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Kranen SH, Oliveira RS, Bond B, Williams CA, Barker AR. The utility of the reperfusion rate of tissue oxygen saturation as a measure of vascular endothelial function in adolescents: reliability, validity and sensitivity. Front Physiol 2023; 14:1163474. [PMID: 37781222 PMCID: PMC10533909 DOI: 10.3389/fphys.2023.1163474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 08/17/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction: The near-infrared spectroscopy (NIRS)-derived reperfusion rate of tissue oxygen saturation (slope 2 StO2) may provide a surrogate measure of vascular function, however, this has yet to be examined in a paediatric population. This study investigated in adolescents: 1) the between-day reliability of NIRS-derived measurements; 2) the relationship between slope 2 StO2 and macro- (flow-mediated dilation, FMD) and microvascular (peak reactive hyperaemia, PRH) function; and 3) the effect of high-intensity interval exercise (HIIE) on slope 2 StO2, FMD, and PRH. Methods: Nineteen boys (13.3 ± 0.5 y) visited the laboratory on two occasions, separated by ∼ 1 week. On visit 1, participants underwent simultaneous assessment of brachial artery FMD and slope 2 StO2 and PRH on the internal face of the forearm. On visit 2, participants completed a bout of HIIE with slope 2 StO2, FMD and PRH measured pre-, immediately post- and 1.5 h post-exercise. Results: Slope 2 StO2 showed no mean bias (p = 0.18) and an intraclass correlation coefficient of 0.67 (p = 0.003) between visits. No significant correlation between slope 2 StO2 and FMD or PRH was observed on visit 1 (r = -0.04, p = 0.89 and r = -0.30, p = 0.23, respectively) or visit 2 pre-exercise (r = -0.28, p = 0.25 and r = -0.31, p = 0.20, respectively). Compared to pre-exercise, FMD decreased immediately post-exercise (p < 0.001) and then increased 1.5 h post-exercise (p < 0.001). No significant change was detected for slope 2 StO2 (p = 0.30) or PRH (p = 0.55) following HIIE. Conclusion: In adolescents, slope 2 StO2 can be measured reliably, however, it is not correlated with FMD or PRH and does not follow the acute time course of changes in FMD post-exercise. Hence, the use of slope 2 StO2 as a surrogate measure of vascular function in youth must be refuted.
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Affiliation(s)
- Sascha H. Kranen
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Ricardo S. Oliveira
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- Department of Physical Education, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Bert Bond
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Craig A. Williams
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Alan R. Barker
- Children’s Health and Exercise Research Centre, Public Health and Sports Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
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Brar PC. Can Surrogate Markers Help Define Cardiovascular Disease in Youth? Curr Atheroscler Rep 2023:10.1007/s11883-023-01101-6. [PMID: 37148462 DOI: 10.1007/s11883-023-01101-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2023] [Indexed: 05/08/2023]
Abstract
PURPOSE OF REVIEW Non-invasive measurements such as arterial stiffness serve as proxy surrogates for detection of early atherosclerosis and ASCVD risk stratification. These surrogate measurements are influenced by age, gender, and ethnicity and affected by the physiological changes of puberty and somatic growth in children and adolescents. RECENT FINDINGS There is no consensus of the ideal method to measure surrogate markers in youth (< 18 years of age), nor standardized imaging protocols for youth. Currently, pediatric normative data are available but not generalizable. In this review, we provide rationale on how currently used surrogates can help identify subclinical atherosclerosis in youth and affirm their role in identifying youth at risk for premature CVD.
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Kranen SH, Oliveira RS, Bond B, Williams CA, Barker AR. The effect of 4 weeks of high-intensity interval training and 2 weeks of detraining on cardiovascular disease risk factors in male adolescents. Exp Physiol 2023; 108:595-606. [PMID: 36855259 PMCID: PMC10103894 DOI: 10.1113/ep090340] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 01/31/2023] [Indexed: 03/02/2023]
Abstract
NEW FINDINGS What is the central question of this study? What is the effect of 4 weeks of high-intensity interval training (HIIT) and 2 weeks of detraining on vascular function and traditional cardiovascular disease (CVD) risk factors in male adolescents? What is the main finding and its importance? Four weeks of HIIT improved macrovascular function in adolescents. However, this training period did not measurably change microvascular function, body composition or blood biomarkers. Following 2 weeks of detraining, the improvement in flow-mediated dilatation (FMD) was lost. This highlights the importance of the continuation of regular exercise for the primary prevention of CVD. ABSTRACT High-intensity interval training (HIIT) represents an effective method to improve cardiometabolic health in adolescents. This study aimed to investigate the effect of 4 weeks of HIIT followed by 2 weeks of detraining on vascular function and traditional cardiovascular disease (CVD) risk factors in adolescent boys. Nineteen male adolescents (13.3 ± 0.5 years) were randomly allocated to either a training (TRAIN, n = 10) or control (CON, n = 9) group. Participants in TRAIN completed 4 weeks of HIIT running with three sessions per week. Macro- (flow-mediated dilatation, FMD) and microvascular (peak reactive hyperaemia, PRH) function, body composition (fat mass, fat free mass, body fat percentage) and blood biomarkers (glucose, insulin, total cholesterol, high- and low-density lipoprotein, triacylglycerol) were assessed pre-, 48 h post- and 2 weeks post-training for TRAIN and at equivalent time points for CON. Following training, FMD was significantly greater in TRAIN compared to CON (9.88 ± 2.40% and 8.64 ± 2.70%, respectively; P = 0.036) but this difference was lost 2 weeks after training cessation (8.22 ± 2.47% and 8.61 ± 1.99%, respectively; P = 0.062). No differences were detected between groups for PRH (P = 0.821), body composition (all P > 0.14) or blood biomarkers (all P > 0.18). In conclusion, 4 weeks of HIIT improved macrovascular function; however, this training period did not measurably change microvascular function, body composition or blood biomarkers. The reversal of the FMD improvement 2 weeks post-training highlights the importance of the continuation of regular exercise for the primary prevention of CVD.
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Affiliation(s)
- Sascha H. Kranen
- Children's Health and Exercise Research Centre, Public Health and Sports SciencesUniversity of Exeter Medical School, Faculty of Health and Life Sciences, University of ExeterExeterUK
| | - Ricardo S. Oliveira
- Children's Health and Exercise Research Centre, Public Health and Sports SciencesUniversity of Exeter Medical School, Faculty of Health and Life Sciences, University of ExeterExeterUK
- Department of Physical EducationFederal University of Rio Grande do NorteNatalBrazil
| | - Bert Bond
- Children's Health and Exercise Research Centre, Public Health and Sports SciencesUniversity of Exeter Medical School, Faculty of Health and Life Sciences, University of ExeterExeterUK
| | - Craig A. Williams
- Children's Health and Exercise Research Centre, Public Health and Sports SciencesUniversity of Exeter Medical School, Faculty of Health and Life Sciences, University of ExeterExeterUK
| | - Alan R. Barker
- Children's Health and Exercise Research Centre, Public Health and Sports SciencesUniversity of Exeter Medical School, Faculty of Health and Life Sciences, University of ExeterExeterUK
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Chee AJY, Ho CK, Yiu BYS, Yu ACH. Time-Resolved Wall Shear Rate Mapping Using High-Frame-Rate Ultrasound Imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2022; 69:3367-3381. [PMID: 36343007 DOI: 10.1109/tuffc.2022.3220560] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In atherosclerosis, low wall shear stress (WSS) is known to favor plaque development, while high WSS increases plaque rupture risk. To improve plaque diagnostics, WSS monitoring is crucial. Here, we propose wall shear imaging (WASHI), a noninvasive contrast-free framework that leverages high-frame-rate ultrasound (HiFRUS) to map the wall shear rate (WSR) that relates to WSS by the blood viscosity coefficient. Our method measures WSR as the tangential flow velocity gradient along the arterial wall from the flow vector field derived using a multi-angle vector Doppler technique. To improve the WSR estimation performance, WASHI semiautomatically tracks the wall position throughout the cardiac cycle. WASHI was first evaluated with an in vitro linear WSR gradient model; the estimated WSR was consistent with theoretical values (an average error of 4.6% ± 12.4 %). The framework was then tested on healthy and diseased carotid bifurcation models. In both scenarios, key spatiotemporal dynamics of WSR were noted: 1) oscillating shear patterns were present in the carotid bulb and downstream to the internal carotid artery (ICA) where retrograde flow occurs; and 2) high WSR was observed particularly in the diseased model where the measured WSR peaked at 810 [Formula: see text] due to flow jetting. We also showed that WASHI could consistently track arterial wall motion to map its WSR. Overall, WASHI enables high temporal resolution mapping of WSR that could facilitate investigations on causal effects between WSS and atherosclerosis.
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Tallon CM, Talbot JS, Smith KJ, Lewis N, Nowak-Flück D, Stembridge M, Ainslie P, McManus AM. Dynamic onset response of the internal carotid artery to hypercapnia is blunted in children compared with adults. Physiol Rep 2022; 10:e15406. [PMID: 36017901 PMCID: PMC9413871 DOI: 10.14814/phy2.15406] [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: 04/18/2022] [Revised: 06/24/2022] [Accepted: 07/14/2022] [Indexed: 11/24/2022] Open
Abstract
Intracranial blood velocity reactivity to a steady‐state hypercapnic stimulus has been shown to be similar in children and adults, but the onset response to hypercapnia is slower in the child. Given the vasodilatory effect of hypercapnia on the cerebrovasculature, assessment of vessel diameter, and blood flow are vital to fully elucidate whether the temporal hypercapnic response differs in children versus adults. Assessment of internal carotid artery (ICA) vessel diameter (ICAd), blood velocity (ICAv), volumetric blood flow (QICA), and shear rate (ICASR) in response to a 4 min hypercapnic challenge was completed in children (n = 14, 8 girls; 9.8 ± 0.7 years) and adults (n = 17, 7 females; 24.7 ± 1.8 years). The dynamic onset responses of partial pressure of end‐tidal CO2 (PETCO2), QICA, ICAv, and ICASR to hypercapnia were modeled, and mean response time (MRT) was computed. Following 4 min of hypercapnia, ICA reactivity and ICAd were comparable between the groups. Despite a similar MRT in PETCO2 in children and adults, children had slower QICA (children 108 ± 60 s vs. adults 66 ± 37 s; p = 0.023), ICAv (children 120 ± 52 s vs. adults 52 ± 31 s; p = 0.001), and ICASR (children 90 ± 27 s vs. adults 47 ± 36 s; p = 0.001) MRTs compared with adults. This is the first study to show slower hypercapnic hyperemic kinetic responses of the ICA in children. The mechanisms determining these differences and the need to consider the duration of hypercapnic exposure when assessing CVR in children should be considered in future studies.
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Affiliation(s)
- Christine M Tallon
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Jack S Talbot
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Kurt J Smith
- Cerebrovascular Health, Exercise, and Environmental Research Sciences Laboratory, School of Exercise Science and Physical Health Education, University of Victoria, Victoria, British Columbia, Canada
| | - Nia Lewis
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Daniela Nowak-Flück
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Mike Stembridge
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, Wales, UK
| | - Philip Ainslie
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Ali M McManus
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
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The effects of HIIT compared to MICT on endothelial function and hemodynamics in postmenopausal females. J Sci Med Sport 2022; 25:364-371. [DOI: 10.1016/j.jsams.2022.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 11/17/2022]
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Kranen SH, Oliveira RS, Bond B, Williams CA, Barker AR. The acute effect of high- and moderate-intensity interval exercise on vascular function before and after a glucose challenge in adolescents. Exp Physiol 2020; 106:913-924. [PMID: 33369795 DOI: 10.1113/ep089159] [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: 10/09/2020] [Accepted: 12/16/2020] [Indexed: 02/01/2023]
Abstract
NEW FINDINGS What is the central question of this study? What is the effect of high-intensity and moderate-intensity interval running on macro- and microvascular function in a fasted state and following a glucose challenge in adolescents? What is the main finding and its importance? Both macro- and microvascular function were improved after interval running independent of intensity. This finding shows that the intermittent exercise pattern and its associated effect on shear are important for vascular benefits. In adolescents, macrovascular function was enhanced after an acute glucose load. However, the effect of chronic glucose consumption on vascular function remains to be elucidated. ABSTRACT Interventions targeting vascular function in youth are an important strategy for the primary prevention of cardiovascular diseases. This study examined, in adolescents, the effect of high-intensity interval running (HIIR) and moderate-intensity interval running (MIIR) on vascular function in a fasted state and postprandially after a glucose challenge. Fifteen adolescents (13 male, 13.9 ± 0.6 years) completed the following conditions on separate days in a counterbalanced order: (1) 8 × 1 min HIIR interspersed with 75 s recovery; (2) distance-matched amount of 1 min MIIR interspersed with 75 s recovery; and (3) rest (CON). Macro- (flow-mediated dilatation, FMD) and microvascular (peak reactive hyperaemia, PRH) function were assessed immediately before and 90 min after exercise/rest. Participants underwent an oral glucose tolerance test (OGTT) 2 h after exercise/rest before another assessment of vascular function 90 min after the OGTT. Following exercise, both HIIR and MIIR increased FMD (P = 0.02 and P = 0.03, respectively) and PRH (P = 0.04, and P = 0.01, respectively) with no change in CON (FMD: P = 0.51; PRH: P = 0.16) and no significant differences between exercise conditions. Following the OGTT, FMD increased in CON (P < 0.01) with no changes in HIIR and MIIR (both P > 0.59). There was no change in PRH after the OGTT (all P > 0.40). In conclusion, vascular function is improved after interval running independent of intensity in adolescents. Acute hyperglycaemia increased FMD, but prior exercise did not change vascular function after the OGTT in youth.
