Yan, Huimin

Acute exercise appears to have positive influence on arterial function during the recovery period, yet the effect of obesity is poorly understood in recovery. We examined the effects of an acute bout of exercise on arterial function in obese versus healthy weight individuals. Young (23 yr), lean (n=38, BMI=22.3 kg/m 2 ) and obese (n=20, BMI=34.0 kg/m 2 ) individuals had arterial measurements obtained at rest, and 15 and 30 min following a maximal bout of aerobic exercise. Arterial tonometry and ultrasound were used to obtain central BP, arterial compliance and stiffness (beta stiffness, elastic modulus (Ep), and central pulse wave velocity (PWV)). Despite similar central mean BP, the obese group had higher cPWV following exercise. Beta stiffness and Ep responded similarly to exercise between groups. Arterial compliance was higher in obese but the response in recovery was similar between groups. Lean Obese Pre 15‐min post 30‐min post Pre 15‐min post 30‐min post Mean aortic BP 82 83 82 87 86 87 Central PWV 5.67 5.46 5.35 5.84 6.11 6.16 Beta Stiffness 5.89 6.34 5.78 4.88 6.04 5.31 Elastic Modulus 69 75 67 67 78 66 In this young cohort, obesity was associated with increased central arterial stiffness, independent of BP, but higher arterial compliance. This suggests that measures of arterial stiffness provide differential information potentially associated with where in the arterial tree measures were made.

Introduction Heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS), measures of autonomic nervous system function, are associated with cardiovascular (CV) outcome. African Americans (AA) have an increased prevalence of CV disorders in comparison to Caucasians (C). Purpose To determine race specific responses in BPV, BRS and HRV before and after maximal exercise. Methods 37 AA and 37 C (24 years) underwent maximal exercise on a cycle ergometer. BPV, BRS and HRV measurements were assessed using finger plethysmography before and after exercise. Data were log transformed and pre‐and post‐max test values were compared by race. Results Acute exercise significantly decreased BRS, LF‐HRV and HF‐HRV and significantly increased LF/HF‐HRV in both AA and C. With exercise, C significantly decreased measures of BRS and HRV more compared to AA; BRS‐SAPRRI transfer mean (C: 2.65±.54 to 1.09±.81 versus AA: 2.70±.40 to 1.70±.92), BRS‐down down (C: 3.21±.55 to 1.74±.49 versus AA: 3.28±1.0 to 2.2±.71), HRV‐LF (C: 6.39±.86 to 3.68±1.42 versus AA: 6.37±1.24 to 5.18±2.14) and HRV‐HF (C: 7.38±1.23 to 3.53±1.73 versus AA: 7.51±1.09 to 5.38±2.16). Conclusion C exhibited increased vagal withdrawal and greater reductions in BRS compared to AA in response to acute exercise. The impact of these racial differences in autonomic control on CV risk needs further investigation.

New Findings What is the central question of this study? The aim of the study was to evaluate the effect of acute induced systemic inflammation on endothelial function, wave reflection and arterial function in older adults. What is the main finding and its importance? Acute inflammation induced by influenza vaccination did not affect endothelial function in older adults. These findings have never been shown in older adults, and they emphasize the importance of vascular function during systemic arterial inflammation. Acute inflammation reduces flow‐mediated vasodilatation and increases arterial stiffness in young healthy individuals. However, this response has not been studied in older adults. The aim of this study, therefore, was to evaluate the effect of acute induced systemic inflammation on endothelial function and wave reflection in older adults. Furthermore, an acute bout of moderate‐intensity aerobic exercise can be anti‐inflammatory. Taken together, we tested the hypothesis that acute moderate‐intensity endurance exercise, immediately preceding induced inflammation, would be protective against the negative effects of acute systemic inflammation on vascular function. Fifty‐nine healthy volunteers between 55 and 75 years of age were randomized to an exercise or a control group. Both groups received a vaccine (induced inflammation) and sham (saline) injection in a counterbalanced crossover design. Inflammatory markers, endothelial function (flow‐mediated vasodilatation) and measures of wave reflection and arterial stiffness were evaluated at baseline and at 24 and 48 h after injections. There were no significant differences in endothelial function and arterial stiffness between the exercise and control group after induced inflammation. The groups were then analysed together, and we found significant differences in the inflammatory markers 24 and 48 h after induction of acute inflammation compared with sham injection. However, flow‐mediated vasodilatation, augmentation index normalized for heart rate (AIx75) and β‐stiffness did not change significantly. Our results suggest that acute inflammation induced by influenza vaccination did not affect endothelial function in older adults.