Cutaneous microvascular endothelium‐dependent vasodilation is impaired in young obese subjects (678.4)

Abstract

Cutaneous microvascular endothelium dependent vasodilation is impaired in young obese subjects Jordan C. Patik, Kevin M. Christmas, and R. Matthew Brothers Environmental and Autonomic Physiology Laboratory, Department of Kinesiology and Health Education, University of Texas at Austin Microvascular dysfunction is a precursor to a variety of cardiovascular diseases and contributes to insulin resistance and type II diabetes. Obese individuals are at a greater risk for the development of these aforementioned conditions relative to their lean counterparts. The purpose of this study was to asses endothelium dependent microvascular function in young, otherwise healthy, obese individuals. Specifically, we tested the hypothesis that the cutaneous microvascular response to intradermal administration of methacholine (MCh) would be blunted in obese relative to lean individuals. 6 young obese and 5 young lean individuals (Age: 24±2.2 vs. 25±1.18 years P>0.05; BMI: 34.96±1.89 vs. 22.24±0.84 kg/m2, P<0.001) participated in this study. Microvascular function was assessed using laser Doppler flowmetry to calculate cutaneous vascular conductance over a range of MCh concentrations infused through microdialysis membranes. Dose response curves were constructed to determine the effective concentration that elicits 50% of maximal conductance (EC50). Young obese subjects had significantly blunted EC50 responses to MCh infusion relative to the lean individuals (Obese: ‐3.173±0.526 vs. Lean: ‐4.875 ±0.199 log molar concentration of MCh, P = 0.02). Our preliminary results support the hypothesis that impaired endothelium dependent vasodilation is present in relatively young obese individuals prior to the development of obesity related disease.