in combination on glucose metabolism. The present study (Studies Targeting Risk Reduction Interventions through Defined Exercise-Aerobic Training and/or Resistance Training) compared the effects of AT, RT, and the combination (AT/RT) on insulin action at both acute and sustained phases. Subjects (N = 196) were 18-70 yr old (mean age = 50 yr), overweight (mean body mass index = 30 kg/m2), sedentary with moderate dyslipidemia, and were randomized into one of three 8-mo exercise groups: 1) RT: 3 days/wk, 8 exercises, 3 sets/exercise, 8-12 repetitions/set; 2) AT: equivalent to ∼19.2 km/wk (12 miles/wk) at 75% peak O2 consumption; 3) AT/RT: the combination of AT and RT. One hundred forty-four subjects completed the intervention. Eighty-eight subjects completed all pre- and postintervention testing visits. Insulin sensitivity, glucose effectiveness, and disposition index were measured via a frequently sampled intravenous glucose tolerance test with subsequent minimal model analyses. AT/RT resulted in greater improvements in insulin sensitivity, β-cell function (disposition index), and glucose effectiveness than either AT or RT alone (all P < 0.05). Approximately 52% of the improvement in insulin sensitivity by AT/RT was retained 14 days after the last exercise training bout. Neither AT or RT led to acute or chronic improvement in sensitivity index. In summary, only AT/RT (which required twice as much time as either alone) led to significant acute and sustained benefits in insulin sensitivity
Collapse
|
20
|
Malin SK, Liu Z, Barrett EJ, Weltman A. Exercise resistance across the prediabetes phenotypes: Impact on insulin sensitivity and substrate metabolism. Rev Endocr Metab Disord 2016; 17:81-90. [PMID: 27106830 DOI: 10.1007/s11154-016-9352-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Prediabetes is a heterogeneous term that encompasses different origins of insulin resistance and insulin secretion that contribute to distinct patterns of hyperglycemia. In fact, prediabetes is an umbrella term that characterizes individuals at high risk for developing type 2 diabetes (T2D) and/or cardiovascular disease (CVD). Based on current definitions there are at least 3 distinct phenotypes of prediabetes: impaired fasting glucose (IFG), impaired glucose tolerant (IGT), or the combination of both (IFG + IGT). Each phenotype is clinically relevant as they are uniquely recognized as having different levels of risk for progressing to T2D and CVD. Herein, we discuss the underlying pathophysiology that characterizes IFG, IGT and the combination, as well as examine how some of these phenotypes appear resistant to traditional exercise interventions. We propose that substrate metabolism differences between the prediabetes phenotypes may be a unifying mechanism that explains the inter-subject variation in response to exercise seen across obese, metabolic syndrome, pre-diabetic and T2D patients in the current literature. Ultimately, a better understanding of the pathophysiologic mechanisms that govern disturbances responsible for fasting vs. postprandial hyperglycemia and the combination of both is important for designing optimal and personalized exercise treatment strategies that treat and prevent hyperglycemia and CVD risk.
Collapse
Affiliation(s)
- Steven K Malin
- Applied Metabolism & Physiology Laboratory, Department of Kinesiology, University of Virginia, 210 Emmet St., 225A Memorial Gymnasium, Charlottesville, VA, USA.
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA.
