Influence of abdominal obesity on vascular endothelial function in overweight/obese adult men

It has been suggested that body fat distribution may be an important determinant of the impact of adiposity on endothelial function. We tested the hypothesis that overweight/obese adults with abdominal adiposity exhibit worse endothelial vasodilator and fibrinolytic function than overweight/obese adults without abdominal adiposity. Sixty adult men were studied: 20 normal weight (BMI: 22.3 0.7kg/m²; waist circumference (WC): 84.9±2.0cm); 20 overweight/obese with WC 102cm (29.2±0.3kg/m²; 98.1±0.7cm); and 20 overweight/obese with WC 102cm (30.0±0.4kg/ m²; 106.7±1.0cm). Forearm blood flow (FBF) responses to intra-arterial acetylcholine and sodium nitroprusside (SNP) were measured. Additionally, net endothelial release of tissue-type plasminogen activator (t-PA) was determined in response to bradykinin (BK) and SNP. Overweight/obese men demonstrated lower (∼30%; P<0.01) FBF responses to acetylcholine compared with normal weight controls. However, there were no differences in FBF responses to acetylcholine between overweight/obese men with (4.1±0.3-10.8±1.3ml/100ml tissue/min) and without (4.5±0.3-11.6±0.8ml/100ml tissue/min) abdominal adiposity. Similarly, endothelial t-PA release to BK was lower (∼40%; P<0.05) in the overweight/obese men compared with normal weight controls; however, t-PA release was not different between the overweight/obese men with (0.7±0.4-40.4 6.2ng/100ml tissue/min) and without (0.3 0.6-48 7.5ng/100ml tissue/min) abdominal adiposity. These results indicate that abdominal obesity is not associated with greater impairment in endothelial vasodilation and fibrinolytic capacity in overweight/obese men. Excess adiposity, regardless of anatomical distribution pattern, is associated with impaired endothelial function.