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 +/- 0.7 kg/m(2); waist circumference (WC): 84.9 +/- 2.0 cm); 20 overweight/obese with WC < 102 cm (29.2 +/- 0.3 kg/m(2); 98.1 +/- 0.7 cm); and 20 overweight/obese with WC >= 102 cm (30.0 +/- 0.4 kg/m(2); 106.7 +/- 1.0 cm). 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 (similar to 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 +/- 1.3 ml/100 ml tissue/min) and without (4.5 +/- 0.3-11.6 +/- 0.8 ml/100 ml tissue/min) abdominal adiposity. Similarly, endothelial t-PA release to BK was lower (similar to 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 +/- 6.2 ng/100 ml tissue/min) and without (-0.3 +/- 0.6-48 +/- 7.5 ng/100 ml 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.