Pilot Study: The Effect of Acute 5-Day Creatine Supplementation on Macrovascular Endothelial Function in Older Adults

Abstract Objectives Cardiovascular disease (CVD) remains the leading cause of mortality in the United States, and aging is a primary risk factor for CVD events. Dietary creatine supplementation has been used to alleviate age-related health deteriorations, and has been shown to reduce sarcopenia, improve cognition and decrease reactive oxygen species in older adults. There is scarce information, however, regarding the use of creatine to improve vascular function. Therefore, the primary aim of this pilot study was to determine the effect of creatine on vascular function in older adults. Methods Four older adults (66 ± 8.3 years) participated in this pilot study, with four young adults (27 ± 2.9 years) serving as a comparator. Participants reported for their baseline visit, and completed basic anthropometrics and resting hemodynamic testing. Brachial artery flow mediated dilation (FMD) was used to assess macrovascular endothelial function following 5-minutes of occlusion. Resting and peak brachial artery diameters were assessed using edge detection software, and FMD % change (FMD%) was determined utilizing the following equation: [(peak diameter – baseline diameter)/baseline diameter] * 100. Participants were then given creatine monohydrate to consume over the following 5 days (4 × 5 g/day), before returning to repeat all assessments. A two-way ANOVA statistical analysis was performed using SPSS software, and significance was accepted at P ≤ 0.05. Results No statistically significant changes were seen in FMD%. However, mean delta (Δ) change for groups did show a greater improvement in FMD% in old vs. young (Δ2.44 ± 1.78% vs. −.82 ± 3.09%) and estimated marginal means of FMD showed a positive change in FMD% in older adults but not in younger. Furthermore, 100% of older adults showed improvement following creatine, whereas only 50% of young adults showed (minimal) improvement. Conclusions Although there were no significant changes identified, this may be due to the small sample size not being sufficient to detect an interaction effect. The improvements seen for each older adult could still be considered physiologically significant for vascular health, and future study of additional participants may result in significant benefits and expand the use of creatine to improve vascular health. Funding Sources No grants or Funding Sources were used for this pilot study.

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Endothelial Function In Tanzanian Children With Sickle Cell Disease: Baseline Results From The Vascular Function Intervention Trial (VFIT)

Blood ◽

10.1182/blood.v122.21.984.984 ◽

2013 ◽

Vol 122 (21) ◽

pp. 984-984

Author(s):

Sharon E. Cox ◽

Julie Makani ◽

Elizabeth Ellins ◽

Gurishaeli Walter ◽

Selemani Mtunguja ◽

...

Keyword(s):