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Affiliation(s)
- Sascha H Kranen
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Ricardo S Oliveira
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.,Department of Physical Education, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Bert Bond
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Craig A Williams
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Alan R Barker
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
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Nowak KL, Jovanovich A, Farmer-Bailey H, Bispham N, Struemph T, Malaczewski M, Wang W, Chonchol M. Vascular Dysfunction, Oxidative Stress, and Inflammation in Chronic Kidney Disease. ACTA ACUST UNITED AC 2020; 1:501-509. [PMID: 33305290 DOI: 10.34067/kid.0000962019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Background Increased arterial stiffness and vascular endothelial dysfunction are important nontraditional cardiovascular risk factors evident in patients with CKD. Vascular oxidative stress and inflammation may contribute to vascular dysfunction in CKD, but direct evidence is lacking. Methods We assessed carotid-femoral pulse-wave velocity (arterial stiffness) and brachial artery flow-mediated dilation (vascular endothelial function) in participants with moderate-to-severe CKD (eGFR 15-59 ml/min per 1.73 m2) and in healthy controls. Change in brachial artery flow-mediated dilation after an acute infusion of ascorbic acid to inhibit vascular oxidative stress (versus saline) was also measured. Protein expression of vascular endothelial cells collected from a peripheral vein and ELISAs to assess circulating markers were also performed. Results A total of 64 participants with CKD (mean±SD, 65±8 years) and 17 healthy controls (60±5 years) were included. Carotid-femoral pulse-wave velocity was greater in participants with CKD compared with healthy controls (1071±336 versus 732±128 cm/s; P<0.001). Brachial artery flow-mediated dilation was lower in participants with CKD compared with healthy controls (3.5%±2.8% versus 5.5%±3.2%; P=0.02). Circulating inflammation markers (C-reactive protein and IL-6) were elevated in the CKD group (P≤0.02). Endothelial cell protein expression of NADPH (intensity versus human umbilical vein endothelial cell control, 1.48±0.28 versus 1.25±0.31; P=0.05) was greater in participants with CKD. However, ascorbic acid significantly improved brachial artery flow-mediated dilation in control participants (saline, 5.5±3.2; ascorbic acid, 6.8±3.6); as compared with participants with CKD (saline, 3.5±2.8; ascorbic acid, 3.6±3.2) (group×condition interaction P=0.04), suggesting vascular oxidative stress could not be overcome with ascorbic acid in participants with CKD. Conclusions Vascular oxidative stress is present in CKD, which cannot be overcome with acute infusion of ascorbic acid.
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Affiliation(s)
- Kristen L Nowak
- Anschutz Medical Campus, University of Colorado, Aurora, Colorado
| | - Anna Jovanovich
- Anschutz Medical Campus, University of Colorado, Aurora, Colorado.,Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado
| | | | - Nina Bispham
- Anschutz Medical Campus, University of Colorado, Aurora, Colorado
| | - Taylor Struemph
- Anschutz Medical Campus, University of Colorado, Aurora, Colorado
| | | | - Wei Wang
- Anschutz Medical Campus, University of Colorado, Aurora, Colorado
| | - Michel Chonchol
- Anschutz Medical Campus, University of Colorado, Aurora, Colorado
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9
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Weston ME. "To measure is to know": no relationship between cerebrovascular and peripheral shear-mediated dilation in young adults. J Physiol 2020; 599:1035-1036. [PMID: 33043460 DOI: 10.1113/jp280784] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/09/2020] [Indexed: 11/08/2022] Open
Affiliation(s)
- Max E Weston
- Children's Health and Exercise Research Centre, Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom.,Physiology and Ultrasound Laboratory in Science and Exercise, School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia
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10
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Li L, Lyall GK, Martinez-Blazquez JA, Vallejo F, A Tomas-Barberan F, Birch KM, Boesch C. Blood Orange Juice Consumption Increases Flow-Mediated Dilation in Adults with Overweight and Obesity: A Randomized Controlled Trial. J Nutr 2020; 150:2287-2294. [PMID: 32510144 DOI: 10.1093/jn/nxaa158] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/23/2020] [Accepted: 05/12/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Epidemiological studies have indicated an inverse association between citrus fruit consumption and cardiovascular disease (CVD) risk. There is, however, a paucity of data concerning effects of blood orange juice (BOJ) intake on endothelial function and cardiovascular risk biomarkers. OBJECTIVES We examined short-term effects of BOJ on endothelial function, blood pressure, lipid profile, and inflammatory markers in healthy participants of European origin who were overweight or obese. METHODS In a randomized, controlled, single-blind, crossover trial, 15 men and women (age: 28.7 ± 6.5 y; BMI: 28.3 ± 3.1 kg/m2) consumed BOJ or a sugar-matched control drink (CD) (200 mL twice daily) for 2 wk with a washout period of 1 wk. Endothelial function, measured as flow-mediated dilation (FMD) (primary outcome), and the secondary outcomes blood pressure, anthropometric measures, lipid profile, inflammatory markers, markers of vasodilation and vasoconstriction, and urinary flavanone metabolites were evaluated prior to and at the end of each treatment period following an overnight fast. Changes between treatments over time were assessed using repeated-measures ANOVA. RESULTS The results demonstrate a significant increase in FMD following BOJ consumption (pre: 8.15% ± 2.92%; post: 10.2% ± 3.31%; P = 0.002) compared with CD (pre: 8.11% ± 2.52%; post: 7.77% ± 2.43%; time × treatment interaction: P = 0.001). Concurrent significant increases in urinary hesperetin-3'-glucuronide and hesperetin-7-glucuronide were observed following BOJ supplementation only (time × treatment interaction: P ≤ 0.01). Baseline blood pressure, lipid profile, high-sensitivity C-reactive protein, and endothelin-1 were generally within healthy ranges and unaffected by the intervention. CONCLUSIONS A 2-wk consumption of BOJ exerted favorable effects on endothelial function in healthy women and men who were overweight or obese, which is likely mediated by the combined actions of anthocyanin and flavanone metabolites on mechanisms that contribute to enhancing NO bioavailability. This trial was registered at clinicaltrials.gov as NCT03611114.
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Affiliation(s)
- Lu Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing, China.,School of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom
| | - Gemma K Lyall
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - J Alberto Martinez-Blazquez
- Quality, Safety and Bioactivity of Plant Foods, Centre for Soil Science and Applied Biology-Spanish Council for Scientific Resarch (CEBAS-CSIC), Murcia, Spain
| | - Fernando Vallejo
- Quality, Safety and Bioactivity of Plant Foods, Centre for Soil Science and Applied Biology-Spanish Council for Scientific Resarch (CEBAS-CSIC), Murcia, Spain
| | - Francisco A Tomas-Barberan
- Quality, Safety and Bioactivity of Plant Foods, Centre for Soil Science and Applied Biology-Spanish Council for Scientific Resarch (CEBAS-CSIC), Murcia, Spain
| | - Karen M Birch
- School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Christine Boesch
- School of Food Science and Nutrition, University of Leeds, Leeds, United Kingdom
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11
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Smiljanec K, Mbakwe AU, Ramos-Gonzalez M, Pohlig RT, Lennon SL. Antioxidant cocktail following a high-sodium meal does not affect vascular function in young, healthy adult humans: a randomized controlled crossover trial. Nutr Res 2020; 79:13-22. [PMID: 32610254 DOI: 10.1016/j.nutres.2020.05.011] [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: 02/27/2020] [Revised: 05/06/2020] [Accepted: 05/18/2020] [Indexed: 02/06/2023]
Abstract
Chronic high sodium intake is a risk factor for cardiovascular disease as it impairs vascular function through an increase in oxidative stress. The objective of this study was to investigate the acute effects of a high-sodium meal (HSM) and antioxidant (AO) cocktail on vascular function. We hypothesized that a HSM would impair endothelial function, and increase arterial stiffness and wave reflection, while ingestion of the AO cocktail would mitigate this response. Healthy adults ingested either an AO cocktail (vitamin C, E, alpha-lipoic acid) or placebo (PLA) followed by a HSM (1500 mg) in a randomized crossover blinded design. Blood pressure (BP), endothelial function (flow-mediated dilation; FMD) and measures of arterial stiffness (pulse wave velocity; PWV) and wave reflection (augmentation index; AIx) were made at baseline and 30, 60, 90, and 120 min after meal consumption. Forty-one participants (20M/21W; 24 ± 1 years; BMI 23.4 ± 0.4 kg/m2) completed the study. Mean BP increased at 120 min relative to 60 min (60 min: 79 ± 1; 120 min: 81 ± 1 mmHg; time effect P = .01) but was not different between treatments (treatment × time interaction P = .32). AIx decreased from baseline (time effect P < .001) but was not different between treatments (treatment × time interaction P = .31). PWV (treatment × time interaction, P = .91) and FMD (treatment × time interaction P = .65) were also not different between treatments. In conclusion, a HSM does not acutely impair vascular function suggesting young healthy adults can withstand the acute impact of sodium on the vasculature and therefore, the AO cocktail is not necessary to mitigate the response.
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Affiliation(s)
- Katarina Smiljanec
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE.
| | - Alexis U Mbakwe
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE.
| | | | - Ryan T Pohlig
- Biostatistics Core Facility, University of Delaware, STAR, Newark, DE.
| | - Shannon L Lennon
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE.
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12
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Jin W, Chowienczyk P, Alastruey J. An in silico simulation of flow-mediated dilation reveals that blood pressure and other factors may influence the response independent of endothelial function. Am J Physiol Heart Circ Physiol 2020; 318:H1337-H1345. [PMID: 32302493 DOI: 10.1152/ajpheart.00703.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Endothelial dysfunction is thought to underpin atherosclerotic cardiovascular disease. The most widely used in vivo test of endothelial function is flow-mediated dilation (FMD). However, the results of FMD may be subject to some confounding factors that are not fully understood. We investigated potential biophysical confounding factors that could cause a disassociation between FMD and true endothelial cell shear stress response (the release of endothelium-dependent relaxing factors in response to wall shear stress). Arterial hemodynamics during FMD was simulated using a novel computational modeling approach. The model included an endothelial response function relating changes in wall shear stress to changes in local vascular stiffness in the arm arteries and accounted for vascular stiffening with increasing blood pressure. The hemodynamic effects of cuff inflation and deflation were modeled by prescribing intraluminal arterial pressure changes and peripheral vasodilation. Evolution of arterial diameter and flow velocity during FMD was assessed by comparison against in vivo data. Our model revealed that vasoconstriction occurring immediately after cuff deflation is independent of endothelial response function and entirely caused by the change in transmural pressure along conduit arteries. Moreover, for the same endothelial response function model, FMD values increased exponentially with increasing peak flow velocity, decreased linearly with increasing arterial stiffness at a rate of 0.95%/MPa, and increased linearly with increasing central blood pressure at a rate of 0.22%/mmHg. Dependence of FMD on confounding factors, such as arterial stiffness and blood pressure, suggests that the current FMD test may not reflect the true endothelial cell response.NEW & NOTEWORTHY First, a novel computational model simulating arterial hemodynamics during flow-mediated dilation (FMD) was proposed. Second, the model was used to explain why FMD may be influenced by endothelium-independent factors, showing that FMD results are 1) partly masked by the vasoconstriction due to the change in transmural pressure and 2) affected by physiological factors (i.e., arterial stiffness and arterial blood pressure) that are difficult to eliminate due to their multiple interactions.
