Association between exercise hemodynamics and changes in local vascular function following acute exercise

2011 ◽  
Vol 36 (1) ◽  
pp. 137-144 ◽  
Author(s):  
Joaquin U. Gonzales ◽  
Benjamin C. Thompson ◽  
John R. Thistlethwaite ◽  
Barry W. Scheuermann
Keyword(s):  
Blood Pressure ◽  
Shear Rate ◽  
Brachial Artery ◽  
Vascular Function ◽  
Acute Exercise ◽  
Contractile Activity ◽  
Healthy Individuals ◽  
Physical Stimuli ◽  
Exercise Hemodynamics ◽  
Artery Flow

Skeletal muscle contractions are associated with physical stimuli that act upon muscle vasculature, including increased shear stress and blood pressure. It is unclear if acute dynamic exercise alters local vascular function. The purpose of this study was to examine the role of exercise hemodynamics on the effects of acute exercise on vascular function, as evaluated by brachial artery flow-mediated dilation (FMD). Healthy individuals (n = 14; age, 18–34 years) performed 30 min of handgrip exercise at fast and slow contractions. Blood pressure during exercise was measured using a Vasotrac system (Medwave Inc.), while shear rate during exercise and FMD at rest and after 30 min of recovery from exercise were measured in the brachial artery of the active arm using Doppler ultrasound. Estimated contractile work was correlated with blood pressure (r = 0.61, p < 0.01) and retrograde shear rate (r = –0.78, p < 0.01). As a result, blood pressure was higher (p < 0.05) and oscillatory shear index was lower (p < 0.05) during slow as compared with fast contractions. On average, FMD was unchanged following fast contractions (5.4 ± 3.4%dilation to 6.1 ± 3.8%dilation; p = 0.19), but significantly reduced following slow contractions (6.9 ± 4.2%dilation to 3.6 ± 2.5%dilation; p = 0.01). Within slow contractions, subgroup analysis revealed blood pressure to associate with the change in FMD; such that individuals with mean blood pressure >100 mm Hg (range, 102–139 mm Hg) during exercise had larger decreases in FMD than individuals with lower exercise blood pressure. These results indicate that impaired local vascular function following acute exercise with high contractile activity is associated with blood pressure stimuli in healthy individuals

scholarly journals Reference Intervals for Brachial Artery Flow-Mediated Dilation and the Relation With Cardiovascular Risk Factors

Hypertension ◽  
2021 ◽  
Author(s):  
Sophie M. Holder ◽  
Rosa Maria Bruno ◽  
Daria A. Shkredova ◽  
Ellen A. Dawson ◽  
Helen Jones ◽  
...  
Keyword(s):  
Risk Factors ◽  
Blood Pressure ◽  
Brachial Artery ◽  
Reference Intervals ◽  
Flow Mediated Dilation ◽  
Healthy Individuals ◽  
Cvd Risk Factors ◽  
Cvd Risk ◽  
Artery Flow ◽  
Age And Sex

Endothelial function, assessed using brachial artery flow-mediated dilation (FMD), predicts future cardiovascular disease (CVD) risk. This study established age- and sex-specific reference intervals for brachial artery FMD in healthy individuals and examined the relation with CVD risk factors. In a retrospective study design, we pooled brachial artery FMD (acquired according to expert-consensus guidelines for FMD protocol and analysis) and participant characteristics/medical history from 5362 individuals (4–84 years; 2076 females). Healthy individuals (n=1403 [582 females]) were used to generate age-/sex-specific percentile curves. Subsequently, we included individuals with CVD risk factors, without overt disease (unmedicated n=3167 [1247 females] and medicated n=792 [247 females]). Multiple linear regression tested the relation of CVD risk factors (body mass index, blood pressure, cholesterol, diabetes, dyslipidemia, and smoking) with FMD. Healthy males showed a negative, curvilinear relation between FMD and age, while females revealed a negative linear relation that started higher but declined at a faster rate than males. Age- and sex-specific differences in FMD relate, at least partly, to baseline artery diameter. FMD was related to CVD risk factors in unmedicated (eg, systolic/diastolic blood pressure) and medicated individuals (eg, diabetes/dyslipidemia). Sex mediated some of these effects ( P <0.05), with normalization of FMD in medicated men, but not women with dyslipidemia. In conclusion, sex alters the age-related decline in FMD, which may partly be explained through differences in baseline diameter. Sex also alters the influence of some CVD risk factors and medication on FMD. This work improves interpretation and future use of the FMD technique.

Abstract 16926: The Effects of a Mitochondrial Targeted Ubiquinone (MitoQ) on Vascular Function in Chronic Kidney Disease

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Danielle L Kirkman ◽  
Ninette Shenouda ◽  
Joseph M Stock ◽  
Bryce J Muth ◽  
Nicholas Chouramanis ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Brachial Artery ◽  
Vascular Function ◽  
Vascular Dysfunction ◽  
Aortic Pressure ◽  
Double Blind ◽  
Reflected Waves ◽  
Arterial Hemodynamics ◽  
Artery Flow

Introduction: Aberrant vascular function contributes to the substantially high cardiovascular burden of chronic kidney disease (CKD). Mitochondrial derived oxidative stress is a potential therapeutic target to ameliorate CKD related vascular dysfunction. Hypothesis: We hypothesized that a mitochondrial targeted antioxidant (MitoQ) would improve vascular function in Stage 3-5 CKD patients without overt cardiovascular disease. Methods: In this controlled, double-blind trial, 18 CKD patients (Mean±SEM: Age, 62±3 years; eGFR, 45±3 ml•min•1.73 2 ) were randomized to receive an oral dose of MitoQ (20mg/day; MTQ) or a Placebo (PLB) for 4 weeks. Outcome measures were assessed at week 0 and week 4. Aortic pressure waves were synthesized from brachial artery waveforms acquired by oscillometry and the use of a generalized transfer function. The central pressure waveform was separated into forward and reflected waves using a triangular flow waveform. Conduit artery vascular function was assessed via brachial artery flow mediated dilation (FMD). Results: MitoQ was well tolerated and patient compliance was high (MTQ, 99.6±0.4%; PLB, 97.8±2.2%). Independent of peripheral (Baseline vs. Follow Up: MTQ, 140±6 vs. 137±6 mmHg; PLB, 136±4 vs. 134±6 mmHg; interaction p=0.7) and central (MTQ, 128±5 vs. 123±6 mmHg; PLB, 124±3 vs. 123±5 mmHg; interaction p=0.8) systolic blood pressures, MitoQ maintained forward wave amplitudes (MTQ, 31±3 vs. 29±1 mmHg; PLB, 29±3 vs. 36±3 mmHg; interaction p=0.05) and tended to reduce reflected wave amplitudes (MTQ, 18±2 vs. 16±1 mmHg; PLB, 19±2 vs. 21±2 mmHg; interaction p=0.04). MitoQ administration favored improvements in FMD (MTQ, 2.4±0.3 vs. 4.0±0.9%; PLB, 4.2±1.0 vs. 2.5±1.0%; interaction p=0.04). Conclusions: These results suggest that targeting mitochondrial derived reactive oxygen species holds promise as a potential therapeutic strategy to improve CKD related vascular dysfunction. Whether MitoQ related improvements in arterial hemodynamics are a result of augmented cardiac function or a reduction in vascular resistance warrants future investigation in larger studies.

Does Brachial Artery Flow Mediated Vasodilation Reflect Systemic Vascular Function?

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S194
Author(s):  
Steven K. Nishiyama ◽  
David Walter Wray ◽  
Russell S. Richardson
Keyword(s):  
Brachial Artery ◽  
Vascular Function ◽  
Artery Flow ◽  
Flow Mediated Vasodilation

scholarly journals Brachial Artery Flow-mediated Dilation Following Exercise with Augmented Oscillatory and Retrograde Shear Rate

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Blair D Johnson ◽  
Kieren J Mather ◽  
Sean C Newcomer ◽  
Timothy D Mickleborough ◽  
Janet P Wallace
Keyword(s):  
Shear Rate ◽  
Brachial Artery ◽  
Flow Mediated Dilation ◽  
Artery Flow ◽  
Retrograde Shear

Acute Effects of Interrupting Prolonged Sitting on Vascular Function in Type 2 Diabetes

2020 ◽  
Author(s):  
Frances C. Taylor ◽  
David W. Dunstan ◽  
Ashleigh R Homer ◽  
Paddy C. Dempsey ◽  
Bronwyn A Kingwell ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Shear Rate ◽  
Femoral Artery ◽  
Vascular Function ◽  
Acute Effects ◽  
Obese Adults ◽  
Endothelin 1 ◽  
Prolonged Sitting ◽  
Artery Flow