| | - Zhenqi Liu
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| | - Eugene J Barrett
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| | - Arthur Weltman
- Applied Metabolism & Physiology Laboratory, Department of Kinesiology, University of Virginia, 210 Emmet St., 225A Memorial Gymnasium, Charlottesville, VA, USA
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville, VA, USA
| |
Collapse
|
21
|
Stuart CA, Stone WL, Howell MEA, Brannon MF, Hall HK, Gibson AL, Stone MH. Myosin content of individual human muscle fibers isolated by laser capture microdissection. Am J Physiol Cell Physiol 2015; 310:C381-9. [PMID: 26676053 DOI: 10.1152/ajpcell.00317.2015] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 12/10/2015] [Indexed: 12/12/2022]
Abstract
Muscle fiber composition correlates with insulin resistance, and exercise training can increase slow-twitch (type I) fibers and, thereby, mitigate diabetes risk. Human skeletal muscle is made up of three distinct fiber types, but muscle contains many more isoforms of myosin heavy and light chains, which are coded by 15 and 11 different genes, respectively. Laser capture microdissection techniques allow assessment of mRNA and protein content in individual fibers. We found that specific human fiber types contain different mixtures of myosin heavy and light chains. Fast-twitch (type IIx) fibers consistently contained myosin heavy chains 1, 2, and 4 and myosin light chain 1. Type I fibers always contained myosin heavy chains 6 and 7 (MYH6 and MYH7) and myosin light chain 3 (MYL3), whereas MYH6, MYH7, and MYL3 were nearly absent from type IIx fibers. In contrast to cardiomyocytes, where MYH6 (also known as α-myosin heavy chain) is seen solely in fast-twitch cells, only slow-twitch fibers of skeletal muscle contained MYH6. Classical fast myosin heavy chains (MHC1, MHC2, and MHC4) were present in variable proportions in all fiber types, but significant MYH6 and MYH7 expression indicated slow-twitch phenotype, and the absence of these two isoforms determined a fast-twitch phenotype. The mixed myosin heavy and light chain content of type IIa fibers was consistent with its role as a transition between fast and slow phenotypes. These new observations suggest that the presence or absence of MYH6 and MYH7 proteins dictates the slow- or fast-twitch phenotype in skeletal muscle.
Collapse
Affiliation(s)
- Charles A Stuart
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee;
| | - William L Stone
- Department of Pediatrics, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee; and
| | - Mary E A Howell
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Marianne F Brannon
- Department of Pediatrics, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee; and
| | - H Kenton Hall
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Andrew L Gibson
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Michael H Stone
- Department of Exercise and Sport Science, Clemmer College of Education, East Tennessee State University, Johnson City, Tennessee
| |
Collapse
|
22
|
Stuart CA, Howell MEA, Cartwright BM, McCurry MP, Lee ML, Ramsey MW, Stone MH. Insulin resistance and muscle insulin receptor substrate-1 serine hyperphosphorylation. Physiol Rep 2014; 2:2/12/e12236. [PMID: 25472611 PMCID: PMC4332214 DOI: 10.14814/phy2.12236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Insulin resistance in metabolic syndrome subjects is profound in spite of muscle insulin receptor and insulin-responsive glucose transporter (GLUT4) expression being nearly normal. Insulin receptor tyrosine kinase phosphorylation of insulin receptor substrate-1 (IRS-1) at Tyr896 is a necessary step in insulin stimulation of translocation of GLUT4 to the cell surface. Serine phosphorylation of IRS-1 by some kinases diminishes insulin action in mice. We evaluated the phosphorylation status of muscle IRS-1 in 33 subjects with the metabolic syndrome and seventeen lean controls. Each underwent euglycemic insulin clamps and a thigh muscle biopsy before and after 8 weeks of either strength or endurance training. Muscle IRS-1 phosphorylation at six sites was quantified by immunoblots. Metabolic syndrome muscle IRS-1 had excess phosphorylation at Ser337 and Ser636 but not at Ser307, Ser789, or Ser1101. Ser337 is a target for phosphorylation by glycogen synthase kinase 3 (GSK3) and Ser636 is phosphorylated by c-Jun N-terminal kinase 1 (JNK1). Exercise training without weight loss did not change the IRS-1 serine phosphorylation. These data suggest that baseline hyperphosphorylation of at least two key serines within muscle IRS-1 diminishes the transmission of the insulin signal and thereby decreases the insulin-stimulated translocation of GLUT4. Excess fasting phosphorylation of muscle IRS-1 at Ser636 may be a major cause of the insulin resistance seen in obesity and might prevent improvement in insulin responsiveness when exercise training is not accompanied by weight loss.
