ABSTRACT

　Aging-induced deterioration of arterial stiffness is decreased by aerobic exercise training, and increased nitric oxide （NO） production is involved in this effect. Apelin promotes NO production via upregulation of endothelial NO synthase, resulting in improvement of arterial stiffness. However, the time-dependent effects of aerobic exercise training on circulating apelin levels remain unclear. 　PURPOSE: This study aimed to determine whether the changes in circulating apelin levels by aerobic exercise training may be a novel predictive biomarker for the decrease in arterial stiffness in middle-aged and older adults. 　METHODS: Twenty Japanese healthy middle-aged and older subjects（ 66±1 years）were randomly divided into two groups: exercise intervention and sedentary controls. Subjects in the training group completed 8-week of middle-intensity aerobic exercise training. We evaluated plasma apelin levels and brachial-ankle pulse wave velocity （baPWV） , measured every 2 weeks for 8-week in the training group. RESULTS: Plasma apelin levels were significantly increased after 4-week intervention （P<0.05） . However, baPWV was gradually declined from baseline to 8-week and significantly decreased after 8-week intervention （P<0.05） . Interestingly, the exercise training?induced increase in plasma apelin levels before and after 4-week exercise training was negatively correlated with the decrease in baPWV before and after 8-week exercise training（ r=-0.700, P<0.05） . 　CONCLUSION: These results suggest that the plasma apelin levels were increased at the early stage of exercise training intervention and was associated with exercise training-induced alternation of arterial stiffness in middle-aged and older adults. Thus, plasma apelin levels may be a predictive biomarker of exercise training-induced improvement of arterial stiffness in middle-aged and older adults.

DECENTE SPORTS SCIENCE Vol.42/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE