Impact of acute exercise on brachial artery flow-mediated dilatation in young healthy people

Eighty-six young healthy volunteers were prospectively enrolled from January 2011 to December 2011. The subjects completed FMD tests at rest and immediately after treadmill exercise test. Primary outcome was the impact of acute exercise on FMD, measured by the difference of FMD before and after exercise. Secondary outcomes were the relationship of gender and exercise habit with FMD.Seventy-four subjects who met the eligibility criteria were included for analysis. Thirty-five (47.3%) were male, and the mean age was 22.7±2.7 years. FMD was reduced after exercise (8.98±4.69 to 7.51±4.03%; P=0.017) and the reduction was found in female group (10.36±5.26 to 7.62±3.71%; P=0.002) but not in male group. Post-exercise FMD was significantly impaired in subjects who did not exercise regularly (6.92±3.13% versus 8.95±5.33%; P=0.003). The decrease of FMD after exercise was greater in female group (？2.75±5.28% versus 0.27±3.24%; P=0.003) and was associated with exercise habit (β=2.532; P=0.027).In healthy young subjects, FMD was reduced after a bout of acute exercise. The impact of acute exercise showed significant differences according to gender and exercise habit. FMD impairment after acute exercise was observed in females and subjects without regular exercise.Endothelial dysfunction is an important factor in the development of atherosclerosis, hypertension, and coronary artery disease (CAD) [1-4]. Impaired endothelial function is observed in subjects with risk factors for atherosclerosis and in patients with essential hypertension [2,5,6]. Also it is an important predictor of long-term cardiovascular events [7,8].There are several methods to assess endothelial dysfunction and flow-mediated dilatation (FMD) is the most widely used non-invasive method to assess the endothelial function, reflecting the endothelial nitric oxide (NO) dependent vasodilation in response to occlusion-induced reactive hyperemia [5,9]. As FMD is non-invasive and reliable, allows repeated measurements [1