Collapse
Affiliation(s)
- Charles A Stuart
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Mary E A Howell
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Brian M Cartwright
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Melanie P McCurry
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee
| | - Michelle L Lee
- Department of Allied Health, College of Clinical and Rehabilitative Health, East Tennessee State University, Johnson City, Tennessee
| | - Michael W Ramsey
- Department of Exercise and Sports Science, Clemmer College of Education, East Tennessee State University, Johnson City, Tennessee
| | - Michael H Stone
- Department of Exercise and Sports Science, Clemmer College of Education, East Tennessee State University, Johnson City, Tennessee
| |
Collapse
|
23
|
Mora-Rodriguez R, Ortega JF, Hamouti N, Fernandez-Elias VE, Cañete Garcia-Prieto J, Guadalupe-Grau A, Saborido A, Martin-Garcia M, Guio de Prada V, Ara I, Martinez-Vizcaino V. Time-course effects of aerobic interval training and detraining in patients with metabolic syndrome. Nutr Metab Cardiovasc Dis 2014; 24:792-798. [PMID: 24656853 DOI: 10.1016/j.numecd.2014.01.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Revised: 12/20/2013] [Accepted: 01/07/2014] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND AIMS Exercise training can improve health of patients with metabolic syndrome (MetS). However, which MetS factors are most responsive to exercise training remains unclear. We studied the time-course of changes in MetS factors in response to training and detraining. METHODS AND RESULTS Forty eight MetS patients (52 ± 8.8 yrs old; 33 ± 4 BMI) underwent 4 months (3 days/week) of supervised aerobic interval training (AIT) program. After 1 month of training, there were progressive increases in high density lipoprotein cholesterol (HDL-c) and reductions in waist circumference and blood pressure (12 ± 3, -3.9 ± 0.4, and -12 ± 1%, respectively after 4 months; all P < 0.05). However, fasting plasma concentration of triglycerides and glucose were not reduced by training. Insulin sensitivity (HOMA), cardiorespiratory fitness (VO2peak) and exercise maximal fat oxidation (FOMAx) also progressively improved with training (-17 ± 5; 21 ± 2 and 31 ± 8%, respectively, after 4 months; all P < 0.05). Vastus lateralis samples from seven subjects revealed that mitochondrial O2 flux was markedly increased with training (71 ± 11%) due to increased mitochondrial content. After 1 month of detraining, the training-induced improvements in waist circumference and blood pressure were maintained. HDL-c and VO2peak returned to the values found after 1-2 months of training while HOMA and FOMAx returned to pre-training values. CONCLUSIONS The health related variables most responsive to aerobic interval training in MetS patients are waist circumference, blood pressure and the muscle and systemic adaptations to consume oxygen and fat. However, the latter reverse with detraining while blood pressure and waist circumference are persistent to one month of detraining.
Collapse
Affiliation(s)
- R Mora-Rodriguez
- Exercise Physiology Laboratory and GENUD Group University of Castilla-La Mancha, Toledo, Spain.
| | - J F Ortega
- Exercise Physiology Laboratory and GENUD Group University of Castilla-La Mancha, Toledo, Spain
| | - N Hamouti
- Exercise Physiology Laboratory and GENUD Group University of Castilla-La Mancha, Toledo, Spain
| | - V E Fernandez-Elias
- Exercise Physiology Laboratory and GENUD Group University of Castilla-La Mancha, Toledo, Spain
| | | | - A Guadalupe-Grau
- Xlab, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - A Saborido
- Departamento de Bioquímica y Biología Molecular I, University Complutense, Madrid, Spain
| | - M Martin-Garcia
- Exercise Physiology Laboratory and GENUD Group University of Castilla-La Mancha, Toledo, Spain
| | | | - I Ara
- Exercise Physiology Laboratory and GENUD Group University of Castilla-La Mancha, Toledo, Spain
| | - V Martinez-Vizcaino
- Social and Health Care Research Center, University of Castilla-La-Mancha, Cuenca, Spain
| |
Collapse
|
24
|
Stuart CA, South MA, Lee ML, McCurry MP, Howell MEA, Ramsey MW, Stone MH. Insulin responsiveness in metabolic syndrome after eight weeks of cycle training. Med Sci Sports Exerc 2014; 45:2021-9. [PMID: 23669880 DOI: 10.1249/mss.0b013e31829a6ce8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Insulin resistance in obesity is decreased after successful diet and exercise. Aerobic exercise training alone was evaluated as an intervention in subjects with the metabolic syndrome. METHODS Eighteen nondiabetic, sedentary subjects, 11 with the metabolic syndrome, participated in 8 wk of increasing intensity stationary cycle training. RESULTS Cycle training without weight loss did not change insulin resistance in metabolic syndrome subjects or sedentary control subjects. Maximal oxygen consumption (V·O 2max), activated muscle AMP-dependent kinase, and muscle mitochondrial marker ATP synthase all increased. Strength, lean body mass, and fat mass did not change. The activated mammalian target of rapamycin was not different after training. Training induced a shift in muscle fiber composition in both groups but in opposite directions. The proportion of type 2× fibers decreased with a concomitant increase in type 2a mixed fibers in the control subjects, but in metabolic syndrome, type 2× fiber proportion increased and type 1 fibers decreased. Muscle fiber diameters increased in all three fiber types in metabolic syndrome subjects. Muscle insulin receptor expression increased in both groups, and GLUT4 expression increased in the metabolic syndrome subjects. The excess phosphorylation of insulin receptor substrate 1 (IRS-1) at Ser337 in metabolic syndrome muscle tended to increase further after training in spite of a decrease in total IRS-1. CONCLUSIONS In the absence of weight loss, the cycle training of metabolic syndrome subjects resulted in enhanced mitochondrial biogenesis and increased the expression of insulin receptors and GLUT4 in muscle but did not decrease the insulin resistance. The failure for the insulin signal to proceed past IRS-1 tyrosine phosphorylation may be related to excess serine phosphorylation at IRS-1 Ser337, and this is not ameliorated by 8 wk of endurance exercise training.