Nitric Oxide ◽

Blood Pressure ◽

Endothelial Function ◽

Sickle Cell ◽

Brachial Artery ◽

Vascular Function ◽

Full Blood Count ◽

Intervention Trial ◽

Brachial Artery Diameter ◽

Baseline Diameter

Abstract Introduction Endothelial function is impaired in adults with sickle cell anaemia (SCA), but limited data exists in children. Endothelial damage occurs from chronic inflammation, oxidant damage, immune cell activation and ischemia-reperfusion injury. In addition, availability of nitric oxide (NO) as the major vasodilator may be reduced as a result of scavenging by plasma haemoglobin and reduced arginine substrate for endothelial nitric oxide synthase. Methods Tanzanian children (N=119) with SCA (HbSS) aged 8-11.9 years enrolled in the Vascular Function Intervention Trial (ISRCTN74331412/NCT01718054) underwent baseline assessment of endothelium-dependent and -independent vasodilatation. All children were determined clinically well at assessment, hydroxyurea naive, on no long-term medication and not receiving chronic blood transfusions. Blood pressure and vasomotion were assessed after 10 minutes recumbent rest in a temperature controlled room between 08-13:00 hrs. An identical protocol as published in children (Donald & Charakida et al. Eur Heart J; 2010: 31; 1502-10) was used. In brief, brachial arterial endothelium dependent dilatation was assessed by 1 of 3 trained technicians using ultrasound imaging (Ultrasonix SonixTouch with a 12Mz probe & stereotactic holder) to assess flow-mediated dilatation (FMD) in response to reactive hyperaemia induced after release of transient blood pressure cuff occlusion (5 min, 200 mmHg, Hokanson, USA) using an automated air regulator (Logan Research, UK). Automated B-mode image edge detection was used to measure maximum change in arterial diameter (Brachial Tools) expressed as a percentage of resting baseline diameter (FMDmax). Endothelium-independent responses to 2.5µg sub-lingual glyceryl-trinitrate (GTN) were also assessed. All recordings were over-read by an experienced researcher in the UK. Venepuncture for full blood count, clinical chemistry and amino acids was conducted after FMD assessment. Results Patient characteristics are described in Table 1. Mean brachial artery diameter at baseline was 2.61mm (95% CI 2.55 – 2.67mm). Mean FMDmax was 7.70% (95% CI 7.09 – 8.32%). Endothelium-independent vasodilation (GTNmax) was 4.15% (95% CI 3.83 – 4.47%). The FMDmax response was on greater than the GTNmax response (Figure 1). No effect of room or skin temperature on FMDmax or GTNmax was observed. There was a strong inverse association between baseline artery diameter and FMDmax (-3.46, P<0.001) (Figure 2). The time to peak brachial artery diameter in response to hyperaemia was positively skewed (median 55s (IQR: 43-79s)) and was not associated with FMDmax. The only patient characteristic associated with FMDmax was age with a non-significant inverse correlation (-0.52, P=0.06) but was reduced when adjusting for baseline diameter. Baseline heart rate was positively associated with FMDmax and GTNmax (P=0.01 & 0.025). Discussion We have characterised peripheral vascular function in a large cohort of children with SCA. Mean FMDmax was slightly lower than that observed in predominantly Caucasian non-SCA British children of similar age (8.1% [SD3.4]) (Donald & Charakida et al. Eur Heart J 2010: 31; 1502-10), but higher than reported in 21 older French children with SCA (5.6 +/- 0.2) (Montalembert et al. Haematol 2007: 92; 1709-10) which might reflect deterioration of endothelial function with age. There was no apparent association between FMDmax and hemolytic markers or with nutritional status at baseline. Recruitment and assessment of appropriate local non-SCA controls for comparison is planned. Amino acid analyses are ongoing. Disclosures: No relevant conflicts of interest to declare.

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Study of endothelial function in pregnant women with gestational diabetes mellitus by flow mediated dilation of brachial artery

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20202315 ◽

2020 ◽

Vol 9 (6) ◽

pp. 2377

Author(s):

Nidhi Pandey ◽

Poonam Goel ◽

Anita Malhotra ◽

Reeti Mehra ◽

Navjot Kaur

Keyword(s):

Gestational Diabetes ◽

Endothelial Function ◽

Pregnant Women ◽

Brachial Artery ◽

Vascular Function ◽

Post Partum ◽

Control Group ◽

Flow Mediated Dilation ◽

The Mean ◽

The Difference

Background: The objective of the study was to assess vascular function in normal pregnant women and women with gestational diabetes and to study its temporal relationship with gestational age at 24-28-week POG and at 36-38-week POG and changes in FMD in postpartum period.Methods: Assessment of vascular function was done at 24-28-week POG, 36-38-week POG and at 6-12-week postpartum by flow mediated dilation of brachial artery in 37 healthy pregnant women and 37 pregnant women with GDM.Results: In GDM group mean FMD at 24-28 weeks of POG, at 36-38 weeks POG was lower as compared to the control group (11.225±6.20,8.464±6.09 versus 14.49±5.21, 10.898±4.12) although the difference in mean FMD in two groups was not statistically significant. It was found that the decrease in FMD at 36-38-week POG as compared to 24-28 weeks POG was statistically significant in both the groups (p<0.001).Conclusions: This study revealed that when endothelial function as assessed by FMD was compared at different period of gestation, the mean decrease in FMD at 36-38-week POG as compared to 24-28-week POG and 6-week post-partum was statistically significant in patients with GDM and as well as the control group, however this trend of change was same in both the groups and was not statistically significant when compared between the two group (GDM versus control). A negative correlation of FMD was found with BMI, and HBA1c, that was stronger in GDM group.

