Exercise, Vascular Function and Cardiovascular Risk in a Sedentary Workforce

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Context Endothelial dysfunction is associated with cardiovascular risk, which in men has been linked with a paucity of bone marrow-derived endothelial progenitor cells (EPCs). Objective Our purpose was to determine predictors of endothelial function and cardiovascular risk for women with sedentary occupations and no regular exercise. Design, Setting and Participants We recruited 90 women (age range 22-63 years) who reported no routine exercise (71% overweight or obese) with no history of cardiovascular disease: 43 had 1 cardiovascular risk factor. Main Outcome Measures Endothelial function was determined by brachial artery flow-mediated dilation following 5 minutes of forearm ischemia. Peripheral blood mononuclear cells were evaluated for EPC colony formation after five days of culture in fibronectin-coated wells. Treadmill stress testing was performed with gas exchange analysis at peak exercise (peak VO2) to assess level of fitness. Results Brachial artery reactivity correlated positively with peak VO2 (r=0.4483, P<0.0001) and inversely with Framingham risk score (r=-0.3542, P=0.0007), age (r=-0.3420, P=0.0010), body-mass index (r=-0.3065, P=0.0035), C-reactive protein (r=-0.2220, P=0.0400) and marginally with follicle-stimulating hormone, total cholesterol and systolic blood pressure. EPC colonies were not associated with brachial artery flow-mediated dilation (r=0.0025, P=0.9810) or with Framingham risk score (r=-0.0144, P=0.8940), even when data were stratified by menopausal status and absence of therapies that might effect either measurement. By multiple linear regression analysis with stepwise modeling, peak VO2 (P=0.0003) remained as the best independent predictor of brachial artery reactivity. Peak VO2 was inversely associated with risk factor prevalence and predictive of Framingham risk score (r=-4455, P<0.0001), especially for obese women (r=-0.5414, P=0.0003). Conclusions Endothelial function is significantly associated with cardiovascular risk in sedentary women; EPCs are associated with neither. Instead, level of fitness is the dominant predictor of endothelial function and cardiovascular risk, even in overweight and obese women.