Collapse
Affiliation(s)
- Charles A Stuart
- 1Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, Johnson City, TN; 2Department of Exercise and Sport Science, Clemmer College of Education, East Tennessee State University, Johnson City, TN; and 3Department of Allied Health, College of Clinical and Rehabilitative Health, East Tennessee State University, Johnson City, TN
| | | | | | | | | | | | | |
Collapse
|
25
|
Zhu Z, Jiang Z, Zhou J, Zhou D, Wang W, Zhao C, Zhen Z, Nanji AA. Involvement of insulin resistance in the protective effect of metformin against alcoholic liver injury. Alcohol Clin Exp Res 2014; 38:1510-9. [PMID: 24797033 DOI: 10.1111/acer.12418] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 02/11/2014] [Accepted: 03/12/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Alcoholic liver disease (ALD) continues to be a major cause of morbidity worldwide. The exact mechanisms for ALD pathogenesis are not fully understood. There is currently no known available drug for ALD. Previous studies have suggested that ethanol (EtOH)-induced hepatic insulin resistance, through the inhibition of adenosine monophosphate-activated protein kinase (AMPK) and the expression of adiponectin as well as downstream enzymes, contribute to the development of ALD. This study was to determine the effects of EtOH on AMPK activity as well as the protective effect of metformin. METHODS Forty male Wistar rats weighing 200 ± 20 g were randomized into 4 groups (n = 10) as follows: A = control group-rats received rodent chow; B = control + metformin group-rats received metformin (200 mg/kg/d intragastrically [IG]) at 21:00; C = EtOH group-rats were gavaged with alcohol of gradually increasing concentrations (30 to 60%, 5 to 9 g/kg/d) twice a day (9:00 and 16:00); D = EtOH + metformin group-rats received the same amount of EtOH as the rats in group C, and in addition received metformin (200 mg/kg/d IG) at 21:00. After 16 weeks, blood and liver samples were collected for further study. RESULTS Chronic EtOH consumption led to liver injury both histologically and biochemically accompanied by insulin resistance, reduced AMPK activity, and dysregulation of downstream enzymes. Decreased levels of circulating adiponectin and decreased expression of proliferator-activated receptor gamma coactivator-1α (PGC-1α) and peroxisome proliferator-activated receptors-α (PPAR-α) in the hepatic tissue were observed. Treatment with metformin attenuated the severity of liver injury, restored AMPK activity and normalized the expression of acetyl-CoA carboxylase and fatty acid synthase. In addition, metformin also increased the circulating adiponectin and liver adiponectin receptor 2 expression. Furthermore, PGC-1α and PPAR-α activities were also restored. CONCLUSIONS EtOH exposure induces hepatic insulin resistance. Metformin improved insulin resistance and reversed liver injury through the activation of AMPK and normalized adiponectin signaling making metformin a promising drug for the treatment of ALD.