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Effects of polycythemia on systemic endothelial function in chronic hypoxic lung disease

Journal of Applied Physiology ◽

10.1152/japplphysiol.01204.2010 ◽

2011 ◽

Vol 110 (5) ◽

pp. 1196-1203 ◽

Cited By ~ 12

Author(s):

Laurent Boyer ◽

Vicky Chaar ◽

Gabriel Pelle ◽

Bernard Maitre ◽

Christos Chouaid ◽

...

Keyword(s):

Endothelial Function ◽

Brachial Artery ◽

Blood Viscosity ◽

Vascular Function ◽

Venous Occlusion ◽

Chronic Obstructive ◽

Brachial Artery Diameter ◽

Obstructive Pulmonary Disease ◽

Vasoconstrictor Response ◽

No Release

Chronic obstructive pulmonary disease (COPD) is a major risk factor for cardiovascular disease. Polycythemia, a common complication of hypoxic COPD, may affect systemic vascular function by altering blood viscosity, vessel wall shear stress (WSS), and endothelium-derived nitric oxide (NO) release. Here, we evaluated the effects of hypoxia-related polycythemia on systemic endothelial function in patients with COPD. We investigated blood viscosity, WSS, and endothelial function in 15 polycythemic and 13 normocythemic patients with COPD of equal severity, by recording brachial artery diameter variations in response to hyperemia and by using venous occlusion plethysmography (VOP) to measure forearm blood flow (FBF) responses to a brachial artery infusion of acetylcholine (ACh), bradykinin (BK), sodium nitroprusside (SNP), substance P (SP), isoptin, and N-monomethyl-l-arginine (l-NMMA). At baseline, polycythemic patients had higher blood viscosity and larger brachial artery diameter than normocythemic patients but similar calculated WSS. Flow-mediated brachial artery vasodilation was increased in the polycythemic patients, in proportion to the hemoglobin levels. ACh-induced vasodilation was markedly impaired in the polycythemic patients and negatively correlated with hemoglobin levels. FBF responses to endothelium- (BK, SP) and non-endothelium-dependent (SNP, isoptin) vasodilators were not significantly different between the two groups. l-NMMA infusion induced a similar vasoconstrictor response in both groups, in accordance with their similar baseline WSS. In conclusion, systemic arteries in polycythemic patients adjust appropriately to chronic or acute WSS elevations by appropriate basal and stimulated NO release. Overall, our results suggest that moderate polycythemia has no adverse effect on vascular function in COPD.

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Longer-Term Soy Nut Consumption Improves Vascular Function and Cardiometabolic Risk Markers in Older Adults: Results of a Randomized, Controlled Cross-Over Trial

Current Developments in Nutrition ◽

10.1093/cdn/nzab033_058 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 58-58

Author(s):

Lea Tischmann ◽

Tanja Adam ◽

Ronald Mensink ◽

Peter Joris

Keyword(s):

