Usefulness of visceral obesity (waist/hip ratio) in predicting vascular endothelial function in healthy overweight adults

Vascular endothelial dysfunction (VED) is associated with obesity; however, its etiology remains controversial. By determining the predictors of fasti ng and postprandial endothelial function in overweight adults without other cardiovascular risk factors, we were able to investigate novel mechanisms directly linking obesity to VIED. Thirty-two healthy adults (body mass inde x [BMI] greater than or equal to 27 kg/m(2)) underwent determination of fas ting low-density lipoprotein (LDL) particle size, high sensitivity C-reacti ve protein levels, anthropometric measurements, and endothelial function by flow-mediated dilation (FMD) of the brachial artery. Postprandial lipemia and FMD were measured 4 hours after ingestion of a high-fat meal. Blood pre ssures and fasting levels of lipoproteins, glucose, insulin, and fatty acid s were within normal limits in all subjects. An abdominal fat pattern, as d etermined by an increased waist/hip ratio (WHIZ), was the sole significant predictor of FMD (r = -0.58, p = 0.001), despite no significant correlation between whole body obesity (BMI) and FMD. At comparable levels of BMI, obe se subjects with a WHR greater than or equal to0.85 had a significantly blu nted FMD compared with those with a WHR <0.85 (3.93 +/- 2.85% vs 8.34 +/- 5 .47%, p = 0.016). Traditional coronary risk factors, C-reactive protein, po stprandial lipemia, and LDL particle size did not predict FMD. We found no appreciable alteration in the postprandial state from fasting FMD (6.31 +/- 4.62% vs 6.25 +/- 5.47%, p = 0.95). The same results were found when women were analyzed alone. Increased abdominal adiposity determined by a simple WHR is a strong independent predictor of VED even in healthy overweight adu lts; this is a finding unexplained by alterations in conventional risk fact ors, systemic inflammation, or the atherogenic lipoprotein pattern. (C) 200 1 by Excerpta Medica, Inc.