Collapse
Affiliation(s)
- ZhanTao Zhu
- Department of Infectious disease , Third Hospital, Hebei Medical University, Shijiazhuang, China
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Mann S, Beedie C, Balducci S, Zanuso S, Allgrove J, Bertiato F, Jimenez A. Changes in insulin sensitivity in response to different modalities of exercise: a review of the evidence. Diabetes Metab Res Rev 2014; 30:257-68. [PMID: 24130081 DOI: 10.1002/dmrr.2488] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 09/10/2013] [Accepted: 10/08/2013] [Indexed: 11/12/2022]
Abstract
Type 2 diabetes is an increasingly prevalent condition with complications including blindness and kidney failure. Evidence suggests that type 2 diabetes is associated with a sedentary lifestyle, with physical activity demonstrated to increase glucose uptake and improve glycaemic control. Proposed mechanisms for these effects include the maintenance and improvement of insulin sensitivity via increased glucose transporter type four production. The optimal mode, frequency, intensity and duration of exercise for the improvement of insulin sensitivity are however yet to be identified. We review the evidence from 34 published studies addressing the effects on glycaemic control and insulin sensitivity of aerobic exercise, resistance training and both combined. Effect sizes and confidence intervals are reported for each intervention and meta-analysis presented. The quality of the evidence is tentatively graded, and recommendations for best practice proposed.
Collapse
Affiliation(s)
- S Mann
- UKactive Research Institute, University of Greenwich, Chatham Maritime, UK
| | | | | | | | | | | | | |
Collapse
|
27
|
Malin SK, Haus JM, Solomon TPJ, Blaszczak A, Kashyap SR, Kirwan JP. Insulin sensitivity and metabolic flexibility following exercise training among different obese insulin-resistant phenotypes. Am J Physiol Endocrinol Metab 2013; 305:E1292-8. [PMID: 24064339 PMCID: PMC3840211 DOI: 10.1152/ajpendo.00441.2013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Impaired fasting glucose (IFG) blunts the reversal of impaired glucose tolerance (IGT) after exercise training. Metabolic inflexibility has been implicated in the etiology of insulin resistance; however, the efficacy of exercise on peripheral and hepatic insulin sensitivity or substrate utilization in adults with IFG, IGT, or IFG + IGT is unknown. Twenty-four older (66.7 ± 0.8 yr) obese (34.2 ± 0.9 kg/m(2)) adults were categorized as IFG (n = 8), IGT (n = 8), or IFG + IGT (n = 8) according to a 75-g oral glucose tolerance test (OGTT). Subjects underwent 12-wk of exercise (60 min/day for 5 days/wk at ∼85% HRmax) and were instructed to maintain a eucaloric diet. A euglycemic hyperinsulinemic clamp (40 mU·m(2)·min(-1)) with [6,6-(2)H]glucose was used to determine peripheral and hepatic insulin sensitivity. Nonoxidative glucose disposal and metabolic flexibility [insulin-stimulated respiratory quotient (RQ) minus fasting RQ] were also assessed. Glucose incremental area under the curve (iAUCOGTT) was calculated from the OGTT. Exercise increased clamp-derived peripheral and hepatic insulin sensitivity more in adults with IFG or IGT alone than with IFG + IGT (P < 0.05). Exercise reduced glucose iAUCOGTT in IGT only (P < 0.05), and the decrease in glucose iAUCOGTT was inversely correlated with the increase in peripheral but not hepatic insulin sensitivity (P < 0.01). Increased clamp-derived peripheral insulin sensitivity was also correlated with enhanced metabolic flexibility, reduced fasting RQ, and higher nonoxidative glucose disposal (P < 0.05). Adults with IFG + IGT had smaller gains in clamp-derived peripheral insulin sensitivity and metabolic flexibility, which was related to blunted improvements in postprandial glucose. Additional work is required to assess the molecular mechanism(s) by which chronic hyperglycemia modifies insulin sensitivity following exercise training.
