Body Composition and Physical Fitness Affect Central Hemodynamics in Young Children

Objective: Central hemodynamics are related to cardiovascular (CV) outcomes in adults, but associations with childhood CV risk remain unclear. The study aimed to investigate the association of obesity, physical activity, and fitness with parameters of central pulse wave reflection in young prepubertal children.Methods: In this cross-sectional study, 1,324 primary school children (aged 7.2 ± 0.4 years) were screened for parameters of pulse wave reflection such as augmentation index (AIx), central pulse pressure (CPP), body mass index (BMI), and cardiorespiratory fitness (CRF) by standardized procedures for children.Results: The mean AIx and AIx@75 were 22.2 ± 7.7 and 29.2 ± 9.2%, respectively. With each unit increase in BMI, AIx [−0.226 (−0.328; −0.125)%] and AIx@75 [−0.444(−0.660; −0.229)%] decreased, whereas peak forward pulse wave increased (p < 0.001). Increasing BMI was associated with higher CPP, but did not remain significant after adjustment for CRF and heart rate. One unit increase in CRF was associated with lower AIx@75 [−0.509(−0.844; −0.173)%, p = 0.003] and lower reflection magnitude [RM: −0.559 (−0.890; −0.227), p = 0.001], independent of body weight and height. Girls had significantly higher AIx, AIx@75, peak backward pulse wave, and RM compared with boys.Conclusion: Childhood obesity was associated with higher CPP but lower augmentation of the reflected pulse wave in children. Assessment of central blood pressures appears to be a valuable asset to childhood CV risk screening. The validity of augmentation indices during childhood development and the association with early vascular aging in children need to be verified in long-term follow-up studies. Physical activity and fitness have the potential to improve vascular hemodynamics in susceptible children and, thus, counteract vascular aging.Trial registry: ClinicalTrials.gov: Exercise and Arterial Modulation in Youth. Identifier: NCT02853747; URL: https://clinicaltrials.gov/ct2/show/NCT02853747.

Vascular Responses to High-Intensity Battling Rope Exercise between the Sexes

The purpose of the study was to assess high-intensity battling rope exercise (HI-BRE) on hemodynamics, pulse wave reflection and arterial stiffness during recovery and between sexes. Twenty-three young, healthy resistance-trained individuals (men: n = 13; women: n = 10) were assessed for all measures at Rest, as well as 10-, 30-, and 60-minutes following HI-BRE. A one-way repeated measures ANOVA was used to analyze the effects of HI-BRE across time (Rest, 10, 30, and 60-minutes) on all dependent variables. Significant main effects were analyzed using paired t-tests with a Sidak correction factor. Significance was accepted a priori at p 0.05. There were significant reductions in hemodynamic measures of diastolic blood pressure (BP) in women, but not men following HI-BRE at 30 minutes. Further, measures of pulse wave reflection, specifically those of the augmentation index (AIx) and wasted left ventricular energy (ΔEw), were significantly increased in both men and women for 60 minutes, but changes were significantly attenuated in women suggesting less ventricular work. There were also significant increases in arterial stiffness in regard to the aorta and common carotid artery that were fully recovered by 30 and 60 minutes, respectively with no differences between men and women. Thus, the primary findings of this study suggest that measures of hemodynamics and pulse wave reflection are collectively altered for at least 60 minutes following HI-BRE, with women having attenuated responses compared to men.

Effects of aerobic, resistance and concurrent exercise on pulse wave reflection and autonomic modulation in men with elevated blood pressure

The acute effects of exercise modes on pulse wave reflection (PWR) and their relationship with autonomic control remain undefined, particularly in individuals with elevated blood pressure (BP). We compared PWR and autonomic modulation after acute aerobic (AE), resistance (RE), and concurrent exercise (CE) in 15 men with stage-1 hypertension (mean ± SE: 34.7 ± 2.5 years, 28.4 ± 0.6 kg/m2, 133 ± 1/82 ± 2 mmHg). Participants underwent AE, RE, and CE on different days in counterbalanced order. Applanation tonometry and heart rate variability assessments were performed before and 30-min postexercise. Aortic pressure decreased after AE (− 2.4 ± 0.7 mmHg; P = 0.01), RE (− 2.2 ± 0.6 mmHg; P = 0.03), and CE (− 3.1 ± 0.5 mmHg; P = 0.003). Augmentation index remained stable after RE, but lowered after AE (− 5.1 ± 1.7%; P = 0.03) and CE (− 7.6 ± 2.4% P = 0.002). Systolic BP reduction occurred after CE (− 5.3 ± 1.9 mmHg). RR-intervals and parasympathetic modulation lowered after all conditions (~ 30–40%; P < 0.05), while the sympathovagal balance increased after RE (1.2 ± 0.3–1.3 ± 0.3 n.u., P < 0.05). Changes in PWR correlated inversely with sympathetic and directly with vagal modulation in CE. In conclusion, AE, RE, and CE lowered central aortic pressure, but only AE and CE reduced PWR. Overall, those reductions related to decreased parasympathetic and increased sympathetic outflows. Autonomic fluctuations seemed to represent more a consequence than a cause of reduced PWR.

Peripheral artery disease impairs myocardial perfusion through increasing pulse wave reflection: the Northern Shanghai study

Background Peripheral artery disease (PAD) is prevalent and substantially contributes to cardiovascular mortality particularly in the elderly, although the pathophysiological impact of PAD on heart itself still needs further investigation. In theory, PAD can increase pulse wave reflection which is an important determinant of subendocardial viability ratio (SEVR), a valuable estimate of myocardial perfusion as indicated by previous invasive studies. Thus, we hypothesize that PAD impairs myocardial perfusion through increasing pulse wave reflection. In this study, we aim to test this hypothesis in a large cohort from the Northern Shanghai Study. Methods A total of 2947 community-dwelling elderly Chinese (43.6% male, mean age: 71.3±5.9 years) were recruited. Ankle-brachial index were measured with the VP1000 device and used to diagnose PAD. Pulse wave reflection was estimated as aortic augmentation pressure (AP). Aortic BP, AP and SEVR were assessed by radial applanation tonometry. Multiple linear regression with SEVR and AP as dependent variable and PAD as independent variable, meanwhile adjusted for other covariates, were performed, respectively. Results 375 (12.7%) participants presented PAD. Compared to subjects without PAD, those with PAD showed significantly lower SEVR (126 vs. 132, P&lt;0.001) but higher AP (19 vs. 17 mmHg, P&lt;0.001). Multiple regression analysis revealed that both SEVR (regression coefficient [B] = −1.69, P=0.04, R2=0.61) and AP (B=1.19, P=0.04, R2=0.56) significantly associated with PAD, respectively. However, the association between SEVR and PAD was abolished when further adjusted for AP (B=−0.49, P=0.52). Similar results were obtained when inter-leg systolic BP difference was used to diagnose PAD. Conclusions PAD significantly and independently associates with myocardial perfusion; moreover, this association is mediated by increased pulse wave reflection. These findings provide a new dimension for understanding the pathophysiological mechanisms of cardiac damage of PAD. Funding Acknowledgement Type of funding source: None