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Affiliation(s)
- Weiwei Jin
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Philip Chowienczyk
- British Heart Foundation Centre, Department of Clinical Pharmacology, St Thomas' Hospital, King's College London, London, United Kingdom
| | - Jordi Alastruey
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.,Institute of Personalized Medicine, Sechenov University, Moscow, Russia
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13
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Malin SK, Gilbertson NM, Eichner NZM, Heiston E, Miller S, Weltman A. Impact of Short-Term Continuous and Interval Exercise Training on Endothelial Function and Glucose Metabolism in Prediabetes. J Diabetes Res 2019; 2019:4912174. [PMID: 31976336 PMCID: PMC6954470 DOI: 10.1155/2019/4912174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/21/2019] [Accepted: 12/12/2019] [Indexed: 01/22/2023] Open
Abstract
INTRODUCTION The impact of interval (INT) vs. continuous (CONT) exercise training on endothelial function in relation to glucose metabolism prior to clinically meaningful weight loss is unknown in adults with prediabetes. METHODS Twenty-six subjects with prediabetes (60 ± 1 y; 33 ± 1 kg/m2; 2-hr-PG OGTT: 145 ± 7 mg/dl) were randomized to 60 min of CONT (n = 12; 70% of HRpeak) or work-matched INT exercise training (n = 14; alternating 3 min at 90 and 50% HRpeak) for 2 weeks. Aerobic fitness (VO2peak) and body composition (bioelectrical impedance) were assessed before and after training. Flow-mediated dilation (FMD) was measured during a 2 h 75 g OGTT (0, 60, and 120 min) to assess endothelial function. Postprandial FMD was calculated as incremental area under the curve (iAUC). Glucose tolerance and insulin were also calculated by iAUC. Fasting plasma VCAM, ICAM, and hs-CRP were also assessed as indicators of vascular/systemic inflammation. RESULTS Both interventions increased VO2peak (P = 0.002) but had no effect on body fat (P = 0.20). Although both treatments improved glucose tolerance (P = 0.06) and insulin iAUC (P = 0.02), VCAM increased (P = 0.01). There was no effect of either treatment on ICAM, hs-CRP, or fasting as well as postprandial FMD. However, 57% of people improved fasting and iAUC FMD following CONT compared with only 42% after INT exercise (each: P = 0.04). Elevated VCAM was linked to blunted fasting FMD after training (r = -0.38, P = 0.05). But, there was no correlation between fasting FMD or postprandial FMD with glucose tolerance (r = 0.17, P = 0.39 and r = 0.02, P = 0.90, respectively) or insulin iAUC following training (r = 0.34, P = 0.08 and r = 0.04, P = 0.83, respectively). CONCLUSION Endothelial function is not improved consistently after short-term training, despite improvements in glucose and insulin responses to the OGTT in obese adults with prediabetes.
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Affiliation(s)
- Steven K. Malin
- Department of Kinesiology, University of Virginia, Charlottesville, VA, USA
- Division of Endocrinology & Metabolism, Department of Medicine, University of Virginia, Charlottesville, VA, USA
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA
| | | | | | - Emily Heiston
- Department of Kinesiology, University of Virginia, Charlottesville, VA, USA
| | - Stephanie Miller
- Department of Kinesiology, University of Virginia, Charlottesville, VA, USA
| | - Arthur Weltman
- Department of Kinesiology, University of Virginia, Charlottesville, VA, USA
- Division of Endocrinology & Metabolism, Department of Medicine, University of Virginia, Charlottesville, VA, USA
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14
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Whisner CM, Angadi SS, Weltman NY, Weltman A, Rodriguez J, Patrie JT, Gaesser GA. Effects of Low-Fat and High-Fat Meals, with and without Dietary Fiber, on Postprandial Endothelial Function, Triglyceridemia, and Glycemia in Adolescents. Nutrients 2019; 11:nu11112626. [PMID: 31684015 PMCID: PMC6893531 DOI: 10.3390/nu11112626] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 10/09/2019] [Accepted: 10/17/2019] [Indexed: 01/05/2023] Open
Abstract
The consumption of fiber-rich foods may negate the deleterious effects of high-fat meals on postprandial triglyceridemia and endothelial function. Despite supportive data in adults, little is known about the effects of high-fat and high-fiber foods on cardiovascular health parameters in pediatric populations. In this crossover trial, male and female adolescents (n = 10; 14.1 + 2.6 years; range 10–17 years) consumed (1) low-fat, low-fiber, (2) low-fat, high-fiber, (3) high-fat, low-fiber, and (4) high-fat, high-fiber breakfast meals in randomized order, each following an overnight fast. Baseline and 4 h post-meal blood was obtained for determination of glucose, insulin and triglyceride concentrations. Endothelial function was assessed via brachial artery flow-mediated dilation (FMD). Postprandial FMD was not significantly changed after any meal. However, regression analyses revealed a significant inverse relationship between the change in 4 h triglyceride concentration and change in 4 h FMD for the high-fat, low-fiber meal (β = −0.087; 95% CI = −0.138 to −0.037; p = 0.001) that was no longer significant in the high-fat, high-fiber meal (β = −0.044; 95% CI = −0.117 to 0.029; p = 0.227). Interpretation of these analyses must be qualified by acknowledging that between-meal comparison revealed that the two regression lines were not statistically different (p = 0.226). Addition of high-fiber cereal to the high-fat meal also reduced 4 h postprandial triglyceride increases by ~50% (p = 0.056). A high-fiber breakfast cereal did not attenuate postprandial glucose and insulin responses after consumption of a low-fat meal. While further work is needed to confirm these results in larger cohorts, our findings indicate the potential importance of cereal fiber in blunting the inverse relationship between postprandial hypertriglyceridemia and FMD after consumption of a high-fat meal in adolescents.
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Affiliation(s)
- Corrie M Whisner
- College of Health Solutions, Arizona State University, 550 N Third St., Phoenix, AZ 85004, USA.
| | - Siddhartha S Angadi
- College of Health Solutions, Arizona State University, 550 N Third St., Phoenix, AZ 85004, USA.
| | - Nathan Y Weltman
- Department of Anesthesiology, Perioperative and Pain Management, Brigham and Women's Hospital, Boston, MA 02115, USA.
| | - Arthur Weltman
- Department of Kinesiology, University of Virginia, Charlottesville, VA 22903, USA.
| | | | - James T Patrie
- Department of Public Health, University of Virginia, Charlottesville, VA 22903, USA.
| | - Glenn A Gaesser
- College of Health Solutions, Arizona State University, 550 N Third St., Phoenix, AZ 85004, USA.
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15
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Femoral Artery Blood Flow and Microcirculatory Perfusion During Acute, Low-Level Functional Electrical Stimulation in Spinal Cord Injury. Am J Phys Med Rehabil 2019; 97:721-726. [PMID: 29672351 DOI: 10.1097/phm.0000000000000955] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Functional electrical stimulation (FES) may help to reduce the risk of developing macrovascular and microvascular complications in people with spinal cord injury. Low-intensity FES has significant clinical potential because this can be applied continuously throughout the day. This study examines the acute effects of low-intensity FES using wearable clothing garment on vascular blood flow and oxygen consumption in people with spinal cord injury. DESIGN This was a cross-sectional observation study. METHODS Eight participants with a motor complete spinal cord injury received four 3-min unilateral FES to the gluteal and hamstring muscles. Skin and deep femoral artery blood flow and oxygen consumption were measured at baseline and during each bout of stimulation. RESULTS Femoral artery blood flow increased by 18.1% with the application of FES (P = 0.02). Moreover, femoral artery blood flow increased further during each subsequent block of FES (P = 0.004). Skin perfusion did not change during an individual block of stimulation (P = 0.66). Skin perfusion progressively increased with each subsequent bout (P < 0.001). There was no change in femoral or skin perfusion across time in the nonstimulated leg (all P > 0.05). CONCLUSION Low-intensity FES acutely increased blood flow during stimulation, with a progressive increase across subsequent FES bouts. These observations suggest that continuous, low-intensity FES may represent a practical and effective strategy to improve perfusion and reduce the risk of vascular complications.
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16
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The Impact of Different Exercise Intensities on Vasodilation and Shear Rate Patterns in Children. Pediatr Exerc Sci 2019; 31:282-289. [PMID: 31177912 DOI: 10.1123/pes.2019-0003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/22/2019] [Accepted: 04/24/2019] [Indexed: 11/18/2022]
Abstract
PURPOSE The effect of exercise intensity on vasodilator function is poorly understood in children. The authors compared the acute effect of high-intensity interval exercise (HIIE) with moderate-intensity steady-state exercise (MISS) on postexercise vasodilation and shear patterns in 7- to 12- year-old children. METHODS Superficial femoral artery diameter, shear rates, and flow-mediated dilation were measured pre, immediately following (post), and 1 hour after (post60) HIIE (six 1-min sprints at 90% peak power [Wmax], with 1-min recovery) and MISS (15 min at 44% Wmax). RESULTS Baseline superficial femoral artery diameter increased similarly following both HIIE (pre 4.23 [0.41] mm, post 4.73 [0.56] mm) and MISS (pre 4.28 [0.56] mm, post 4.59 [0.64] mm), returning to preexercise values post60. Blood flow and antegrade shear rate were increased post HIIE and MISS, but to a greater extent, post HIIE (P < .05). Retrograde shear rate was attenuated post both exercise conditions and remained post60 (P < .001). There was a decline in flow-mediated dilation postexercise (HIIE Δ -2.9%; MISS Δ -2.4%), which was no longer apparent when corrected for baseline diameter. CONCLUSION Acute bouts of external work-matched HIIE or MISS exert a similar impact on shear-mediated conduit artery vasodilation and flow-mediated dilation in children, and this is reversed 1 hour after exercise.
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17
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Aizawa K, Ramalli A, Sbragi S, Tortoli P, Casanova F, Morizzo C, Thorn CE, Shore AC, Gates PE, Palombo C. Arterial wall shear rate response to reactive hyperaemia is markedly different between young and older humans. J Physiol 2019; 597:4151-4163. [PMID: 31245837 DOI: 10.1113/jp278310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/24/2019] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The vasodilatory response to reactive hyperaemia is impaired with advancing age, but it is unclear whether this is because of an altered wall shear rate (WSR) stimulus or an altered flow-mediated dilatation (FMD) response. Using new technology that allows detailed WSR measurement, we assessed the WSR-FMD response in healthy older people. Our data show that older people have a markedly altered and diminished WSR response to reactive hyperaemia compared to young people, but reduced WSR alone does not fully explain reduced FMD. In young people, WSR appears to be coupled to FMD but, by age ∼65 years, the arterial vasodilatory response has begun to uncouple from the WSR stimulus. These findings point to the importance and utility of comprehensively characterizing the WSR-FMD response when using reactive hyperaemia to assess vascular function, as well as giving new insight into the age-related alteration in vascular function. ABSTRACT The vasodilatory response to reactive hyperaemia is impaired with age, but it is unknown whether this is because of an altered wall shear rate (WSR) stimulus or an altered flow-mediated dilatation (FMD) response to the WSR stimulus. Inherent difficulties in measuring blood flow velocity close to the arterial wall have prevented detailed assessment of the WSR-FMD response. Using an enhanced multigate spectral Doppler ultrasound system (ultrasound advanced open platform), we aimed to produce new data on the WSR-FMD relationship in healthy older adults. Sixty healthy people, comprising 28 young (27.5 ± 5.5 years) and 32 older (64.9 ± 3.7 years) individuals, underwent FMD assessment. Raw data were post-processed using custom-designed software to obtain WSR and diameter parameters. The data revealed that older people have a much altered and diminished WSR response to reactive hyperaemia compared to younger people [e.g. WSR peak: 622 (571-673) vs. 443 (396-491) 1/s in young and older respectively; P < 0.05]. However, reduced WSR alone does not appear to fully explain the reduced FMD response in older people because associations between WSR and FMD were few and weak. This was in contrast to young adults, where associations were strong. We conclude that WSR during FMD is much altered and diminished in older people, and there appears to be an 'uncoupling' of WSR from FMD in older people that may reflect a loss of precision in the reactive hyperaemia stimulus-response relationship. These findings also point to the importance and utility of comprehensively characterizing the WSR-FMD response when using reactive hyperaemia to assess vascular function.
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Affiliation(s)
- Kunihiko Aizawa
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, Exeter, UK
| | - Alessandro Ramalli
- Department of Information Engineering, University of Florence, Florence, Italy.,Laboratory of Cardiovascular Imaging and Dynamics, Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Sara Sbragi
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Piero Tortoli
- Department of Information Engineering, University of Florence, Florence, Italy
| | - Francesco Casanova
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, Exeter, UK
| | - Carmela Morizzo
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Clare E Thorn
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, Exeter, UK
| | - Angela C Shore
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, Exeter, UK
| | - Phillip E Gates
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, Exeter, UK
| | - Carlo Palombo
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
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18
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Thijssen DHJ, Bruno RM, van Mil ACCM, Holder SM, Faita F, Greyling A, Zock PL, Taddei S, Deanfield JE, Luscher T, Green DJ, Ghiadoni L. Expert consensus and evidence-based recommendations for the assessment of flow-mediated dilation in humans. Eur Heart J 2019; 40:2534-2547. [DOI: 10.1093/eurheartj/ehz350] [Citation(s) in RCA: 338] [Impact Index Per Article: 67.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 06/13/2018] [Accepted: 05/24/2019] [Indexed: 12/18/2022] Open
Abstract
Abstract
Endothelial dysfunction is involved in the development of atherosclerosis, which precedes asymptomatic structural vascular alterations as well as clinical manifestations of cardiovascular disease (CVD). Endothelial function can be assessed non-invasively using the flow-mediated dilation (FMD) technique. Flow-mediated dilation represents an endothelium-dependent, largely nitric oxide (NO)-mediated dilatation of conduit arteries in response to an imposed increase in blood flow and shear stress. Flow-mediated dilation is affected by cardiovascular (CV) risk factors, relates to coronary artery endothelial function, and independently predicts CVD outcome. Accordingly, FMD is a tool for examining the pathophysiology of CVD and possibly identifying subjects at increased risk for future CV events. Moreover, it has merit in examining the acute and long-term impact of physiological and pharmacological interventions in humans. Despite concerns about its reproducibility, the available evidence shows that highly reliable FMD measurements can be achieved when specialized laboratories follow standardized protocols. For this purpose, updated expert consensus guidelines for the performance of FMD are presented, which are based on critical appraisal of novel technical approaches, development of analysis software, and studies exploring the physiological principles underlying the technique. Uniformity in FMD performance will (i) improve comparability between studies, (ii) contribute to construction of reference values, and (iii) offer an easy accessible and early marker of atherosclerosis that could complement clinical symptoms of structural arterial disease and facilitate early diagnosis and prediction of CVD outcomes.
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Affiliation(s)
- Dick H J Thijssen
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rosa Maria Bruno
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
- Institute of Clinical Physiology, National Research Council, Via Moruzzi 1, Pisa, Italy
| | - Anke C C M van Mil
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Sophie M Holder
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
| | - Francesco Faita
- Institute of Clinical Physiology, National Research Council, Via Moruzzi 1, Pisa, Italy
| | - Arno Greyling
- Department Nutrition & Health, Unilever Vlaardingen, Vlaardingen, The Netherlands
| | - Peter L Zock
- Department Nutrition & Health, Unilever Vlaardingen, Vlaardingen, The Netherlands
| | - Stefano Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - John E Deanfield
- Institute of Cardiovascular Sciences, University College of London, 1 St Martin le Grand, London, UK
| | - Thomas Luscher
- Royal Brompton and Harefield Hospitals, London University Heart Center, Sydney Street, London, UK
| | - Daniel J Green
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UK
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Perth, Australia
| | - Lorenzo Ghiadoni
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
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19
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Total brachial artery reactivity and first time incident coronary heart disease events in a longitudinal cohort study: The multi-ethnic study of atherosclerosis. PLoS One 2019; 14:e0211726. [PMID: 30969969 PMCID: PMC6457482 DOI: 10.1371/journal.pone.0211726] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 01/19/2019] [Indexed: 11/26/2022] Open
Abstract
Background Brachial artery reactivity (BAR) is usually determined as the maximum brachial artery diameter (BAD) following release of an occluding pressure cuff compared to a BAD before cuff inflation. BAD early after cuff deflation can also serve as baseline for estimating total brachial artery reactivity (TBAR). We investigate whether TBAR is associated with first time coronary heart disease events. Methods Participants of the Multi-Ethnic Study of Atherosclerosis (n = 5499) consisting of whites, African-Americans, Chinese and Hispanics were followed longitudinally for a mean of 12.5 years. Brachial artery ultrasound was performed following five minutes of cuff occlusion at the forearm. TBAR was estimated from BAD following cuff release as the difference between maximum and minimum brachial artery diameters divided by the minimum diameter multiplied by 100%. TBAR was added to multivariable Cox proportional hazards models with Framingham risk factors as predictors and time to first coronary heart disease event as outcome. Results Average TBAR was 9.7% (9.7 SD). Mean age was 61.7 years, 50.9% women. Increased TBAR was associated with lower risk of CHD events with a hazard rate of 0.78 per SD increase (95% C.I. 0.67, 0.91; p = 0.001). A TBAR below the median of 7.87% (Inter Quartile Range: 4.16%, 13.0%) was associated with a 31% lower risk of coronary heart disease event (Hazard Ratio: 0.69; 95% C.I.: 0.55, 0.87). Conclusion TBAR is an independent predictor of first time coronary heart disease events and is exclusively measured after release of a blood pressure occlusion cuff.
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20
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Morales‐Acuna F, Ochoa L, Valencia C, Gurovich AN. Characterization of blood flow patterns and endothelial shear stress during flow‐mediated dilation. Clin Physiol Funct Imaging 2019; 39:240-245. [DOI: 10.1111/cpf.12564] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/13/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Francisco Morales‐Acuna
- Department of Rehabilitation Sciences College of Health Sciences The University of Texas at El PasoEl Paso TX USA
| | - Luis Ochoa
- Department of Mechanical Engineering W.M. Keck Center for 3D Innovation The University of Texas at El Paso El Paso TX USA
| | - Carolina Valencia
- Department of Rehabilitation Sciences College of Health Sciences The University of Texas at El PasoEl Paso TX USA
| | - Alvaro N. Gurovich
- Department of Rehabilitation Sciences College of Health Sciences The University of Texas at El PasoEl Paso TX USA
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21
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Ramalli A, Aizawa K, Shore AC, Morizzo C, Palombo C, Lenge M, Tortoli P. Continuous Simultaneous Recording of Brachial Artery Distension and Wall Shear Rate: A New Boost for Flow-Mediated Vasodilation. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2019; 66:463-471. [PMID: 30582536 DOI: 10.1109/tuffc.2018.2889111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Vascular ultrasound has been extensively applied in the clinical setting to noninvasively assess the endothelial function by means of the so-called brachial artery flow mediated dilation (FMD). Despite the usefulness in large-scale epidemiological studies, this approach has revealed some pitfalls for assessing vascular physiology and health in individual subjects. Mainly, a reliable FMD examination should be based on the simultaneous and reliable measurement of both the stimulus, i.e., the wall shear rate (WSR), and the response, i.e., the diameter change. However, multiple technical, practical, and methodological challenges must be faced to meet this goal. In this work, we present the technical developments needed to implement a system to enable the extensive and reliable clinical ultrasound FMD examination. It integrates both a hardware part, i.e., an upgraded version of the ultrasound advanced open platform (ULA-OP), and a software part, i.e., a signal processing and data analysis platform. The system was applied for a two-center pilot clinical study on 35 young and healthy volunteers. Therefore, we present here the results of a statistical analysis on magnitude, time-course, and kinetic parameters of WSR and diameter trends that allowed us to accurately explore the vasodilatory response to the dynamic WSR changes. Our observations demonstrate that a direct and accurate estimation of WSR stimulus by multigate spectral Doppler allows understanding brachial artery vasodilatory response to reactive hyperemia. Drawing inferences on WSR stimulus from the diameter response along with an inaccurate estimation of WSR may cause further uncertainties for the accurate interpretation of the FMD response.
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22
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Holder SM, Brislane Á, Dawson EA, Hopkins ND, Hopman MTE, Cable NT, Jones H, Schreuder THA, Sprung VS, Naylor L, Maiorana A, Thompson A, Thijssen DHJ, Green DJ. Relationship Between Endothelial Function and the Eliciting Shear Stress Stimulus in Women: Changes Across the Lifespan Differ to Men. J Am Heart Assoc 2019; 8:e010994. [PMID: 30764688 PMCID: PMC6405684 DOI: 10.1161/jaha.118.010994] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/18/2018] [Indexed: 01/26/2023]
Abstract
Background Premenopausal women have a lower incidence of cardiovascular disease, which may partly be due to a protective effect of estrogen on endothelial function. Animal studies suggest that estrogen may also improve the relationship between shear rate ( SR ) and endothelial function. We aimed to explore the relationship between endothelial function (ie, flow-mediated dilation [ FMD ]) and SR (ie, SR area under the curve [ SRAUC ]) in women versus men, and between pre- versus postmenopausal women. Methods and Results Brachial artery FMD and SRAUC were measured in accordance with expert-consensus guidelines in 932 healthy participants who were stratified into young adults (18-40 years, 389 men, 144 women) and older adults (>40 years, 260 men, 139 women). Second, we compared premenopausal (n=173) and postmenopausal women (n=110). There was evidence of a weak correlation between SRAUC and FMD in all groups but older men, although there was variation in strength of outcomes. Further exploration using interaction terms (age-sex× SRAUC ) in linear regression revealed differential relationships with FMD (young women versus young men [β=-5.8-4, P=0.017] and older women [β=-5.9-4, P=0.049]). The correlation between SRAUC and FMD in premenopausal women ( r2=0.097) was not statistically different from that in postmenopausal women ( r2=0.025; Fisher P=0.30). Subgroup analysis using stringent inclusion criteria for health markers (n=505) confirmed a stronger FMD - SRAUC correlation in young women compared with young men and older women. Conclusions Evidence for a stronger relationship between endothelial function and the eliciting SR stimulus is present in young women compared with men. Estrogen may contribute to this finding, but larger healthy cohorts are required for conclusive outcomes.
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Affiliation(s)
- Sophie M. Holder
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Áine Brislane
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Ellen A. Dawson
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Nicola D. Hopkins
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Maria T. E. Hopman
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - N. Timothy Cable
- School of Sport, Exercise and Rehabilitation SciencesUniversity of BirminghamUnited Kingdom
| | - Helen Jones
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
| | - Tim H. A. Schreuder
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Victoria S. Sprung
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
- Department of Musculoskeletal Biology IIInstitute of Ageing and Chronic DiseaseUniversity of LiverpoolUnited Kingdom
| | - Louise Naylor
- School of Human Sciences (Exercise and Sport Science)The University of Western AustraliaCrawleyWestern AustraliaAustralia
| | - Andrew Maiorana
- School of Physiotherapy and Exercise ScienceCurtin UniversityPerthAustralia
- Allied Health Department & Advanced Heart Failure and Cardiac Transplant ServiceFiona Stanley HospitalPerthAustralia
| | - Andrew Thompson
- Wolfson Centre for Personalised MedicineUniversity of LiverpoolUnited Kingdom
| | - Dick H. J. Thijssen
- Research Institute for Sport and Exercise SciencesLiverpool John Moores UniversityLiverpoolUnited Kingdom
- Department of PhysiologyRadboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Daniel J. Green
- School of Human Sciences (Exercise and Sport Science)The University of Western AustraliaCrawleyWestern AustraliaAustralia
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23
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Contribution of systemic vascular reactivity to variability in pulse volume amplitude response during reactive hyperemia. Eur J Appl Physiol 2019; 119:753-760. [PMID: 30637458 DOI: 10.1007/s00421-018-04066-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 12/29/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE The aim of the present study was to investigate why the magnitude of reactive hyperemia (RH) observed by pulse volume amplitude (PVA) after arm occlusion differs greatly among study subjects. METHODS Healthy subjects (n = 12) in the age range of 22-30 years participated in this study. Vascular reactivity was assessed by measuring the changes in finger PVA simultaneously in the test (occluded arm) and control arm (contralateral non-occluded arm) using two separate Photoplethysmographic sensors. Short-term HRV was computed from simultaneously acquired lead II ECG signal to monitor the changes in cardiac sympathetic nervous activity. RESULTS The observed coefficient of variation for inter-subject variability in PVA response in test arm during second minute of RH was 115.3%. In the control arm, significantly reduced PVA was observed during the period of occlusion as well as RH. This observation was corroborated by simultaneously acquired short-term HRV which showed a significant rise in total power (p value < 0.005) and low-frequency (LF) power (p value < 0.05) during release of occlusion when compared to the baseline. A significant positive correlation (Spearman r = 0.33; p = 0.02) was observed between % change in PVA in the control arm and in the test arm for first 3 min of RH. CONCLUSIONS Sympathetic activation possibly plays an important role in mediating the inter-subject variability of vascular responses during reactive hyperemia which warrants simultaneous recording of both the test and the control arm responses during RH to accurately assess endothelial function.
