Although the associations between chronic levels of arterial stiffness and blood pressure (BP) have been fairly well studied, it is not clear whether and how much arterial stiffness is influenced by acute perturbations in BP. The primary aim of this study was to determine magnitudes of BP dependence of various measures of arterial stiffness during acute BP perturbation maneuvers. Fifty apparently healthy subjects, including 25 young (20-40 yr) and 25 older adults (60-80 yr), were studied. A variety of BP perturbations, including head-up tilt, head-down tilt, mental stress, isometric handgrip exercise, and cold pressor test, were used to encompass BP changes induced by physical, mental, and/or mechanical stimuli. When each index of arterial stiffness was plotted with mean BP, all arterial stiffness indices, including cardio-ankle vascular index or CAVI (r = 0.50), carotid-femoral pulse wave velocity or cfPWV (r = 0.51), brachial-ankle pulse wave velocity or baPWV (r = 0.61), arterial compliance (r = -0.42), elastic modulus (r = 0.52), arterial distensibility (r = -0.32), β-stiffness index (r = 0.19), and Young's modulus (r = 0.35) were related to mean BP (all P < 0.01). Changes in CAVI, cfPWV, baPWV, and elastic modulus were significantly associated with changes in mean BP in the pooled conditions, while changes in arterial compliance, arterial distensibility, β-stiffness index, and Young's modulus were not. In conclusion, this study demonstrated that BP changes in response to various forms of pressor stimuli were associated with the corresponding changes in arterial stiffness indices and that the strengths of associations with BP varied widely depending on what arterial stiffness indices were examined.
Aging and diabetes are associated with decreased aerobic fitness, an independent predictor of mortality. Aerobic exercise is prescribed to improve aerobic fitness; however, middle-aged/older diabetic patients often suffer from mobility limitations which restrict walking. Non-weightbearing/low-impact exercise is recommended but the optimal exercise prescription is uncertain. The goal of this randomized controlled trial was twofold: 1) to test if high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT), implemented on a nonweight-bearing all-extremity ergometer, are feasible, well-tolerated and safe in middle-aged/older adults with type 2 diabetes; and 2) to test whether all-extremity HIIT is more effective in improving aerobic fitness than MICT. A total of 58 sedentary individuals with type 2 diabetes (46 to 78 years; 63±1) were randomized to all-extremity HIIT (n=23), MICT (n=19) or non-exercise control (CONT; n=16). All-extremity HIIT and MICT, performed 4×/week for 8 weeks under supervision, resulted in no adverse events requiring hospitalization or medical treatment. Aerobic fitness (VO 2peak) improved by 10% in HIIT and 8% in MICT and maximal exercise tolerance increased by 1.8 and 1.3 min, respectively (P≤0.002 vs. baseline; P≥0.9 for HIIT vs. MICT). In conclusion, all-extremity HIIT and MICT are feasible, well-tolerated and safe and result in similar improvements in aerobic fitness in middle-aged/older individuals with type 2 diabetes. These findings have important implications for exercise prescription for diabetic patients; they indicate
These results suggest that the techniques used to assess arterial stiffness may not be interchangeable in clinical and research settings and that comparisons of findings obtained with different arterial stiffness measures should be conducted with caution.
<b><i>Background:</i></b> A variety of arterial stiffness measures have been used to assess the impacts of disease states and various interventions without clear consensus among them. One of the primary problems faced by investigators conducting systematic reviews and meta-analyses is the lack of standardized methodology with a same unit to evaluate and compare investigations using different arterial stiffness measures. Therefore, the purpose of this study was to derive and summarize standardized equations to convert commonly used image-based measures of arterial stiffness to local pulse wave velocity (PWV). <b><i>Methods:</i></b> We first conducted a literature search to obtain and summarize conversion equations in the published literature such that these equations can be found in one convenient location. Then, we generated regression equations using the data collected in a well-controlled laboratory-based study, in which all measures of arterial stiffness were obtained in 49 apparently healthy participants. <b><i>Results:</i></b> All literature-based conversion equations produced similar local PWV values and were moderately and significantly correlated with directly measured carotid-femoral PWV (cfPWV) with a Pearson’s <i>r</i> ranging from 0.41 to 0.50. The local PWV using laboratory-based equations were modestly associated with cfPWV (<i>r</i> = 0.39–0.49) with an exception of incremental elastic modulus (<i>r</i> = 0.15, <i>p</i> > 0.05). <b><i>Conclusion:</i></b> Commonly used measures of ultrasound-based arterial stiffness can be converted to local PWV and compared with a reference standard measure of arterial stiffness.
