RESUMO
Habitual physical activity has beneficial effects on cardiovascular risk reduction by improving vascular function but the underlying mechanism is still unclear. To address this issue, we performed a cross-sectional study comparing 50 physically active (PA) adults with 50 sedentary controls matched for age, sex, and cardiovascular risk factors. PA subjects had significantly higher flow-mediated dilation (FMD) than controls and higher serum levels of nitrite/nitrate, a marker of nitric oxide generation. In addition, PA subjects showed lower levels of urinary isoprostanes, a marker of reactive oxygen species (ROS) production, and lower serum levels of sNox2-dp, a validated assay to measure Nox2 activity, one of the most important enzymes producing ROS in the blood cells. FMD was independently correlated with sNox2-dp, after adjusting for possible confounding factors. Our observation leads to the hypothesis that, in adults, regular exercise preserves artery dilation through Nox2 decreased activity. Antioxid. Redox Signal. 28, 1576-1581.