Regular aerobic exercise prevents and restores age-related declines in endothelium-dependent vasodilation in healthy men

Background-In sedentary humans endothelium-dependent vasodilation is impair ed with advancing age contributing to their increased cardiovascular risk, whereas endurance-trained adults demonstrate lower age-related risk. We det ermined the influence of regular aerobic exercise on the age-related declin e in endothelium-dependent vasodilation. Methods and Results-In a cross-sectional study, 68 healthy men 22 to 35 or 50 to 76 years of age who were either sedentary or endurance exercise-train ed were studied. Forearm blood flow (FBF) responses to intra-arterial infus ions of acetylcholine and sodium nitroprusside were measured by strain-gaug e plethysmography. Among the sedentary men, the maximum FBF response to ace tylcholine was 25% lower in the middle aged and older compared with the you ng group (P<0.01). In contrast, there was no age-related difference in the vasodilatory response to acetylcholine among the endurance-trained men. FBF at the highest acetylcholine dose was almost identical in the middle aged and older (17.3+/-1.3 mL/100 mt tissue per minute) and young (17.7+/-1.4 mL /100 mt tissue per minute) endurance-trained groups. There were no differen ces in the FBF responses to sodium nitroprusside among the sedentary and en durance-trained groups. In an exercise intervention study, 13 previously se dentary middle aged and older healthy men completed a 3-month, home-based a erobic exercise intervention (primarily walking). After the exercise interv ention, acetylcholine-mediated vasodilation increased approximate to 30% (P <0.01) to levels similar to those in young adults and middle aged and older endurance-trained men. Conclusions-Our results indicate that regular aerobic exercise can prevent the age-associated loss in endothelium-dependent vasodilation and restore l evels in previously sedentary middle aged and older healthy men. This may r epresent an important mechanism by which regular aerobic exercise lowers th e risk of cardiovascular disease in this population.