In healthy and overweight/obese adults, interrupting prolonged sitting with activity bouts mitigates impairment in vascular function. However, it is unknown whether these benefits extend to those with type 2 diabetes (T2D); nor, whether an optimal frequency of activity interruptions exist. We examined the acute effects on vascular function in T2D of interrupting prolonged sitting with simple resistance activities (SRA) at different frequencies. In a randomized crossover trial, 24 adults with T2D (35-70 years) completed three 7-hour conditions: 1) uninterrupted sitting (SIT); 2) sitting with 3 minute bouts of SRA every 30 min (SRA3); and, 3) sitting with 6 minute bouts of SRA every 60 min (SRA6). Femoral artery flow-mediated dilation (FMD), resting shear rate, blood flow and endothelin-1 were measured at 0h, 1h, 3.5h, 4.5h, and 6.5-7h. Mean femoral artery FMD over 7 hours was significantly higher in SRA3 (4.1 ± 0.3%) compared to SIT (3.7 ± 0.3%, p = 0.04), but not in SRA6. Mean resting femoral shear rate over 7 hours was increased significantly for SRA3 (45.3±4.1/s, p<0.001) and SRA6 (46.2±4.1/s, p<0.001) relative to SIT (33.1±4.1/s). Endothelin-1 concentrations were not statistically different between conditions. Interrupting sitting with activity breaks every 30 minutes, but not 60 minutes, significantly increased mean femoral artery FMD over 7 hours, relative to SIT. Our findings suggest that more-frequent and shorter breaks may be more beneficial than longer, less-frequent breaks for vascular health in those with T2D.

scholarly journals In-exercise vascular shear rate during acute continuous and interval exercise: impact on endothelial function and miR-21

2019 ◽  
Vol 127 (6) ◽  
pp. 1754-1762
Author(s):  
Gemma Kate Lyall ◽  
Matthew John Davies ◽  
Carrie Ferguson ◽  
Karen E. Porter ◽  
Karen M. Birch
Keyword(s):  
Shear Rate ◽  
Endothelial Function ◽  
Brachial Artery ◽  
Acute Exercise ◽  
Cell Phenotype ◽  
Circulating Microrna ◽  
Specific Exercise ◽  
Exercise Protocol ◽  
Interval Exercise ◽  
Exercise Induced

Endothelial cell phenotype and endothelial function are regulated by hemodynamic forces, particularly wall shear stress (WSS). During a single bout of exercise, the specific exercise protocol can affect in-exercise WSS patterns and, consequently, endothelial function. MicroRNAs might provide a biomarker of in-exercise WSS pattern to indicate whether a specific exercise bout will have a positive effect on endothelial function. We evaluated the effect of acute interval (IT) and continuous (CON) in-exercise WSS patterns upon postexercise endothelial function and circulating microRNA (miR)-21 expression. Methods and results: 13 participants performed CON and 3 different IT exercise protocols matched for duration and intensity on separate days. Oxygen uptake, heart rate, and brachial artery blood flow were recorded throughout the exercise. Brachial artery flow-mediated dilation (FMD) was performed pre-exercise and 15 min postexercise. Plasma samples were acquired pre-exercise and 6 h postexercise to determine miR-21 expression. In-exercise shear rate (SR) patterns (a surrogate of WSS) differed according to the CON or IT work-rate profile. In-exercise anterograde SR was greater in CON than IT exercise ( P < 0.05), but retrograde SR was equivalent between exercise protocols ( P > 0.05). Oscillatory shear index was higher during IT versus CON exercise ( P < 0.05). Postexercise FMD increased (pre: 7.08% ± 2.95%, post: 10.54% ± 4.24%, P < 0.05), whereas miR-21 expression was unchanged (pre: 12.0% ± 20.7% cel-miR-39, post: 11.1 ± 19.3% cel-miR-39, P > 0.05) with no effect of exercise protocol ( P > 0.05). Conclusions: CON and IT exercise induced different SR patterns but equivalent improvements in acute endothelial function. The absence of change in miR-21 expression suggests that miR-21 is not a suitable biomarker of exercise-induced SR. NEW & NOTEWORTHY Interval exercise has the potential to negatively impact vascular adaptations because of repeated oscillations in vascular shear. To our knowledge, we are the first to continuously assess exercise-induced shear throughout different acute exercise protocols and examine its relationship with acute endothelial function and a circulating biomarker of shear (miR-21). These experiments provide clear data indicating enhancement of the acute vascular response from differing interval exercise protocols, with the study also providing detailed vascular and shear responses for future reference.

