Enhanced endothelium-dependent vasodilation in older endurance-trained men

We hypothesized that abnormal endothelium-dependent vasodilation (EDD) found in older otherwise healthy subjects can be attenuated with long-term endurance training. Ten endurance-trained men, 68.5 +/- 2.3 yr old, and 10 healthy sedentary men, 64.7 +/- 1.4 yr old, were studied. Aerobic exercise capacity (VO2max), fasting plasma cholesterol, insulin, and homocysteine concentrations were measured. Master athletes had higher VO2max (42 +/- 2.3 vs. 27 +/- 1.4 ml . kg-(1) . min(-1), P < 0.001), slightly higher total cholesterol (226 +/- 8 vs. 199 +/- 8 mg/dl, P = 0.05), similar insulin, and higher homocysteine (10.7 +/- 1.3 vs. 9.2 +/- 1.4 mu mol/ml, p = 0.02) concentrations. Brachial arterial diameter, determined with vascular ultrasound, during the hyperemic response was greater in the master athletes than in controls (P = 0.005). Peak vasodilatory response was 109.1 +/- 2 vs. 103.6 +/- 2% (P < 0.05) in the athletes and controls, respectively. Endothelium-independent vasodilation in response to nitroglycerin was similar between the two groups. The increased arterial diameter during the hyperemic response correlated significantly with the VO2max in the entire population (r = 0.66, P < 0.002). Our results suggest that long-term endurance exercise training in older men is associated with systemic enhanced EDD, which is even detectable in the conduit arteries of untrained muscle.