BackgroundElevated android body fat increases the risk of developing cardiometabolic diseases. Postprandial hyperglycemia contributes to the proatherogenic metabolic state evident in android adiposity. Due to the insulinotropic effect of milk‐derived proteins, postprandial hyperglycemia has been shown to be reduced with the addition of dairy products. The purpose of this study was to determine whether one serving of nonfat milk added to an oral glucose tolerance test (OGTT) could attenuate postprandial hyperglycemia in individuals with elevated android adiposity and whether these improvements would be associated with metabolic and/or peripheral hemodynamic effects.MethodsIn this placebo‐controlled, randomized, crossover experimental study, 29 overweight/obese adults (26 ± 1 year) consumed an OGTT beverage (75 g glucose) combined with either nonfat milk (227 g) or a placebo control (12 g lactose + 8 g protein + 207 g water) that was matched for both carbohydrate and protein quantities.ResultsIn the whole sample, blood glucose and insulin concentrations increased over time in both trials with no significant differences between trials. Relative increases in peak blood glucose response were significantly related to android body fat (p < 0.05). The subjects in the highest tertiles of android body fat displayed attenuated hyperglycemic responses as well as improvements in flow‐mediated dilation (FMD) after milk intake.ConclusionsA single serving of nonfat milk may attenuate acute hyperglycemia in individuals with elevated android body fat offering a simple and convenient option for managing elevations in blood glucose.
Arterial stiffness and wave reflection are associated with increased risk for cardiovascular disease (CVD), while aerobic exercise is known to decrease CVD risk. The effects of chronic aerobic exercise training on arterial stiffness and wave reflection have been extensively studied, but data on the acute effects of aerobic exercise on these measures are primarily based on men and are limited and conflicting. The purpose of this study was to examine the sex‐specific acute vascular responses to high‐intensity interval training (HIIT), moderate‐intensity continuous training (MICT) and low‐intensity continuous training (LICT) in young adults. Thirty healthy adults, 15 young men and 15 premenopausal women (21.5±0.4 vs. 21.4±0.7 years of age, means ± SE, P =0.9) participated in this randomized crossover study. The SphygmoCor Xcel device (AtCor medical) was employed to assess arterial stiffness using carotid to femoral pulse wave velocity (cfPWV) and wave reflection using augmentation index (AIx). Measures of cfPWV and AIx were obtained prior to exercise (PreE), following the end of a single bout of HIIT, MICT and LICT on the treadmill (PostE), and following recovery from exercise. HIIT consisted of 4 × 4‐min intervals at 90% peak heart rate (HRpeak) interspersed by recovery bouts at 70% HRpeak for a total of 40 min, whereas MICT and LICT consisted of 47 min at 70% and 50% HRpeak, respectively. cfPWV remained unchanged in response to a single bout of exercise, regardless of exercise intensity or sex (5.5±0.1 vs. 5.5±0.1 vs. 5.4±0.1 m/s, PreE vs. PostE vs. recovery; P=0.2 for main effect of time). AIx decreased following recovery compared with PreE and PostE (P≤0.003), but this response was not influenced by exercise intensity or sex (10.3±1.7 vs. 9.0±1.7 vs. 5.0±1.5 %, PreE vs. PostE vs. recovery; P<0.0001 for main effect of time; P=0.8 for sex × exercise × time). In conclusion, exercise intensity and sex do not modulate central arterial stiffness and wave reflection following a single bout of aerobic exercise. Central arterial stiffness is unaffected by acute exercise, whereas wave reflection decreases following recovery from exercise.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.