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Nowicki A, Trawinski Z, Gambin B, Secomski W, Szubielski M, Parol M, Olszewski R. 20-MHz Ultrasound for Measurements of Flow-Mediated Dilation and Shear Rate in the Radial Artery. ULTRASOUND IN MEDICINE & BIOLOGY 2018; 44:1187-1197. [PMID: 29598961 DOI: 10.1016/j.ultrasmedbio.2018.02.011] [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: 05/04/2017] [Revised: 02/14/2018] [Accepted: 02/22/2018] [Indexed: 06/08/2023]
Abstract
A high-frequency scanning system consisting of a 20-MHz linear array transducer combined with a 20-MHz pulsed Doppler probe was introduced to evaluate the degree of radial artery flow-mediated dilation (FMD [%]) in two groups of patients after 5 min of controlled forearm ischemia followed by reactive hyperemia. In group I, comprising 27 healthy volunteers, FMD (mean ± standard deviation) was 15.26 ± 4.90% (95% confidence interval [CI]: 13.32%-17.20%); in group II, comprising 17 patients with chronic coronary artery disease, FMD was significantly less at 4.53 ± 4.11% (95% CI: 2.42%-6.64%). Specifically, the ratio FMD/SR (mean ± standard deviation), was equal to 5.36 × 10-4 ± 4.64 × 10-4 (95% CI: 3.54 × 10-4 to 7.18 × 10-4) in group I and 1.38 × 10-4 ± 0.89 × 10-4 (95% CI: 0.70 × 10-4 to 2.06 × 10-4) in group II. Statistically significant differences between the two groups were confirmed by a Wilcoxon-Mann-Whitney test for both FMD and FMD/SR (p <0.01). Areas under receiver operating characteristic curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal patients from those with chronic coronary artery disease.
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Affiliation(s)
- Andrzej Nowicki
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland.
| | - Zbigniew Trawinski
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland
| | - Barbara Gambin
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland
| | - Wojciech Secomski
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland
| | | | - Marzena Parol
- The John Paul II Western Hospital in Grodzisk Mazowiecki, Grodzisk Mazowiecki, Poland
| | - Robert Olszewski
- Department of Ultrasound, Institute of the Fundamental Technological Research of the Polish Academy of Sciences, Warsaw, Poland; Department of Geriatrics National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland
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25
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Peace A, van Mil A, Jones H, Thijssen DH. Similarities and Differences Between Carotid Artery and Coronary Artery Function. Curr Cardiol Rev 2018; 14:254-263. [PMID: 30198437 PMCID: PMC6300794 DOI: 10.2174/1573403x14666180910125638] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 09/03/2018] [Accepted: 09/04/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Cardiovascular Disease (CVD) remains one of the leading causes of morbidity and mortality. Strategies to predict development of CVD are therefore key in preventing and managing CVD. One stratergy in predicting CVD is by examining the role of traditional risk factors for CVD (e.g. age, sex, weight, blood pressure, blood lipids, blood glucose, smoking and physical activity). Although these measures are non-invasive and simple to perform, they provide limited information of CVD prediction. Directly examining functional characteristics of arteries that are involved in the pathophysiological changes that contribute to the development of CVD improve prediction of future CVD. Nevertheless, examining the function of arteries susceptible to atherosclortic changes, such as the coronary arteries, is invasive, expensive, and associated with high risk for complications. More accessible arteries can be used as a surrogate measure of coronary artery function. For example, the carotid artery may be a superior surrogate measure of coronary artery function given that, the carotid artery represents a central vessel that shows similarities in vasomotor function and anatomical structure with coronary arteries. CONCLUSION This review summarises the similarities between the carotid and coronary arteries, describes how both arteries respond to specific vasoactive stimuli, and discusses if the easily assessible carotid artery can provide information about vascular function (e.g. vasomotor reactivity to sympathetic stimulation) which is prognostic for future cardiovascular events. Finally, the impact of older age and lifestyle interventions (e.g. exercise training) on carotid artery function will be discussed.
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Affiliation(s)
| | | | | | - Dick H.J. Thijssen
- Address correspondence to this author at the Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Tom Reilly Building, Byrom Street L3 3AF, Liverpool, United Kingdom;
Tel: +441519046264; E-mail:
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26
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Bailey TG, Perissiou M, Windsor MT, Schulze K, Nam M, Magee R, Leicht AS, Green DJ, Greaves K, Golledge J, Askew CD. Effects of acute exercise on endothelial function in patients with abdominal aortic aneurysm. Am J Physiol Heart Circ Physiol 2017; 314:H19-H30. [PMID: 28939648 DOI: 10.1152/ajpheart.00344.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endothelial dysfunction is observed in patients with abdominal aortic aneurysm (AAA), who have increased risk of cardiovascular events and mortality. This study aimed to assess the acute effects of moderate- and higher-intensity exercise on endothelial function, as assessed by flow-mediated dilation (FMD), in AAA patients (74 ± 6 yr old, n = 22) and healthy adults (72 ± 5 yr old, n = 22). Participants undertook three randomized visits, including moderate-intensity continuous exercise [40% peak power output (PPO)], higher-intensity interval exercise (70% PPO), and a no-exercise control. Brachial artery FMD was assessed at baseline and at 10 and 60 min after each condition. Baseline FMD was lower [by 1.10% (95% confidence interval: 0.72-.81), P = 0.044] in AAA patients than in healthy adults. There were no group differences in FMD responses after each condition ( P = 0.397). FMD did not change after no-exercise control but increased by 1.21% (95% confidence interval: 0.69-1.73, P < 0.001) 10 min after moderate-intensity continuous exercise in both groups and returned to baseline after 60 min. Conversely, FMD decreased by 0.93% (95% confidence interval: 0.41-1.44, P < 0.001) 10 min after higher-intensity interval exercise in both groups and remained decreased after 60 min. We found that the acute response of endothelial function to exercise is intensity-dependent and similar between AAA patients and healthy adults. Our findings provide evidence that regular exercise may improve vascular function in AAA patients, as it does in healthy adults. Improved FMD after moderate-intensity exercise may provide short-term benefit. Whether the decrease in FMD after higher-intensity exercise represents an additional risk and/or a greater stimulus for vascular adaptation remains to be elucidated. NEW & NOTEWORTHY Abdominal aortic aneurysm patients have vascular dysfunction. We observed a short-term increase in vascular function after moderate-intensity exercise. Conversely, higher-intensity exercise induced a prolonged reduction in vascular function, which may be associated with both short-term increases in cardiovascular risk and signaling for longer-term vascular adaptation in abdominal aortic aneurysm patients.
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Affiliation(s)
- Tom G Bailey
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Maria Perissiou
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Mark T Windsor
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
| | - Karl Schulze
- Sunshine Vascular Clinic, Buderim, Queensland, Australia
| | - Michael Nam
- Sunshine Coast University Hospital, Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
| | - Rebecca Magee
- Sunshine Coast University Hospital, Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
| | - Anthony S Leicht
- Sport and Exercise Science, James Cook University, Townville, Queensland, Australia
| | - Daniel J Green
- School of Sport Science, Exercise, and Health, University of Western Australia, Crawley, Western Australia, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , United Kingdom
| | - Kim Greaves
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia.,Sunshine Coast University Hospital, Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
| | - Jonathan Golledge
- Queensland Research Centre for Peripheral Vascular Disease, College of Medicine and Dentistry, James Cook University , Townsville, Queensland , Australia.,Department of Vascular and Endovascular Surgery, Townsville Hospital, Townsville, Queensland, Australia
| | - Christopher D Askew
- VasoActive Research Group, School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, Australia
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Aizawa K, Sbragi S, Ramalli A, Tortoli P, Casanova F, Morizzo C, Thorn CE, Shore AC, Gates PE, Palombo C. Brachial artery vasodilatory response and wall shear rate determined by multigate Doppler in a healthy young cohort. J Appl Physiol (1985) 2017; 124:150-159. [PMID: 28935823 DOI: 10.1152/japplphysiol.00310.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Wall shear rate (WSR) is an important stimulus for the brachial artery flow-mediated dilation (FMD) response. However, WSR estimation near the arterial wall by conventional Doppler is inherently difficult. To overcome this limitation, we utilized multigate Doppler to accurately determine the WSR stimulus near the vessel wall simultaneously with the FMD response using an integrated FMD system [Ultrasound Advanced Open Platform (ULA-OP)]. Using the system, we aimed to perform a detailed analysis of WSR-FMD response and establish novel WSR parameters in a healthy young population. Data from 33 young healthy individuals (27.5 ± 4.9 yr, 19 females) were analyzed. FMD was assessed with reactive hyperemia using ULA-OP. All acquired raw data were postprocessed using custom-designed software to obtain WSR and diameter parameters. The acquired velocity data revealed that nonparabolic flow profiles within the cardiac cycle and under different flow states, with heterogeneity between participants. We also identified seven WSR magnitude and four WSR time-course parameters. Among them, WSR area under the curve until its return to baseline was the strongest predictor of the absolute ( R2 = 0.25) and percent ( R2 = 0.31) diameter changes in response to reactive hyperemia. For the first time, we identified mono- and biphasic WSR stimulus patterns within our cohort that produced different magnitudes of FMD response [absolute diameter change: 0.24 ± 0.10 mm (monophasic) vs. 0.17 ± 0.09 mm (biphasic), P < 0.05]. We concluded that accurate and detailed measurement of the WSR stimulus is important to comprehensively understand the FMD response and that this advance in current FMD technology could be important to better understand vascular physiology and pathology. NEW & NOTEWORTHY An estimation of wall shear rate (WSR) near the arterial wall by conventional Doppler ultrasound is inherently difficult. Using a recently developed integrated flow-mediated dilation ultrasound system, we were able to accurately estimate WSR near the wall and identified a number of novel WSR variables that may prove to be useful in the measurement of endothelial function, an important biomarker of vascular physiology and disease.
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Affiliation(s)
- Kunihiko Aizawa
- Diabetes and Vascular Medicine Research Centre, National Institute of Health Research Exeter Clinical Research Facility, University of Exeter Medical School , Exeter , United Kingdom
| | - Sara Sbragi
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa , Pisa , Italy
| | - Alessandro Ramalli
- Department of Information Engineering, University of Florence , Florence , Italy
| | - Piero Tortoli
- Department of Information Engineering, University of Florence , Florence , Italy
| | - Francesco Casanova
- Diabetes and Vascular Medicine Research Centre, National Institute of Health Research Exeter Clinical Research Facility, University of Exeter Medical School , Exeter , United Kingdom
| | - Carmela Morizzo
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa , Pisa , Italy
| | - Clare E Thorn
- Diabetes and Vascular Medicine Research Centre, National Institute of Health Research Exeter Clinical Research Facility, University of Exeter Medical School , Exeter , United Kingdom
| | - Angela C Shore
- Diabetes and Vascular Medicine Research Centre, National Institute of Health Research Exeter Clinical Research Facility, University of Exeter Medical School , Exeter , United Kingdom
| | - Phillip E Gates
- Diabetes and Vascular Medicine Research Centre, National Institute of Health Research Exeter Clinical Research Facility, University of Exeter Medical School , Exeter , United Kingdom
| | - Carlo Palombo
- Department of Surgical, Medical, Molecular Pathology and Critical Care Medicine, University of Pisa , Pisa , Italy
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Brar PC. Vascular phenotype of obese adolescents with prediabetes and/or Type 2 diabetes (T2DM): Review of the current literature. Diabetes Metab Syndr 2016; 10:250-256. [PMID: 27381966 DOI: 10.1016/j.dsx.2016.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 06/06/2016] [Indexed: 10/21/2022]
Affiliation(s)
- Preneet Cheema Brar
- Department of Pediatrics, Division of Pediatric Endocrinology, New York University School of Medicine, New York, NY, United States.
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29
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Malin SK, Rynders CA, Weltman JY, Roberts LJ, Barrett EJ, Weltman A. Endothelial function following glucose ingestion in adults with prediabetes: Role of exercise intensity. Obesity (Silver Spring) 2016; 24:1515-21. [PMID: 27221649 PMCID: PMC4925188 DOI: 10.1002/oby.21522] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 03/11/2016] [Accepted: 03/17/2016] [Indexed: 01/06/2023]
Abstract
OBJECTIVE To determine whether high intensity exercise (HIE) would improve endothelial function more than an isocaloric bout of moderate intensity exercise (MIE) following glucose ingestion in adults with prediabetes. METHODS Twelve subjects with prediabetes completed all three conditions: time-course matched control and isocaloric exercise (∼200 kcal) at moderate (MIE; at lactate threshold) and high intensity (HIE; 75% of difference between lactate threshold and VO2 peak). Brachial artery flow-mediated dilation (FMD) was measured before exercise (baseline), within 30 min postexercise, and 1 and 2 hr following a 75 g oral glucose tolerance test (OGTT). Plasma F2-isoprostanes were also assessed during the protocol (i.e., baseline to 2 hr OGTT) as a biomarker of oxidative stress. RESULTS MIE reduced postexercise F2-isoprostanesAUC compared with time-course matched control and HIE. Although exercise had no statistical effect on FMD postexercise or during the OGTT, elevations in FMDAUC after MIE and HIE were associated with reduced postexercise F2-isoprostanesAUC . CONCLUSIONS Exercise at either intensity had no effect on FMD immediately postexercise following glucose administration. However, individuals with reduced oxidative stress responses to exercise had greater exercise-induced improvement in FMD. Further work is required to identify the mechanism by which exercise alters oxidative stress to enhance endothelial function.
