Sedentary Lifestyle and Antecedents of Cardiovascular Disease in Young Adults

BACKGROUND: The aim of this study was to determine whether sedentary young individuals are characterized by reductions in determinants of vascular health and insulin sensitivity relative to their physically active, age-matched peers. METHODS: A total of 135 otherwise healthy young men (n = 68) and women (n = 67) <40 years of age (28 +/- 5 years) were studied in this investigation and stratified into three groups based on physical activity status: 1) sedentary (n = 73); 2) physically active (n = 24); and 3) endurance-trained (n = 38). Arterial compliance and flow-mediated dilation were determined by diastolic pulse contour wave analysis and echocardiographic imaging of the brachial artery respectively. Insulin sensitivity was estimated from the homeostasis model for insulin resistance and the 13C-glucose breath test. RESULTS: Both conduit (16.4 +/- 0.5 v 19.5 +/- 0.7 mL/mmHg x 10; P < .01) and resistant (8.5 +/- 0.3 v 10.7 +/- 0.5 mL/mmHg x 100; P < .01) artery compliance were significantly lower in sedentary subjects than in physically active or endurance-trained subjects, whereas flow-mediated dilation was not different between the groups. The HOMA(IR) was 2.5-fold higher in the sedentary group than in the endurance-trained group (P < .05). CONCLUSIONS: Sedentary individuals are characterized by reductions in both arterial compliance and insulin sensitivity relative to their endurance-trained peers, independent of changes in conventional risk factors for cardiovascular disease. These findings lend further support for the need for regular physical activity in the prevention of cardiovascular disease in individuals of all ages.