Relationships between Physical Fitness and Endothelial Vascular Control in Elderly Men and Women

Abstract

This study investigates correlations between physical fitness and endothelial vascular control and its underlying mechanisms in older men and women. A total of 38 healthy older adults (18 men, age 72.2±3.2 yr; 18 women, age 73.5±2.8 yr) were studied. All subjects received a three-minute step test to determine their cardiopulmonary index (CPI). Both percentage of body fat and distribution of body water, including total body water, intracellular water (ICW), and intracellular water (ECW), were measured by bioelectrical impedance analysis. Hemodynamic characteristics in the arterial and venous vessel were analyzed by impedance plethysmography, whereas skin vascular endothelial function was measured using a laser Doppler perfusion with iontophoresis. Our results showed that 1) hyperemic arterial flow, acetylcholine (ACh)-induced cutaneous perfusion, and the ratio of ACh to sodium nitroprusside (SNP)-induced cutaneous perfusion was positively correlated with CPI in both older men and women; 2) a lower CPI was accompanied by a higher ECW/ICW ratio in older women (r= −0.580), while a higher CPI was associated with a lower body fat in older men (r= −0.496); and 3) the ratio of ACh to SNP-induced cutaneous perfusion was negatively correlated with the ECW/ICW ratio in the female subjects(r= −0.538) and the body fat in the male subjects (r= −0.445). We conclude that endothelial vascular function can influence cardiopulmonary fitness in the elderly. Moreover, the age-related declines of physical fitness and endothelium-dependent vasodilation may be associated with the sex-related changes in body water distribution and fat percentage.