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Affiliation(s)
- Steven K. Malin
- Department of Kinesiology, University of Virginia, Charlottesville VA
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville VA
- Exercise Physiology Core Laboratory, University of Virginia, Charlottesville VA
| | - Corey A. Rynders
- Division of Geriatric Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Judy Y. Weltman
- Exercise Physiology Core Laboratory, University of Virginia, Charlottesville VA
| | - L. Jackson Roberts
- Department of Pharmacology and Medicine, Vanderbilt University, Nashville TN
| | - Eugene J. Barrett
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville VA
| | - Arthur Weltman
- Department of Kinesiology, University of Virginia, Charlottesville VA
- Division of Endocrinology and Metabolism, University of Virginia, Charlottesville VA
- Exercise Physiology Core Laboratory, University of Virginia, Charlottesville VA
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30
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Evanoff NG, Kelly AS, Steinberger J, Dengel DR. Peak shear and peak flow mediated dilation: a time-course relationship. JOURNAL OF CLINICAL ULTRASOUND : JCU 2016; 44:182-187. [PMID: 26689837 PMCID: PMC5884966 DOI: 10.1002/jcu.22324] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 09/23/2015] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
PURPOSE To explore the temporal relationship between brachial artery peak shear stress (Shear) and flow-mediated dilation (FMD) in children and adults. METHODS Shear and brachial artery diameter were tracked following reactive hyperemia in 122 children and 350 adults using sonographic imaging. RESULTS Peak Shear, Shear area under the curve (Shear(AUC)), and Peak FMD were significantly larger in children than in adults. The time to peak Shear (Shear(TTP)) and time to peak FMD (FMD(TTP)) were significantly lower in children, while there was no significant difference in time from Shear(TTP) to FMD(TTP) between children and adults. CONCLUSIONS Children have a lower shear stimulus and FMD response than adults, but the time interval separating these events is similar. These differences could be due to changes in vascular dynamics with age, including reduced smooth muscle cell responsiveness and other factors. Despite differences in timing, the interval from peak Shear to peak FMD was similar in children and adults.
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Affiliation(s)
- Nicholas G. Evanoff
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
| | - Aaron S. Kelly
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
- Department of Medicine, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Julia Steinberger
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
| | - Donald R. Dengel
- Laboratory of Integrative Human Physiology, School of Kinesiology, University of Minnesota, Minneapolis, Minnesota, 55455
- Department of Pediatrics, University of Minnesota Medical School, Minneapolis, Minnesota, 55455
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31
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Bruno RM, Ghiadoni L, Pratali L. Vascular adaptation to extreme conditions: The role of hypoxia. Artery Res 2016. [DOI: 10.1016/j.artres.2016.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Meyer ML, Tepper PG, Barinas-Mitchell E, Korytkowski MT, Talbott EO. Varying patterns of brachial artery flow-mediated dilatation in women with polycystic ovary syndrome and controls: An application of the group-based trajectory modeling. JOURNAL OF CLINICAL ULTRASOUND : JCU 2016; 44:46-54. [PMID: 26177749 PMCID: PMC4890544 DOI: 10.1002/jcu.22280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 04/14/2015] [Accepted: 05/18/2015] [Indexed: 06/04/2023]
Abstract
PURPOSE To identify changing patterns of absolute change in brachial artery lumen diameter (LD) after reactive hyperemia in women with polycystic ovary syndrome (PCOS) and controls and to quantify the association of PCOS status and participants' factors with these patterns. METHODS Brachial flow-mediated dilation was measured in 128 women with PCOS and 148 controls aged 30-60 years. Group-based trajectory modeling was used to investigate absolute change in LD every 30 seconds for 2 minutes after occluding cuff deflation. Multinomial logistic regression was used to identify factors associated with trajectories. RESULTS Three patterns emerged, namely nondilators (42.2%), dilators (44.6%), and enhanced dilators (13.0%). The proportion of women with PCOS did not differ across groups. Independently of age and PCOS status, larger baseline LD (odds ratio; 95% confidence interval: 2.51; 1.29, 4.89) and lower insulin levels (0.70; 0.52, 0.93) were associated with nondilators rather than with dilators. Higher total cholesterol was associated with dilators in women with PCOS but with nondilators in controls. CONCLUSIONS Trajectory modeling identified distinct patterns of change in LD and factors associated with the endothelial response. This method may be a useful tool to understand the brachial flow-mediated vasodilator response.
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Affiliation(s)
- Michelle L Meyer
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Ping G Tepper
- Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Emma Barinas-Mitchell
- Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
| | - Mary T Korytkowski
- Division of Endocrinology and Metabolism, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Evelyn O Talbott
- Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
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BOND BERT, HIND SIOBHAN, WILLIAMS CRAIGA, BARKER ALANR. The Acute Effect of Exercise Intensity on Vascular Function in Adolescents. Med Sci Sports Exerc 2015; 47:2628-35. [DOI: 10.1249/mss.0000000000000715] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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McManus AM, Ainslie PN, Green DJ, Simair RG, Smith K, Lewis N. Impact of prolonged sitting on vascular function in young girls. Exp Physiol 2015; 100:1379-87. [PMID: 26370881 DOI: 10.1113/ep085355] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/26/2015] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Children are spending more than 60% of their waking day sedentary. The consequences of excessive sedentary behaviour are not well understood in the child, but there is growing evidence that with increasing sedentary time, cardiovascular risk in childhood also increases. What is the main finding and its importance? Our findings show that a 3 h period of uninterrupted sitting causes a profound (33%) reduction in vascular function in young girls. Importantly, we also demonstrate that breaking up sitting with regular exercise breaks can prevent this. Excessive sedentary behaviour has serious clinical and public health implications; however, the physiological changes that accompany prolonged sitting in the child are not completely understood. Herein, we examined the acute effect a prolonged period of sitting has upon superficial femoral artery function in 7- to 10-year-old girls and the impact of interrupting prolonged sitting with exercise breaks. Superficial femoral artery endothelium-dependent flow-mediated dilatation, total shear rate, anterograde and retrograde shear rates and oscillatory shear index were assessed before and after two experimental conditions: a 3 h uninterrupted period of sitting (SIT) and a 3 h period of sitting interrupted each hour with 10 min of moderate-intensity exercise (EX). A mixed-model analysis of variance was used to compare between-condition and within-condition main effects, controlling for the within-subject nature of the experiment by including random effects for participant. Superficial femoral artery endothelium-dependent flow-mediated dilatation decreased significantly from pre- to post-SIT (mean difference 2.2% flow-mediated dilatation; 95% confidence interval = 0.60-2.94%, P < 0.001). This relative decline of 33% was abolished in the EX intervention. Shear rates were not significantly different within conditions. Our data demonstrate the effectiveness of short but regular exercise breaks in offsetting the detrimental effects of uninterrupted sitting in young girls.
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Affiliation(s)
- Ali M McManus
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Daniel J Green
- School of Sport Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia, Australia.,Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK
| | - Ryan G Simair
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Kurt Smith
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Nia Lewis
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
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Reliability of measurement of endothelial function across multiple institutions and establishment of reference values in Japanese. Atherosclerosis 2015; 242:433-42. [DOI: 10.1016/j.atherosclerosis.2015.08.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 07/28/2015] [Accepted: 08/02/2015] [Indexed: 01/12/2023]
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36
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Atkinson CL, Carter HH, Naylor LH, Dawson EA, Marusic P, Hering D, Schlaich MP, Thijssen DHJ, Green DJ. Opposing effects of shear-mediated dilation and myogenic constriction on artery diameter in response to handgrip exercise in humans. J Appl Physiol (1985) 2015; 119:858-64. [PMID: 26294751 DOI: 10.1152/japplphysiol.01086.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 08/01/2015] [Indexed: 11/22/2022] Open
Abstract
While the impact of changes in blood flow and shear stress on artery function are well documented, the acute effects of increases in arterial pressure are less well described in humans. The aim of this study was to assess the effect of 30 min of elevated blood pressure, in the absence of changes in shear stress or sympathetic nervous system (SNS) activation, on conduit artery diameter. Ten healthy male subjects undertook three sessions of 30 min unilateral handgrip exercise at 5, 10, and 15% of maximal voluntary contractile (MVC) strength. Brachial artery shear rate and blood flow profiles were measured simultaneously during exercise in the active and contralateral resting arms. Bilateral brachial artery diameter was simultaneously assessed before and immediately postexercise. In a second experiment, six subjects repeated the 15% MVC condition while continuous vascular measurements were collected during muscle sympathetic nerve activity (MSNA) assessment using peroneal microneurography. We found that unilateral handgrip exercise at 5, 10, and 15% MVC strength induced stepwise elevations in blood pressure (P < 0.01, Δmean arterial pressure: 7.06 ± 2.44, 8.50 ± 2.80, and 18.35 ± 3.52 mmHg, P < 0.01). Whereas stepwise increases were evident in shear rate in the exercising arm (P < 0.001), no changes were apparent in the nonexercising limb (P = 0.42). Brachial artery diameter increased in the exercising arm (P = 0.02), but significantly decreased in the nonexercising arm (P = 0.03). At 15% MVC, changes in diameter were significantly different between arms (interaction effect: P = 0.01), whereas this level of exertion produced no significant changes in MSNA. We conclude that acute increases in transmural pressure, independent of shear rate and changes in SNS activation, reduce arterial caliber in normotensive humans in vivo. These changes in diameter were mitigated by exercise-induced elevations in shear rate in the active limb.
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Affiliation(s)
- Ceri L Atkinson
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia
| | - Howard H Carter
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia
| | - Louise H Naylor
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia
| | - Ellen A Dawson
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom
| | - Petra Marusic
- School of Medicine and Pharmacology, The University of Western Australia, Crawley, Western Australia; and
| | - Dagmara Hering
- School of Medicine and Pharmacology, The University of Western Australia, Crawley, Western Australia; and
| | - Markus P Schlaich
- School of Medicine and Pharmacology, The University of Western Australia, Crawley, Western Australia; and
| | - Dick H J Thijssen
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom; Department of Physiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Daniel J Green
- School of Sports Science, Exercise and Health, The University of Western Australia, Crawley, Western Australia; Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, United Kingdom;
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Bond B, Gates PE, Jackman SR, Corless LM, Williams CA, Barker AR. Exercise intensity and the protection from postprandial vascular dysfunction in adolescents. Am J Physiol Heart Circ Physiol 2015; 308:H1443-50. [PMID: 25820392 DOI: 10.1152/ajpheart.00074.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/24/2015] [Indexed: 12/26/2022]
Abstract
Acute exercise transiently improves endothelial function and protects the vasculature from the deleterious effects of a high-fat meal (HFM). We sought to identify whether this response is dependent on exercise intensity in adolescents. Twenty adolescents (10 male, 14.3 ± 0.3 yr) completed three 1-day trials: 1) rest (CON); 2) 8 × 1 min cycling at 90% peak power with 75 s recovery [high-intensity interval exercise (HIIE)]; and 3) cycling at 90% of the gas exchange threshold [moderate-intensity exercise (MIE)] 1 h before consuming a HFM (1.50 g/kg fat). Macrovascular and microvascular endothelial function was assessed before and immediately after exercise and 3 h after the HFM by flow-mediated dilation (FMD) and laser Doppler imaging [peak reactive hyperemia (PRH)]. FMD and PRH increased 1 h after HIIE [P < 0.001, effect size (ES) = 1.20 and P = 0.048, ES = 0.56] but were unchanged after MIE. FMD and PRH were attenuated 3 h after the HFM in CON (P < 0.001, ES = 1.78 and P = 0.02, ES = 0.59). FMD remained greater 3 h after the HFM in HIIE compared with MIE (P < 0.001, ES = 1.47) and CON (P < 0.001, ES = 2.54), and in MIE compared with CON (P < 0.001, ES = 1.40). Compared with CON, PRH was greater 3 h after the HFM in HIIE (P = 0.02, ES = 0.71) and MIE (P = 0.02, ES = 0.84), with no differences between HIIE and MIE (P = 0.72, ES = 0.16). Plasma triacylglycerol concentration and total antioxidant status concentration were not different between trials. We conclude that exercise intensity plays an important role in protecting the vasculature from the deleterious effects of a HFM. Performing HIIE may provide superior vascular benefits than MIE in adolescent groups.