Older Adults ◽

Arterial Stiffness ◽

Endothelial Function ◽

Vascular Function ◽

Ldl Cholesterol ◽

Control Period ◽

Daily Intake ◽

Cardiometabolic Health ◽

Cvd Risk ◽

Randomized Controlled

Abstract Objectives Soy foods may contribute to the beneficial effects of plant-based diets on cardiovascular disease (CVD) risk. However, their effects on vascular function have hardly been investigated. The objective was to investigate if longer-term soy nut consumption improves vascular function and cardiometabolic health in older adults. Methods Twenty-three apparently healthy participants (60–70 years; BMI between 20–30 kg/m2) participated in a randomized, controlled, single-blinded cross-over trial with an intervention (67 g of soy nuts daily providing 25.5 g soy protein) and control period (no nuts) of 16 weeks, separated by eight weeks wash-out. Volunteers followed the Dutch food-based dietary guidelines. At baseline and at 8 and 16 weeks anthropometric measurements and fasting blood samples were collected. Markers of vascular function (i.e., endothelial function, arterial stiffness, and microvascular structure) were assessed at week 16. Results No serious adverse events were reported and the soy nut regime was well tolerated. Body weight remained stable. Serum isoflavone concentrations, a marker of compliance, increased after the intervention period (daidzein: 128.3 ng/mL; 95% CI: 72.6–183.9 ng/mL; P < 0.001 and genistein: 439.8 ng/mL 95% CI: 246.7–632.9 ng/mL; P < 0.001). The brachial artery flow-mediated vasodilation (FMD) response increased by 1.49 pp (95% CI: 0.03–2.95 pp; P = 0.046) following the soy intervention, but no effect was found on the carotid artery reactivity (CAR) response. Arterial stiffness, assessed by carotid-to-femoral pulse wave velocity (PWVc-f), was unchanged. Retinal arteriolar calibers (CRAE), a measure for microvascular structure, tended to improve by 1.42 mm (95% CI: −0.05–2.90 mm; P = 0.059). Soy consumption also lowered serum LDL-cholesterol concentrations by 0.17 mmol/L (95% CI: 0.02–0.32 mmol/L; P = 0.027). HDL-cholesterol and triacylglycerol (TAG) did not change. Finally, office SBP and DBP decreased by 4 mmHg (95% CI: 0–8 mmHg; P = 0.034) and 2 mmHg (95% CI: 1–4 mmHg; P = 0.005), respectively. Conclusions A longer-term daily intake of soy nuts improved endothelial function, office blood pressure, and serum LDL-cholesterol concentrations, suggesting mechanisms by which an increased soy food intake beneficially affects CVD risk in older adults. Funding Sources This study was supported by a grant from the Alpro Foundation.

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Noninvasive Assessment of Endothelium-Dependent Flow-Mediated Dilation of the Brachial Artery

Vascular Medicine ◽

10.1177/1358863x9700200203 ◽

1997 ◽

Vol 2 (2) ◽

pp. 87-92 ◽

Cited By ~ 128

Author(s):

Akimi Uehata ◽

Eric H Lieberman ◽

Marie D Gerhard ◽

Todd J Anderson ◽

Peter Ganz ◽

...

Keyword(s):

Blood Flow ◽

Endothelial Function ◽

Brachial Artery ◽

Vascular Function ◽

Reactive Hyperemia ◽

Intraobserver Variability ◽

Flow Mediated Dilation ◽

Noninvasive Technique ◽

Brachial Artery Diameter ◽

Cuff Occlusion

Coronary atherosclerosis is characterized by an early loss of endothelium-dependent vasodilation. However, the methods of assessing coronary endothelial function are invasive and difficult to repeat over time. Recently, a noninvasive ultrasound method has been widely used to measure flow-mediated dilation in the brachial artery as a surrogate test for endothelial function. We seek to further validate this method of measuring vascular function. The brachial artery diameters and blood flow of 20 normal volunteers (10 males and 10 females) were measured using high resolution (7.5 MHz) ultrasound and strain gauge plethysmography. Flow-mediated endothelium-dependent vasodilation was measured in the brachial artery during reactive hyperemia after 5 minutes of cuff occlusion in the upper arm. The brachial artery diameter increased maximally by 9.7 ± 4.3% from baseline at 1 min after cuff release and blood flow increased by 1002 ± 376%. Five min of cuff occlusion was sufficient to achieve 97 ± 6% of maximal brachial artery dilation and degree of dilation was not different whether the cuff was inflated proximally or distally to the image site. The intraobserver variability in measuring brachial diameters was 2.9 % and the variability of the hyperemic response was 1.4%. In young, healthy men and women, the baseline brachial artery diameter was the only factor that was predictive of the flow-mediated vasodilation response. The brachial noninvasive technique has been further validated by the determination of flow-mediated dilation. This method of assessing endothelial function may help to determine the importance of vasodilator dysfunction as a risk factor in the development of atherosclerosis.

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Vascular Endothelial Function in Midlife/Older Adults Classified According to 2017 American College of Cardiology/American Heart Association Blood Pressure Guidelines

Journal of the American Heart Association ◽

10.1161/jaha.120.016625 ◽

2020 ◽

Vol 9 (17) ◽

Author(s):

Daniel H. Craighead ◽

Kaitlin A. Freeberg ◽

Douglas R. Seals

Keyword(s):

Reactive Oxygen Species ◽

Older Adults ◽

Endothelial Function ◽

Brachial Artery ◽

American Heart Association ◽

American Heart ◽

Heart Association ◽

Flow Mediated Dilation ◽

Oxygen Species ◽

Artery Flow

Background Impaired endothelial function is thought to contribute to the increased cardiovascular risk associated with above‐normal blood pressure (BP). However, the association between endothelial function and BP classified by 2017 American College of Cardiology/American Heart Association guidelines is unknown. Our objective was to determine if endothelial function decreases in midlife/older adults across the 2017 American College of Cardiology/American Heart Association guidelines BP classifications and identify associated mechanisms of action. Methods and Results A retrospective analysis of endothelial function (brachial artery flow‐mediated dilation) from 988 midlife/older adults (aged 50+ years) stratified by BP status (normal BP; elevated BP; stage 1 hypertension; stage 2 hypertension) was performed. Endothelium‐independent dilation (sublingual nitroglycerin), reactive oxygen species–mediated suppression of endothelial function (∆brachial artery flow‐mediated dilation with vitamin C infusion), and endothelial cell and plasma markers of oxidative stress and inflammation were assessed in subgroups. Compared with normal BP (n=411), brachial artery flow‐mediated dilation was 12% ( P =0.04), 15% ( P <0.01) and 20% ( P <0.01) lower with elevated BP (n=173), stage 1 hypertension (n=248) and stage 2 hypertension (n=156), respectively, whereas endothelium‐independent dilation did not differ ( P =0.14). Vitamin C infusion increased brachial artery flow‐mediated dilation in those with above‐normal BP ( P ≤0.02) but not normal BP ( P =0.11). Endothelial cell p47 phox ( P <0.01), a marker of superoxide/reactive oxygen species–generating nicotinamide adenine dinucleotide phosphate oxidase, and circulating interleukin‐6 concentrations ( P =0.01) were higher in individuals with above‐normal BP. Conclusions Vascular endothelial function is progressively impaired with increasing BP in otherwise healthy adults classified by 2017 American College of Cardiology/American Heart Association guidelines. Impaired endothelial function with above‐normal BP is mediated by excessive reactive oxygen species signaling associated with increased endothelial expression of nicotinamide adenine dinucleotide phosphate oxidase and circulating interleukin‐6.

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Gender differences in vascular function and insulin sensitivity in young adults

Clinical Science ◽

10.1042/cs20100223 ◽

2010 ◽

Vol 120 (4) ◽

pp. 153-160 ◽

Cited By ~ 20

Author(s):

Donald R. Dengel ◽

David R. Jacobs ◽

Julia Steinberger ◽

Antoinette M. Moran ◽

Alan R. Sinaiko

Keyword(s):

Gender Differences ◽

Young Adults ◽

Insulin Sensitivity ◽

Brachial Artery ◽

Vascular Function ◽

Adult Population ◽

Density Lipoprotein ◽

Cross Sectional ◽

Brachial Artery Diameter ◽

Significant Difference

To examine influence of insulin resistance and other clinical risk factors for the MetS (metabolic syndrome) on vascular structure and function in young adults. This cross-sectional study was conducted in a cohort of young adults (mean age 22 years) and their siblings participating in a longitudinal study of cardiovascular risk (n=370). Insulin sensitivity was determined by euglycaemic insulin clamp. EDD (endothelium-dependent dilation) was determined by flow-mediated dilation using high-resolution ultrasound imaging of the brachial artery. EID (endothelium-independent dilation) was determined by NTG (nitroglycerine)-mediated dilation. The diameter and cIMT (intima–media thickness) of the carotid artery were also measured. There was no significant difference between males and females for age or body mass index. However, males had significantly higher glucose and triacylglycerol (triglyceride) levels, while the females had significantly higher HDL-C (high-density lipoprotein-cholesterol) and insulin sensitivity (13.00±0.33 compared with 10.71±0.31 mg·kg−1 of lean body mass·min−1, P<0.0001). Although peak EDD was significantly lower (6.28±0.26 compared with 8.50±0.28%, P<0.0001) in males than females, this difference was largely explained by adjustment for brachial artery diameter (P=0.15). Peak EID also was significantly lower in males than females (20.26±0.44 compared with 28.64±0.47%, P<0.0001), a difference that remained significantly lower after adjustment for brachial artery diameter. Males had a significantly greater cIMT compared with females (females 0.420±0.004 compared with males 0.444±0.004 mm, P=0.01), but when adjusted for carotid diameter, there was no significant difference (P=0.163). Although there were gender differences in vascular function and structure in the young adult population examined in this study, many of the differences were eliminated simply by adjusting for artery diameter. However, the lower EID observed in males could not be explained by artery diameter. Future studies need to continue to examine influence of gender on EID and other measures of vascular function.

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Acute ingestion of citrulline stimulates nitric oxide synthesis but does not increase blood flow in healthy young and older adults with heart failure

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00339.2015 ◽

2015 ◽

Vol 309 (11) ◽

pp. E915-E924 ◽

Cited By ~ 23

Author(s):

Il-Young Kim ◽

Scott E. Schutzler ◽

Amy Schrader ◽

Horace J. Spencer ◽

Gohar Azhar ◽

...

Keyword(s):

Nitric Oxide ◽

Heart Failure ◽

Older Adults ◽

Blood Flow ◽

Young Adults ◽

Vascular Function ◽

De Novo ◽

Synthesis Rate ◽

Fasted State

To determine if age-associated vascular dysfunction in older adults with heart failure (HF) is due to insufficient synthesis of nitric oxide (NO), we performed two separate studies: 1) a kinetic study with a stable isotope tracer method to determine in vivo kinetics of NO metabolism, and 2) a vascular function study using a plethysmography method to determine reactive hyperemic forearm blood flow (RH-FBF) in older and young adults in the fasted state and in response to citrulline ingestion. In the fasted state, NO synthesis (per kg body wt) was ∼50% lower in older vs. young adults and was related to a decreased rate of appearance of the NO precursor arginine. Citrulline ingestion (3 g) stimulated de novo arginine synthesis in both older [6.88 ± 0.83 to 35.40 ± 4.90 μmol·kg body wt−1·h−1] and to a greater extent in young adults (12.02 ± 1.01 to 66.26 ± 4.79 μmol·kg body wt−1·h−1). NO synthesis rate increased correspondingly in older (0.17 ± 0.01 to 2.12 ± 0.36 μmol·kg body wt−1·h−1) and to a greater extent in young adults (0.36 ± 0.04 to 3.57 ± 0.47 μmol·kg body wt−1·h−1). Consistent with the kinetic data, RH-FBF in the fasted state was ∼40% reduced in older vs. young adults. However, citrulline ingestion (10 g) failed to increase RH-FBF in either older or young adults. In conclusion, citrulline ingestion improved impaired NO synthesis in older HF adults but not RH-FBF, suggesting that factors other than NO synthesis play a role in the impaired RH-FBF in older HF adults, and/or it may require a longer duration of supplementation to be effective in improving RH-FBF.

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Effect of Integrated Yoga Therapy on Arterial Stiffness: A Pilot Study on Young and Older Adults with Obesity

Integrative Medicine International ◽

10.1159/000477542 ◽

2017 ◽

Vol 4 (1-2) ◽

pp. 85-93 ◽

Cited By ~ 1

Author(s):

Pusuluri Venkata Giri Kumar ◽

Sudheer Deshpande ◽

Aniruddha Joshi ◽

Pooja More ◽

Amit Singh ◽

...