Collapse
Affiliation(s)
- Steven K Malin
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | | | | | | | | | | |
Collapse
|
28
|
Malin SK, Hinnerichs KR, Echtenkamp BG, Evetovich TK, Engebretsen BJ. Effect of adiposity on insulin action after acute and chronic resistance exercise in non-diabetic women. Eur J Appl Physiol 2013; 113:2933-41. [PMID: 24072034 DOI: 10.1007/s00421-013-2725-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 09/06/2013] [Indexed: 01/12/2023]
Abstract
PURPOSE Obesity may attenuate metabolic health improvements following lifestyle interventions. However, the effect of adiposity on insulin action following resistance exercise in young non-diabetic women is unknown. The purpose of this study was to test the hypothesis that adiposity attenuates improvements in insulin sensitivity and glucose-stimulated insulin secretion (INS0-60/GLC0-60) after both acute resistance exercise (ARE) and progressive training (PRT). METHODS Twenty-six young non-diabetic women (21.2 ± 0.7 years) were randomly assigned to control (C; n = 7; BF 40.1 ± 2.1 %) or exercise groups: normal body fat (NBF; n = 8; BF 29.9 ± 2.3 %) and high body fat (HBF; n = 12; BF 48.2 ± 1.4 %). Acute whole-body exercises were performed at 60 % of 1-RM for three sets of 8-12 repetitions, and PRT was performed 3 days/week for 7 weeks. A 75 g OGTT was conducted before and after ARE and PRT to estimate insulin sensitivity (Matsuda index) and INS0-60/GLC0-60. Insulin area under the curve (AUC) was calculated using the trapezoidal model. RESULTS ARE had no statistical effect on insulin action across groups. Strength and fat-free mass (via DXA) increased after PRT in both NBF and HBF (p < 0.05), but only HBF women decreased BF (p < 0.01). HBF women were less insulin sensitive at baseline compared to NBF women (p < 0.05). Insulin sensitivity increased 95 % and INS0-60/GLC0-60 decreased 32 % following PRT in NBF, but not HBF or C (p < 0.05). After training, enhanced insulin sensitivity was inversely related to decreased INS0-60/GLC0-60 (r = -0.71, p < 0.001), fasting insulin (r = -0.71, p < 0.001), and insulin AUC (r = -0.85, p < 0.001). CONCLUSION Seven weeks of PRT increases insulin sensitivity and reduces glucose-stimulated insulin secretion in NBF, but not HBF women. Obesity attenuates exercise-induced improvements in glucose regulation in young non-diabetic women.
Collapse
Affiliation(s)
- Steven K Malin
- Energy Metabolism Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA
| | | | | | | | | |
Collapse
|
29
|
Johannsen NM, Sparks LM, Zhang Z, Earnest CP, Smith SR, Church TS, Ravussin E. Determinants of the Changes in Glycemic Control with Exercise Training in Type 2 Diabetes: A Randomized Trial. PLoS One 2013; 8:e62973. [PMID: 23805175 PMCID: PMC3689775 DOI: 10.1371/journal.pone.0062973] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 03/24/2013] [Indexed: 12/26/2022] Open
Abstract
Aims To assess the determinants of exercise training-induced improvements in glucose control (HbA1C) including changes in serum total adiponectin and FFA concentrations, and skeletal muscle peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) protein content. Methods A sub-cohort (n = 35; 48% men; 74% Caucasian) from the HART-D study undertaking muscle biopsies before and after 9 months of aerobic (AT), resistance (RT), or combination training (ATRT). Results Changes in HbA1C were associated with changes in adiponectin (r = −0.45, P = 0.007). Participants diagnosed with type 2 diabetes for a longer duration had the largest increase in PGC-1α (r = 0.44, P = 0.008). Statistical modeling examining changes in HbA1C suggested that male sex (P = 0.05), non-Caucasian ethnicity (P = 0.02), duration of type 2 diabetes (r = 0.40; P<0.002) and changes in FFA (r = 0.36; P<0.004), adiponectin (r = −0.26; P<0.03), and PGC-1α (r = −0.28; P = 0.02) explain ∼65% of the variability in the changes in HbA1C. Conclusions Decreases in HbA1C after 9 months of exercise were associated with shorter duration of diabetes, lowering of serum FFA concentrations, increasing serum adiponectin concentrations and increasing skeletal muscle PGC-1α protein expression. Trial Registration ClinicalTrials.gov NCT00458133
Collapse
Affiliation(s)
- Neil M. Johannsen
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
- Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Lauren M. Sparks
- Translational Research Institute for Metabolism and Diabetes, Orlando, Florida, United States of America