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Affiliation(s)
- B Bond
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - P E Gates
- Diabetes and Vascular Medicine, University of Exeter Medical School, Exeter, United Kingdom; and
| | - S R Jackman
- Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - L M Corless
- Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - C A Williams
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - A R Barker
- Children's Health and Exercise Research Centre, Sport and Health Science, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom;
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Impact of handgrip exercise intensity on brachial artery flow-mediated dilation. Eur J Appl Physiol 2015; 115:1705-13. [PMID: 25805181 DOI: 10.1007/s00421-015-3157-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/17/2015] [Indexed: 01/22/2023]
Abstract
PURPOSE Previous studies that have examined the impact of exercise intensity on conduit artery endothelial function have involved large muscle group exercise which induces local and systemic effects. The aim of this study was to examine flow-mediated dilation (FMD) before and after incremental intensities of handgrip exercise (HE), to assess the role of local factors such as blood flow and shear rate on post-exercise brachial artery function. METHODS Eleven healthy men attended the laboratory on three occasions. Subjects undertook 30 min of handgrip exercise at three intensities (5, 10 or 15 % MVC). Brachial artery FMD, shear and blood flow patterns were examined before, immediately after and 60 min post exercise. RESULTS Handgrip exercise increased mean and antegrade shear rate (SR) and blood flow (BF) and reduced retrograde SR and BF (all P < 0.01). Exercise intensity was associated with a dose-dependent increase in both mean and antegrade BF and SR (interaction, P < 0.01). Post-hoc tests revealed that, whilst handgrip exercise did not immediately induce post-exercise changes, FMD was significantly higher 60 min post-exercise following the highest exercise intensity (5.9 ± 2.8-10.4 ± 5.8 %, P = 0.01). CONCLUSIONS Handgrip exercise leads to intensity-and time-dependent changes in conduit artery function, possibly mediated by local increases in shear, with improvement in function evident at 1 h post-exercise when performed at a higher intensity.
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Irace C, Tripolino C, Scavelli F, Messiniti V, Tassone B, Della Valle E, Carallo C, Gnasso A. Blood viscosity but not shear stress associates with delayed flow-mediated dilation. Eur J Appl Physiol 2014; 115:747-53. [PMID: 25428725 DOI: 10.1007/s00421-014-3058-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 11/17/2014] [Indexed: 01/22/2023]
Abstract
PURPOSE Flow-mediated dilation (FMD) is a complex mechanism involving several mediators, and different hemodynamic forces. Temporally distinct FMD patterns can be elicited by ischemic stimulus. Some subjects dilate early after cuff release, while others dilate later or do not dilate at all. Aim of the present research was to verify if hemorheological and hemodynamic factors might influence different FMD pattern. METHODS 148 free-living subjects were studied. FMD was measured at 50 s, 2 min and 3 min. Blood viscosity was measured and shear stress calculated. Shear stress stimulus was quantified as the area under the curve after ischemia (SSAUC) over the first 40-s post-occlusion. RESULTS Based on the timing or absence of arterial dilation, 82 subjects were classified as Early dilators, 37 as Late dilators and 29 as No dilators. Peak FMD was 7.9 ± 4.3 % in Early dilators, and 9.1 ± 5.7 in Late dilators (p = NS). SSAUC was not significantly different among three groups, while blood viscosity was significantly higher in Late FMD subjects. Regression analyses showed the independent predictive role of age and blood viscosity on FMD patterns, and the lack of any association between FMD pattern and the magnitude of SS. CONCLUSIONS The present study demonstrates that age and blood viscosity but not the magnitude of SS explain the different timing of the dilatory response to ischemia.
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Affiliation(s)
- Concetta Irace
- Department of Clinical and Experimental Medicine, Magna Græcia University, University Campus "Salvatore Venuta", Viale Europa, Località Germaneto, 88100, Catanzaro, Italy
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Totosy de Zepetnek JO, Jermey TL, MacDonald MJ. Superficial femoral artery endothelial responses to a short-term altered shear rate intervention in healthy men. PLoS One 2014; 9:e113407. [PMID: 25415320 PMCID: PMC4240593 DOI: 10.1371/journal.pone.0113407] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 10/24/2014] [Indexed: 11/18/2022] Open
Abstract
In animal and in-vitro models, increased oscillatory shear stress characterized by increased retrograde shear-rate (SR) is associated with acutely decreased endothelial cell function. While previous research suggests a possible detrimental role of elevated retrograde SR on endothelial-function in the brachial artery in humans, little research has been conducted examining arteries in the leg. Examinations of altered shear pattern in the superficial femoral artery (SFA) are important, as this vessel is both prone to atherosclerosis and leg exercise is a common form of activity in humans. Seven healthy men participated; bilateral endothelial-function was assessed via flow-mediated-dilation (FMD) before and after 30-minute unilateral inflations of a thigh blood pressure cuff to either 75 mmHg or 100 mmHg on two separate visits. Inflation of the cuff induced increases in maximum anterograde (p<0.05), maximum retrograde (p<0.01), and oscillatory shear index (OSI) (p<0.001) in the cuffed leg at both inflation pressures. At 100 mmHg the increases in SR were larger in the retrograde than the anterograde direction evidenced by a decrease in mean SR (p<0.01). There was an acute decrease in relative FMD in the cuffed leg alone following inflation to both pressures. These results indicate that in the SFA, altered SR profiles incorporating increased retrograde and OSI influence the attenuation in FMD after a 30-minute unilateral thigh-cuff inflation intervention. Novel information highlighting the importance of OSI calculations and assessments of flow profiles add to current body of knowledge regarding the influence of changes in SR patterns on FMD. Findings from the current study may provide additional insight when designing strategies to combat impaired vascular function in the lower extremity where blood vessels are more prone to atherosclerosis in comparison to the upper extremity.
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Affiliation(s)
| | - Tena L. Jermey
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Maureen J. MacDonald
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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Veglia F, Amato M, Giovannardi M, Ravani A, Tedesco CC, Frigerio B, Sansaro D, Tremoli E, Baldassarre D. Potentially spurious correlations between arterial size, flow-mediated dilation, and shear rate. Hypertension 2014; 64:1328-33. [PMID: 25245392 DOI: 10.1161/hypertensionaha.114.03608] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The use of indices formed from the ratio of 2 variables often generates spurious correlations with other variables that are mathematically coupled. In this context, we examined the correlations between percent flow-mediated dilation, baseline diameter, and shear rate. In a sample of 315 participants, with and without substantial vascular risk factors, the observed correlation coefficients between the variables were of a similar magnitude to those reported in the literature. We then applied a Monte Carlo procedure based on random permutations to remove any physical or physiological explanation for these correlations. We found that the median residual correlation coefficients were comparable with those observed in our original sample. When the confounding influence of artery size was adjusted for, the mean difference in percent flow-mediated dilation between high-risk and low-risk samples was halved. These findings indicate that the widely reported correlations between flow-mediated dilation, basal artery diameter, and shear rate have a substantial spurious component. This is because percent flow-mediated dilation and shear rate are mathematically coupled to artery size.
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Affiliation(s)
- Fabrizio Veglia
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.).
| | - Mauro Amato
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Marta Giovannardi
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Alessio Ravani
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Calogero C Tedesco
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Beatrice Frigerio
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Daniela Sansaro
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Elena Tremoli
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
| | - Damiano Baldassarre
- From Centro Cardiologico Monzino IRCCS, Milan, Italy (F.V., M.A., M.G., A.R., C.C.T., B.F., E.T., D.B.); and Dipartimento di Scienze Farmacologiche e Biomolecolari, Università di Milano, Milan, Italy (E.T., D.B.)
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Lennon-Edwards S, Ramick MG, Matthews EL, Brian MS, Farquhar WB, Edwards DG. Salt loading has a more deleterious effect on flow-mediated dilation in salt-resistant men than women. Nutr Metab Cardiovasc Dis 2014; 24:990-995. [PMID: 24989702 PMCID: PMC4195435 DOI: 10.1016/j.numecd.2014.05.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 04/15/2014] [Accepted: 05/05/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIMS Dietary sodium loading has been shown to adversely impact endothelial function independently of blood pressure (BP). However, it is unknown whether dietary sodium loading impacts endothelial function differently in men as compared to women. The aim of this study was to test the hypothesis that endothelial-dependent dilation (EDD) would be lower in men as compared to women in response to a high sodium diet. METHODS AND RESULTS Thirty subjects (14F, 31±2y; 16M, 29±2y) underwent a randomized, crossover, controlled diet study consisting of 7 days of low sodium (LS; 20 mmol/day) and 7 days of high sodium (HS; 300-350 mmol/day). Salt-resistance was determined by a change in 24-hr mean arterial pressure (MAP) ≤ 5 mm Hg between HS and LS as assessed on day 7 of each diet. Blood and 24-hr urine were also collected and EDD was assessed by brachial artery flow-mediated dilation (FMD). By design, MAP was not different between LS and HS conditions and urinary sodium excretion increased on HS diet (P < 0.01). FMD did not differ between men and women on the LS diet (10.2 ± 0.65 vs. 10.7 ± 0.83; P > 0.05) and declined in both men and women on HS (P < 0.001). However, FMD was lower in men as compared to women on HS (5.7 ± 0.5 vs. 8.6 ± 0.86; P < 0.01). CONCLUSIONS HS reduced FMD in both men and women. In response to an HS diet, FMD was lower in men compared to women suggesting a greater sensitivity of the vasculature to high sodium in men.
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Affiliation(s)
- S Lennon-Edwards
- Department of Behavioral Health and Nutrition, University of Delaware, Newark, DE, USA; Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA.
| | - M G Ramick
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - E L Matthews
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - M S Brian
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - W B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA; Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - D G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA; Department of Biological Sciences, University of Delaware, Newark, DE, USA
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Fox BM, Brantley L, White C, Seigler N, Harris RA. Association beween resting heart rate, shear and flow-mediated dilation in healthy adults. Exp Physiol 2014; 99:1439-48. [PMID: 25037565 DOI: 10.1113/expphysiol.2014.080960] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Preclinical data have demonstrated that heart rate (HR) can directly impact vascular endothelial function, in part, through a shear-stress mechanism. This study sought to explore, in humans, the associations between resting heart rate and both shear and endothelial function assessed by flow-mediated dilation (FMD). The brachial artery FMD test was performed in 31 apparently healthy volunteers. Basal (B) and hyperaemic (H) shear were quantified in the following two ways using data from the FMD test: the traditional cumulative shear area under the curve up to peak dilation (Shearcum) method; and our novel method of shear summation (Shearsum), which accounts for HR by summing each individual cardiac cycle shear up to peak dilation. Data were grouped by tertiles based on resting HR as follows: low (LHR = 43-56 beats min(-1); n = 10); middle (MHR = 58-68 beats min(-1); n = 11); and high (HHR = 69-77 beats min(-1); n = 10). Within the LHR group, both B-Shearcum and H-Shearcum were significantly higher (P < 0.001) than B-Shearsum and H-Shearsum, respectively, whereas in the HHR group B-Shearcum and H-Shearcum were significantly lower (P < 0.001) than B-Shearsum and H-Shearsum, respectively. The FMD in the LHR group (8.8 ± 0.8%) was significantly greater than that in both the MHR group (5.5 ± 0.8%; P = 0.009) and the HHR group (5.9 ± 0.8%; P = 0.024). These findings demonstrate the existence of a relationship between heart rate and both shear and endothelial function in humans. Moreover, these findings have implications for considering heart rate as an important physiological variable when quantifying shear and performing the FMD test.
