Moderated Poster Session VI. Exercise Physiology

M428 Relationship of self-reported habitual physical activity and brachial artery flowmediated dilation in healthy adults M Polovina, M Ostojic, V Giga, T Potpara, N Mujovic, M Grujic Institute for Cardiovascular Diseases, Belgrade, Serbia Topic: Physical activity Background: Exercise training improves endothelial function in adults with increased cardiovascular risk. The influence of leisure-time physical activity on endothelial function in healthy grown-up individuals is less well established. Methods: We analysed association of self-reported daily habitual physical activity with brachial artery flow-mediated dilation (FMD) in 115 healthy individuals (age: 21 to 67 yrs, 55 male). Based on self-reported habitual physical activity, participants were divided in 2 subgroups ’ Subgroup 1 (n=59): 30 min of daily brisk walking recreational sports (jogging, bicycling, swimming’Î) and Subgroup 2 (n=56): sedentary individuals (<30 min of daily physical activity). Maximal FMD value (FMD%) and FMD time-course (time to the maximal endotheliumdependent dilation) were determined using high-resolution vascular ultrasound, with offline measurements of brachial artery diameter every 10 seconds, 0 to 240 seconds after cuff release. Results: Physically active individuals achieved maximal endothelium dependent dilation faster than sedentary individuals (Subgroup 1: 59.5 11.2 seconds versus Subgroup 2: 82.7 16.7 seconds, p<0.001), and their maximal FMD% was higher (Subgroup 1: 7.3 2.9% versus Subgroup 2: 5.7 2.3%, p=0.001). In the multivariate analysis of the whole group, after adjustments for age, sex, brachial artery diameter, body mass index, total serum cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, serum creatinine, glucose, high-sensitivity C-reactive protein, systolic and diastolic blood pressure, heart rate, and smoking, physical activity emerged as a multivariate determinant of both FMD time-course (b=-12.03, p<0.001), and FMD% (b=0.96, p=0.023). Conclusions: Habitual physical activity is associated with faster endothelium-dependent dilation, and augmented FMD response, independent of other factors. Regular leisure-time physical activity has beneficial effects on endothelial function in healthy adults.