| | - Zhengyu Zhang
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | | | - Steven R. Smith
- Sanford-Burnham Medical Research Institute, Orlando, Florida, United States of America
| | - Timothy S. Church
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | - Eric Ravussin
- Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
- * E-mail:
| |
Collapse
|
30
|
Stuart CA, McCurry MP, Marino A, South MA, Howell MEA, Layne AS, Ramsey MW, Stone MH. Slow-twitch fiber proportion in skeletal muscle correlates with insulin responsiveness. J Clin Endocrinol Metab 2013; 98:2027-36. [PMID: 23515448 PMCID: PMC3644602 DOI: 10.1210/jc.2012-3876] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The metabolic syndrome, characterized by central obesity with dyslipidemia, hypertension, and hyperglycemia, identifies people at high risk for type 2 diabetes. OBJECTIVE Our objective was to determine how the insulin resistance of the metabolic syndrome is related to muscle fiber composition. DESIGN Thirty-nine sedentary men and women (including 22 with the metabolic syndrome) had insulin responsiveness quantified using euglycemic clamps and underwent biopsies of the vastus lateralis muscle. Expression of insulin receptors, insulin receptor substrate-1, glucose transporter 4, and ATP synthase were quantified with immunoblots and immunohistochemistry. PARTICIPANTS AND SETTING Participants were nondiabetic, metabolic syndrome volunteers and sedentary control subjects studied at an outpatient clinic. MAIN OUTCOME MEASURES Insulin responsiveness during an insulin clamp and the fiber composition of a muscle biopsy specimen were evaluated. RESULTS There were fewer type I fibers and more mixed (type IIa) fibers in metabolic syndrome subjects. Insulin responsiveness and maximal oxygen uptake correlated with the proportion of type I fibers. Insulin receptor, insulin receptor substrate-1, and glucose transporter 4 expression were not different in whole muscle but all were significantly less in the type I fibers of metabolic syndrome subjects when adjusted for fiber proportion and fiber size. Fat oxidation and muscle mitochondrial expression were not different in the metabolic syndrome subjects. CONCLUSION Lower proportion of type I fibers in metabolic syndrome muscle correlated with the severity of insulin resistance. Even though whole muscle content was normal, key elements of insulin action were consistently less in type I muscle fibers, suggesting their distribution was important in mediating insulin effects.
Collapse
MESH Headings
- ATP Synthetase Complexes/metabolism
- Adult
- Antigens, CD/metabolism
- Body Mass Index
- Diabetes Mellitus, Type 2/epidemiology
- Diabetes Mellitus, Type 2/etiology
- Female
- Glucose Transporter Type 4/metabolism
- Humans
- Insulin Receptor Substrate Proteins/metabolism
- Insulin Resistance
- Male
- Metabolic Syndrome/complications
- Metabolic Syndrome/metabolism
- Metabolic Syndrome/pathology
- Middle Aged
- Muscle Fibers, Fast-Twitch/enzymology
- Muscle Fibers, Fast-Twitch/metabolism
- Muscle Fibers, Fast-Twitch/pathology
- Muscle Fibers, Slow-Twitch/enzymology
- Muscle Fibers, Slow-Twitch/metabolism
- Muscle Fibers, Slow-Twitch/pathology
- Obesity/complications
- Quadriceps Muscle/enzymology
- Quadriceps Muscle/metabolism
- Quadriceps Muscle/pathology
- Receptor, Insulin/metabolism
- Risk
- Sedentary Behavior
- Tennessee/epidemiology
Collapse
Affiliation(s)
- Charles A Stuart
- Department of Internal Medicine, Quillen College of Medicine, East Tennessee State University, P.O. Box 70622, Johnson City, Tennessee 37614-0622, USA.
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Friedrichsen M, Mortensen B, Pehmøller C, Birk JB, Wojtaszewski JFP. Exercise-induced AMPK activity in skeletal muscle: role in glucose uptake and insulin sensitivity. Mol Cell Endocrinol 2013; 366:204-14. [PMID: 22796442 DOI: 10.1016/j.mce.2012.06.013] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 06/21/2012] [Indexed: 12/25/2022]
Abstract
The energy/fuel sensor 5'-AMP-activated protein kinase (AMPK) is viewed as a master regulator of cellular energy balance due to its many roles in glucose, lipid, and protein metabolism. In this review we focus on the regulation of AMPK activity in skeletal muscle and its involvement in glucose metabolism, including glucose transport and glycogen synthesis. In addition, we discuss the plausible interplay between AMPK and insulin signaling regulating these processes.