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Affiliation(s)
- Brandon M Fox
- Institute of Preventive and Public Health, Georgia Prevention Center, Georgia Regents University, Augusta, GA, UK
| | - Lucy Brantley
- Institute of Preventive and Public Health, Georgia Prevention Center, Georgia Regents University, Augusta, GA, UK
| | - Claire White
- Institute of Preventive and Public Health, Georgia Prevention Center, Georgia Regents University, Augusta, GA, UK
| | - Nichole Seigler
- Institute of Preventive and Public Health, Georgia Prevention Center, Georgia Regents University, Augusta, GA, UK
| | - Ryan A Harris
- Institute of Preventive and Public Health, Georgia Prevention Center, Georgia Regents University, Augusta, GA, UK Sport and Exercise Science Research Institute, University of Ulster, Jordanstown, County Antrim, UK
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Bruno RM, Cogo A, Ghiadoni L, Duo E, Pomidori L, Sharma R, Thapa GB, Basnyat B, Bartesaghi M, Picano E, Sicari R, Taddei S, Pratali L. Cardiovascular function in healthy Himalayan high-altitude dwellers. Atherosclerosis 2014; 236:47-53. [PMID: 25014034 DOI: 10.1016/j.atherosclerosis.2014.06.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 06/11/2014] [Accepted: 06/19/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Residents of the Himalayan valleys uniquely adapted to their hypoxic environment in terms of pulmonary vasculature, but their systemic vascular function is still largely unexplored. The aim of the study was to investigate vascular function and structure in rural Sherpa population, permanently living at high altitude in Nepal (HA), in comparison with control Caucasian subjects (C) living at sea level. METHODS AND RESULTS 95 HA and 64 C were enrolled. Cardiac ultrasound, flow-mediated dilation (FMD) of the brachial artery, carotid geometry and stiffness, and aortic pulse wave velocity (PWV) were performed. The same protocol was repeated in 11 HA with reduced FMD, after 1-h 100% O2 administration. HA presented lower FMD (5.18 ± 3.10 vs. 6.44 ± 2.91%, p = 0.02) and hyperemic velocity than C (0.61 ± 0.24 vs. 0.75 ± 0.28 m/s, p = 0.008), while systolic pulmonary pressure was higher (29.4 ± 5.5 vs. 23.6 ± 4.8 mmHg, p < 0.0001). In multiple regression analysis performed in HA, hyperemic velocity remained an independent predictor of FMD, after adjustment for baseline brachial artery diameter, room temperature and pulse pressure, explaining 8.7% of its variance. On the contrary, in C brachial artery diameter remained the only independent predictor of FMD, after adjustment for confounders. HA presented also lower carotid IMT than C (0.509 ± 0.121 vs. 0.576 ± 0.122 mm, p < 0.0001), higher diameter (6.98 ± 1.07 vs. 6.81 ± 0.85 mm, p = 0.004 adjusted for body surface area) and circumferential wall stress (67.6 ± 13.1 vs. 56.4 ± 16.0 kPa, p < 0.0001), while PWV was similar. O2 administration did not modify vascular variables. CONCLUSIONS HA exhibit reduced NO-mediated dilation in the brachial artery, which is associated to reduced hyperemic response, indicating microcirculatory dysfunction. A peculiar carotid phenotype, characterized by reduced IMT and enlarged diameter, was also found.
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Affiliation(s)
- R M Bruno
- Institute of Clinical Physiology - CNR, Pisa, Italy; Department of Clinical and Experimental Medicine, University of Pisa, Italy.
| | - A Cogo
- Biomedical Sport Studies Center, University of Ferrara, Italy
| | - L Ghiadoni
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - E Duo
- Biomedical Sport Studies Center, University of Ferrara, Italy
| | - L Pomidori
- Biomedical Sport Studies Center, University of Ferrara, Italy
| | - R Sharma
- Nepal International Clinic, Kathmandu, Nepal
| | - G B Thapa
- Nepal International Clinic, Kathmandu, Nepal
| | - B Basnyat
- Nepal International Clinic, Kathmandu, Nepal
| | - M Bartesaghi
- Department of Experimental Medicine, Laboratory of Clinical Physiology and Sport Medicine, University of Milano-Bicocca, Italy
| | - E Picano
- Institute of Clinical Physiology - CNR, Pisa, Italy
| | - R Sicari
- Institute of Clinical Physiology - CNR, Pisa, Italy
| | - S Taddei
- Department of Clinical and Experimental Medicine, University of Pisa, Italy
| | - L Pratali
- Institute of Clinical Physiology - CNR, Pisa, Italy
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Irace C, Padilla J, Carallo C, Scavelli F, Gnasso A. Delayed vasodilation is associated with cardiovascular risk. Eur J Clin Invest 2014; 44:549-56. [PMID: 24738967 DOI: 10.1111/eci.12268] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 04/11/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Flow-mediated dilation (FMD) of the brachial artery is widely used to assess cardiovascular risk. In recent years, much attention has been paid to the kinetics of vasodilation in an attempt to better characterize the endothelial function. Here, we investigated whether FMD magnitude and/or latency are most related to individual cardiovascular risk. MATERIALS AND METHODS Four hundred subjects were recruited. Individual risk prediction was estimated by Framingham cardiovascular risk score and CUORE project calculator. Subjects were divided into Early dilators (peak FMD at 50 s), Late dilators (peak FMD over 50 s) and No dilators. RESULTS Cardiovascular risk was highest in No dilators and significantly higher in Late than Early dilators despite comparable peak FMD. When divided according to peak FMD quintiles, Early and Late dilators showed decreased cardiovascular risk with increasing magnitude of vasodilation. However, subjects in the first three quintiles of Late dilators had a markedly higher risk score despite a peak vasodilation similar to that of Early dilators. CONCLUSION These results suggest that the magnitude of the FMD and its latency are both important for identifying patients at risk of cardiovascular disease. Subjects with a delayed though significant vasodilation associated with a blunted early response exhibit the highest cardiovascular risk.
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Affiliation(s)
- Concetta Irace
- Department of Clinical and Experimental Medicine, University Magna Graecia, Catanzaro, Italy
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Hu YJ, Wei AN, Chook P, Yin Y, Cheng W, Wu MJ, Celermajer DS, Woo KS. Impact of non-cardiovascular surgery on reactive hyperaemia and arterial endothelial function. Clin Exp Pharmacol Physiol 2014; 40:466-72. [PMID: 23662794 DOI: 10.1111/1440-1681.12111] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Revised: 05/02/2013] [Accepted: 05/07/2013] [Indexed: 11/28/2022]
Abstract
Vascular reactivity is a surrogate marker for atherosclerosis and is predictive of cardiovascular outcome. Non-cardiovascular surgery is associated with perioperative cardiovascular complications in high-risk patients. To evaluate the impact of non-cardiovascular surgery on reactive hyperaemia and arterial endothelial function and to investigate the relationships between endothelial dysfunction and invasive (laparotomy) or minimally invasive (laparoscopic) surgery, we prospectively evaluated 106 patients undergoing abdominal surgery under general anaesthesia (71 laparotomy, 35 laparoscopy). Measurements of blood pressure, heart rate and pain (on a visual analogue scale (VAS)) were undertaken. Brachial endothelium-dependent flow-mediated dilation (FMD), endothelium-independent dilation, nitroglycerin (NTG)-induced dilation and reactive hyperaemia were measured with high-resolution B-mode ultrasound on preoperative Day 1 (baseline), as well as 2 h and 1 and 7 days postoperatively. Blood pressure and heart rate were significantly higher 2 h postoperatively. Pain, as measured on the VAS, was higher (P < 0.01) and reactive hyperaemia and FMD were significantly lower (P < 0.001) at 2 h and 1 day postoperatively compared with values at baseline and on postoperative Day 7. By postoperative Day 7, FMD had recovered to baseline levels. Patients undergoing laparoscopic surgery had less FMD reduction on Days 1 and 7 (7.5 ± 1.5% and 7.9 ± 1.5%, respectively) compared with those undergoing laparotomy (6.4 ± 1.6% (P = 0.001) and 7.0 ± 1.6% (P = 0.006), respectively), consistent with potential cardiovascular benefit. Responses to NTG were stable throughout. Backward multivariate linear regression analysis indicated that FMD was independently related to age and VAS (model R = 0.486; F = 6.4; P < 0.001). Reactive hyperaemia and arterial endothelial function are significantly reduced in the early postoperative period, particularly after laparotomy compared with laparoscopy, which may be related to postoperative cardiovascular events.
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Affiliation(s)
- Yan Jun Hu
- The Second Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing, China
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Poitras VJ, Slattery DJ, Levac BM, Fergus S, Gurd BJ, Pyke KE. The combined influence of fat consumption and repeated mental stress on brachial artery flow-mediated dilatation: a preliminary study. Exp Physiol 2014; 99:715-28. [DOI: 10.1113/expphysiol.2013.077131] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Veronica J. Poitras
- School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| | - David J. Slattery
- School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| | - Brendan M. Levac
- School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| | - Stevenson Fergus
- School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| | - Brendon J. Gurd
- School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
| | - Kyra E. Pyke
- School of Kinesiology and Health Studies; Queen's University; Kingston Ontario Canada
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Swift DL, Weltman JY, Patrie JT, Saliba SA, Gaesser GA, Barrett EJ, Weltman A. Predictors of improvement in endothelial function after exercise training in a diverse sample of postmenopausal women. J Womens Health (Larchmt) 2013; 23:260-6. [PMID: 24299160 DOI: 10.1089/jwh.2013.4420] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Endothelial dysfunction measured via flow-mediated dilation (FMD) is associated with greater risk of future hypertension and cardiovascular events in postmenopausal women. Aerobic exercise training has been shown to improve endothelial function in Caucasian populations, but has not been evaluated specifically in African Americans. This has clinical importance due to the increased prevalence of cardiovascular disease in African Americans. METHODS In the present pilot study, 8 African American (age: 55.8±1.7 years, peak oxygen uptake [VO2 peak]: 21.0±3.9 mL/kg/minute, body mass index [BMI]: 30.1± 6.3 kg/m(2)) and 16 Caucasian (age: 57.2±5.9 years, VO2 peak: 21.8±3.7 mL/kg/minute, BMI: 29.3±5.2 kg/m(2)) sedentary postmenopausal women underwent brachial artery FMD measurements before and after 12 weeks of aerobic exercise training. FMD was quantified by comparing B-mode ultrasound images of the brachial artery at rest and following reactive hyperemia after 5 minutes of forearm occlusion. Participants performed aerobic exercise training 4 days per week for 12 weeks. RESULTS Despite improvements in fitness in both groups, aerobic exercise training did not significantly improve FMD in African American (5.8% to 5.7%, p=0.950) or Caucasian postmenopausal women (5.7% to 6.6%, p=0.267). In women with the greatest impairment in endothelial function at baseline (FMD<4.5%), a significant improvement in FMD was observed, independent of race, following exercise training (2.2% to 6.2%, p=0.007). CONCLUSION The benefits of aerobic exercise training on endothelial function in postmenopausal women are most pronounced in women with endothelial dysfunction prior to training and do not appear to be affected by race.
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Affiliation(s)
- Damon L Swift
- 1 Department of Human Services, University of Virginia , Charlottesville, Virginia
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Curran-Everett D. Explorations in statistics: the analysis of ratios and normalized data. ADVANCES IN PHYSIOLOGY EDUCATION 2013; 37:213-9. [PMID: 24022766 DOI: 10.1152/advan.00053.2013] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This ninth installment of Explorations in Statistics explores the analysis of ratios and normalized-or standardized-data. As researchers, we compute a ratio-a numerator divided by a denominator-to compute a proportion for some biological response or to derive some standardized variable. In each situation, we want to control for differences in the denominator when the thing we really care about is the numerator. But there is peril lurking in a ratio: only if the relationship between numerator and denominator is a straight line through the origin will the ratio be meaningful. If not, the ratio will misrepresent the true relationship between numerator and denominator. In contrast, regression techniques-these include analysis of covariance-are versatile: they can accommodate an analysis of the relationship between numerator and denominator when a ratio is useless.
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Affiliation(s)
- Douglas Curran-Everett
- Division of Biostatistics and Bioinformatics, National Jewish Health, Denver, Colorado; and Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado, Denver, Colorado
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Schreuder THA, Eijsvogels TMH, Greyling A, Draijer R, Hopman MTE, Thijssen DHJ. Effect of black tea consumption on brachial artery flow-mediated dilation and ischaemia-reperfusion in humans. Appl Physiol Nutr Metab 2013; 39:145-51. [PMID: 24476469 DOI: 10.1139/apnm-2012-0450] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tea consumption is associated with reduced cardiovascular risk. Previous studies found that tea flavonoids work through direct effects on the vasculature, leading to dose-dependent improvements in endothelial function. Cardioprotective effects of regular tea consumption may relate to the prevention of endothelial ischaemia-reperfusion (IR) injury. Therefore, we examined the effect of black tea consumption on endothelial function and the ability of tea to prevent IR injury. In a randomized, crossover study, 20 healthy subjects underwent 7 days of tea consumption (3 cups per day) or abstinence from tea. We examined brachial artery (BA) endothelial function via flow-mediated dilation (FMD), using high resolution echo-Doppler, before and 90 min after tea or hot water consumption. Subsequently, we followed a 20-min ischaemia and 20-min reperfusion protocol of the BA after which we measured FMD to examine the potential of tea consumption to protect against IR injury. Tea consumption resulted in an immediate increase in FMD% (pre-consumption: 5.8 ± 2.5; post-consumption: 7.2 ± 3.2; p < 0.01), whilst no such change occurred after ingestion of hot water. The IR protocol resulted in a significant decrease in FMD (p < 0.005), which was also present after tea consumption (p < 0.001). This decline was accompanied by an increase in the post-IR baseline diameter. In conclusion, these data indicate that tea ingestion improves BA FMD. However, the impact of the IR protocol on FMD was not influenced by tea consumption. Therefore, the cardioprotective association of tea ingestion relates to a direct effect of tea on the endothelium in humans in vivo.
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Affiliation(s)
- Tim H A Schreuder
- a Department of Physiology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, the Netherlands
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