Objective: Some individuals with cardiovascular risk are unable to achieve even the lower internationally recommended level of physical activity (PA). We aimed to study the impact of a lower-than-advised level of PA on small artery vascular function and oxidative stress in overweight and obese postmenopausal women.
Methods: Forty-seven overweight and obese postmenopausal women completed a 4-month program of 1-hour low-intensity PA for 2 days per week. Before and after the intervention, PA level (metabolic equivalent tasks/h/wk), endogenous antioxidant status (superoxide dismutase and erythrocyte lysate and glutathione peroxidase erythrocyte lysate concentrations, superoxide dismutase plasma and glutathione peroxidase plasma [GPXa] activities, and oxidized low-density lipoprotein), asymmetrical dimethylarginine concentrations, endothelial function by small artery reactive hyperemia index (saRHI), and resting heart rate (RHR) were assessed.
Results: After the intervention, a significant increase in GPXa and decreases in asymmetrical dimethylarginine concentrations and RHR (P < 0.001 for all) were observed. Increases in PA were positively associated with increases in saRHI (r = 0.330, P = 0.027) and GPXa (r = 0.299, P = 0.05) and a decrease in RHR (r = -0.297, P = 0.047). Multivariate analyses showed that the independent predictors of saRHI improvement were an increase in PA (β = 2.63; 95% CI, 1.24-4.19; P = 0.019), a decrease in RHR (β = 1.96; 95% CI, 1.01-5.03; P = 0.048), and an increase in GPXa (β = 2.64; 95% CI, 1.18-5.08; P = 0.021).
Conclusions: Even low-intensity PA improves antioxidant capacity, RHR, and saRHI in postmenopausal women. Advising postmenopausal women to increase their PA at any level seems warranted based on our preliminary and hypothesis-generating data.