Low flow-mediated constriction occurs in the radial but not the brachial artery in healthy pregnant and nonpregnant women

2010 ◽  
Vol 108 (5) ◽  
pp. 1097-1105 ◽  
Author(s):  
Tracey L. Weissgerber ◽  
Gregory A. L. Davies ◽  
Michael E. Tschakovsky
Keyword(s):  
Shear Rate ◽  
Pregnant Women ◽  
Radial Artery ◽  
Brachial Artery ◽  
Vascular Function ◽  
Low Flow ◽  
Flow Mediated Dilation ◽  
Brachial Artery Diameter ◽  
Function Test ◽  
Positive Correlations

Radial artery diameter decreases when a wrist cuff is inflated to stop blood flow to distal tissue. This phenomenon, referred to as low flow-mediated vasoconstriction (L-FMC), was proposed as a vascular function test. Recommendations that L-FMC be measured concurrently with flow-mediated dilation (FMD) were based on radial artery data. However, cardiovascular disease prediction studies traditionally measure brachial artery FMD. Therefore, studies should determine whether L-FMC occurs in the brachial artery. The hypothesis that reduced shear causes L-FMC has not been tested. Brachial and radial artery L-FMC and FMD were assessed in active nonpregnant ( n = 17), inactive nonpregnant ( n = 10), active pregnant ( n = 15, 34.1 ± 1.2 wk gestation), and inactive pregnant ( n = 8, 34.2 ± 2.2 wk gestation) women. Radial artery diameter decreased significantly during occlusion in all groups (nonpregnant, −4.4 ± 4.2%; pregnant, −6.4 ± 3.2%). Brachial artery diameter did not change in active and inactive nonpregnant, and inactive pregnant women; however, the small decrease in active pregnant women was significant. Occlusion decreased shear rate in both arteries, yet L-FMC only occurred in the radial artery. Radial artery L-FMC was not correlated with the reduction in shear rate. L-FMC occurs in the radial but not the brachial artery and is not related to changes in shear rate. Positive correlations between L-FMC (negative values) and FMD (positive values) suggest that radial artery FMD may be reduced among women who experience greater L-FMC. Studies should clarify the underlying stimulus and mechanisms regulating L-FMC, and test the hypothesis that endothelial dysfunction is manifested as enhanced brachial artery L-FMC, but attenuated radial artery L-FMC.

scholarly journals Contribution of nitric oxide to brachial artery vasodilation during progressive handgrip exercise in the elderly

2013 ◽  
Vol 305 (8) ◽  
pp. R893-R899 ◽  
Author(s):  
Joel D. Trinity ◽  
D. Walter Wray ◽  
Melissa A. H. Witman ◽  
Gwenael Layec ◽  
Zachary Barrett-O'Keefe ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Shear Rate ◽  
Brachial Artery ◽  
Vascular Function ◽  
The Elderly ◽  
Flow Mediated Dilation ◽  
Handgrip Exercise ◽  
Modest Contribution ◽  
Older Subjects ◽  
The Relationship

The reduction in nitric oxide (NO)-mediated vascular function with age has largely been determined by flow-mediated dilation (FMD). However, in light of recent uncertainty surrounding the NO dependency of FMD and the recognition that brachial artery (BA) vasodilation during handgrip exercise is predominantly NO-mediated in the young, we sought to determine the contribution of NO to BA vasodilation in the elderly using the handgrip paradigm. BA vasodilation during progressive dynamic (1 Hz) handgrip exercise performed at 3, 6, 9, and 12 kg was assessed with and without NO synthase (NOS) inhibition [intra-arterial NG-monomethyl-l-arginine (l-NMMA)] in seven healthy older subjects (69 ± 2 yr). Handgrip exercise in the control condition evoked significant BA vasodilation at 6 (4.7 ± 1.4%), 9 (6.5 ± 2.2%), and 12 kg (9.5 ± 2.7%). NOS inhibition attenuated BA vasodilation, as the first measurable increase in BA diameter did not occur until 9 kg (4.0 ± 1.8%), and the change in BA diameter at 12 kg was reduced by ∼30% (5.1 ± 2.2%), with unaltered shear rate (Control: 407 ± 57, l-NMMA: 427 ± 67 s−1). Although shifted downward, the slope of the relationship between BA diameter and shear rate during handgrip exercise was unchanged (Control: 0.0013 ± 0.0004, l-NMMA: 0.0011 ± 0.007, P = 0.6) as a consequence of NOS inhibition. Thus, progressive handgrip exercise in the elderly evokes a robust BA vasodilation, the magnitude of which was only minimally attenuated following NOS inhibition. This modest contribution of NO to BA vasodilation in the elderly supports the use of the handgrip exercise paradigm to assess NO-dependent vasodilation across the life span.

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