Keyword(s):

Older Adults ◽

Young Adults ◽

Pilot Study ◽

Arterial Stiffness ◽

Radial Artery ◽

Integrated Approach ◽

Stiffness Index ◽

Reflection Index ◽

Yoga Therapy ◽

Paired Samples

Background/Aims: The studies on the effect of integrated yoga therapy have shown significant results in improving the overall health. However, the effect of integrated yoga therapy on arterial stiffness is not yet established. The aim of the study was to investigate the effect of integrated yoga therapy on arterial stiffness measured at the radial artery. Methods: A total of 18 participants were included in the study. The participants were divided into three groups based on their age and body mass index. There were 5 participants in group 1 who were considered as nonobese, 7 younger adults with obesity were included in group 2, and 6 older adults with obesity were included in group 3. A 1-week integrated approach of yoga therapy (IAYT) was given as an intervention to the participants. The pulse data was acquired from participants using Nadi Tarangini at the beginning and end of the yoga program. The stiffness index (SI) and reflection index (RI) were computed from the pulse data. The data were analyzed using the paired-samples t test. Results: There was a significant reduction in SI (p < 0.05) after IAYT in young participants with obesity. There was a significant reduction in BMI after IAYT in older adults, but the SI was only significantly low in young adults. There were no significant changes in RI after IAYT. Conclusion: The pilot study has shown that arterial stiffness measured at the radial artery using Nadi Tarangini has decreased significantly after 1 week of IAYT in young adults with obesity compared to older adults.

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The impact of baseline diameter on flow-mediated dilation differs in young and older humans

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00669.2008 ◽

2008 ◽

Vol 295 (4) ◽

pp. H1594-H1598 ◽

Cited By ~ 42

Author(s):

Dick H. J. Thijssen ◽

Marieke M. van Bemmel ◽

Lauren M. Bullens ◽

Ellen A. Dawson ◽

Nicola D. Hopkins ◽

...

Keyword(s):

Brachial Artery ◽

Vascular Function ◽

Flow Mediated Dilation ◽

Healthy Children ◽

Cuff Inflation ◽

Brachial Artery Diameter ◽

Age Dependent ◽

Older Subjects ◽

The Impact ◽

Baseline Diameter

Flow-mediated dilation (FMD) has become a commonly applied approach for the assessment of vascular function and health, but methods used to calculate FMD differ between studies. For example, the baseline diameter used as a benchmark is sometimes assessed before cuff inflation, whereas others use the diameter during cuff inflation. Therefore, we compared the brachial artery diameter before and during cuff inflation and calculated the resulting FMD in healthy children ( n = 45; 10 ± 1 yr), adults ( n = 31; 28 ± 6 yr), and older subjects ( n = 22; 58 ± 5 yr). Brachial artery FMD was examined after 5 min of distal ischemia. Diameter was determined from either 30 s before cuff inflation or from the last 30 s during cuff inflation. Edge detection and wall tracking of high resolution B-mode arterial ultrasound images was used to calculate conduit artery diameter. Brachial artery diameter during cuff inflation was significantly larger than before inflation in children ( P = 0.02) and adults ( P < 0.001) but not in older subjects ( P = 0.59). Accordingly, FMD values significantly differed in children (11.2 ± 5.1% vs. 9.4 ± 5.2%; P = 0.02) and adults (7.3 ± 3.2% vs. 4.6 ± 3.3%; P < 0.001) but not in older subjects (6.3 ± 3.4% vs. 6.0 ± 4.2%; P = 0.77). When the diameter before cuff inflation was used, an age-dependent decline was evident in FMD, whereas FMD calculated using the diameter during inflation was associated with higher FMD values in older than younger adults. In summary, the inflation of the cuff significantly increases brachial artery diameter, which results in a lower FMD response. This effect was found to be age dependent, which emphasizes the importance of using appropriate methodology to calculate the FMD.

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