Collapse
Affiliation(s)
- Martin Friedrichsen
- Molecular Physiology Group, The August Krogh Centre, Department of Exercise and Sport Sciences, University of Copenhagen, Denmark
| | | | | | | | | |
Collapse
|
32
|
Jackson KC, Wohlers LM, Lovering RM, Schuh RA, Maher AC, Bonen A, Koves TR, Ilkayeva O, Thomson DM, Muoio DM, Spangenburg EE. Ectopic lipid deposition and the metabolic profile of skeletal muscle in ovariectomized mice. Am J Physiol Regul Integr Comp Physiol 2012. [PMID: 23193112 DOI: 10.1152/ajpregu.00428.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Disruptions of ovarian function in women are associated with increased risk of metabolic disease due to dysregulation of peripheral glucose homeostasis in skeletal muscle. Our previous evidence suggests that alterations in skeletal muscle lipid metabolism coupled with altered mitochondrial function may also develop. The objective of this study was to use an integrative metabolic approach to identify potential areas of dysfunction that develop in skeletal muscle from ovariectomized (OVX) female mice compared with age-matched ovary-intact adult female mice (sham). The OVX mice exhibited significant increases in body weight, visceral, and inguinal fat mass compared with sham mice. OVX mice also had significant increases in skeletal muscle intramyocellular lipids (IMCL) compared with the sham animals, which corresponded to significant increases in the protein content of the fatty acid transporters CD36/FAT and FABPpm. A targeted metabolic profiling approach identified significantly lower levels of specific acyl carnitine species and various amino acids in skeletal muscle from OVX mice compared with the sham animals, suggesting a potential dysfunction in lipid and amino acid metabolism, respectively. Basal and maximal mitochondrial oxygen consumption rates were significantly impaired in skeletal muscle fibers from OVX mice compared with sham animals. Collectively, these data indicate that loss of ovarian function results in increased IMCL storage that is coupled with alterations in mitochondrial function and changes in the skeletal muscle metabolic profile.
Collapse
Affiliation(s)
- Kathryn C Jackson
- Univ. of Maryland, School of Public Health, Dept. of Kinesiology, College Park, MD 20742, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Malin SK, Kirwan JP. Fasting hyperglycaemia blunts the reversal of impaired glucose tolerance after exercise training in obese older adults. Diabetes Obes Metab 2012; 14:835-41. [PMID: 22510250 PMCID: PMC3407343 DOI: 10.1111/j.1463-1326.2012.01608.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
AIM Lifestyle modification, consisting of exercise and weight loss, delays the progression from prediabetes to type 2 diabetes (T2D). However, no study has determined the efficacy of exercise training on glucose metabolism in the different prediabetes subtypes. METHODS Seventy-six older (65.1 ± 0.6 years) obese adults with impaired fasting glucose (IFG; n = 12), impaired glucose tolerance (IGT; n = 9) and combined glucose intolerance (IFG + IGT = CGI; n = 22) were compared with normal glucose tolerant (NGT; n = 15) and T2D (n = 18) groups after 12 weeks of exercise training (60 min/day for 5 days/week at ~85% HR(max)). An oral glucose tolerance test was used to assess glucose levels. Insulin sensitivity (IS; euglycaemic hyperinsulinaemic clamp at 40 mU/m(2)/min), β-cell function (glucose-stimulated insulin secretion corrected for IS), body composition (hydrostatic weighing/computed tomography scan) and cardiovascular fitness (treadmill VO(2) max) were also assessed. RESULTS Exercise training reduced weight and increased cardiovascular fitness (p < 0.05). Exercise training lowered fasting glucose levels in IFG, CGI and T2D (p < 0.05) and 2-h glucose levels in IGT, CGI and T2D (p < 0.05). However, 2-h glucose levels were not normalized in adults with CGI compared with IGT (p < 0.05). β-Cell function improved similarly across groups (p < 0.05). Although not statistically significant, IS increased approximately 40% in IFG and IGT, but only 17% in CGI. CONCLUSION The magnitude of improvement in glucose metabolism after 12 weeks of exercise training is not uniform across the prediabetes subtypes. Given the high risk of progressing to T2D, adults with CGI may require more aggressive therapies to prevent diabetes.
Collapse
Affiliation(s)
- Steven K. Malin
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - John P. Kirwan
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
- Department of Physiology & Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106
- Metabolic Translational Research Center, Endocrine and Metabolism Institute, Cleveland Clinic, Cleveland, OH, 44195
| |
Collapse
|