Association between self-reported physical activity and vascular reactivity in postmenopausal women

Short-term exercise training has been associated with improved endothelial-dependent vasodilation, but the impact of long-term habitual physical activity on vascular reactivity is not established. We studied the correlation between self-reported, habitual physical activity and vasoreactivity in non-smoking, non-diabetic, postmenopausal women (n=34, mean age 65.6+/-7.4 years). Vasoreactivity was evaluated by the percentage and absolute change in brachial artery diameter in response to reactive hyperemia induced by occlusion-release, and in response to cold pressor testing (CPT). Habitual physical activity was assessed by a standardized questionnaire based on participant recall. Our results indicate that 64.7% of the women were exercising-to-sweat > or =1x/week, 4.8 flights of stairs were climbed/day, 5.0 city blocks were walked/day and 29.4% participated in moderately physically demanding daily activity. There was a significant association between the number of city blocks walked daily and exercising-to-sweat > or =1x/week with brachial artery percentage and absolute change to CPT (P<0.05). Women who reported a moderately physically demanding daily activity had a significantly greater brachial reactivity percentage change in response to CPT compared with those performing less demanding daily activity (2.0+/-3.6 versus 1.4+/-7.0%, P<0.05). The response to reactive hyperemia was also greater in those women reporting moderately physically demanding daily activity compared to less active women (6.5+/-5.4 versus 5.8+/-5.9%, P=n.s.), but this did not reach statistical significance. Stepwise, multivariate analysis adjusting for body mass index and HDL-cholesterol eliminated the association between physical activity and brachial reactivity in response to CPT, suggesting that physical activity may affect vasoreactivity via these mechanisms. This study suggests that moderate levels of self-reported physical activity are associated with a greater brachial reactivity in response to CPT and supports the recommendation that moderate intensity physical activity may be cardioprotective in postmenopausal women.