Basal Endothelial Nitric Oxide Release is Preserved in Overweight and Obese Adults

OBJECTIVE: Impaired basal nitric oxide release is associated with a number of cardiovascular disorders including hypertension, arterial spasm, and myocardial infarction. We determined whether basal endothelial nitric oxide release is reduced in otherwise healthy overweight and obese adult humans.RESEARCH METHODS AND PROCEDURES: Seventy sedentary adults were studied: 32 normal weight (BMI/m(2)), 24 overweight (BMI \u3e or = 25 \u3c 30 kg/m(2)), and 14 obese (BMI \u3e or = 30 kg/m(2)). Forearm blood flow (FBF) responses to intra-arterial infusions of N(g)-monomethyl-L-arginine (5 mg/min), a nitric oxide synthase inhibitor, were used as an index of basal nitric oxide release.RESULTS: N(g)-monomethyl-L-arginine elicited significant reductions in FBF in the normal weight (from 4.1 +/- 0.2 to 2.7 +/- 0.2 mL/100 mL tissue/min), overweight (4.1 +/- 0.1 to 2.8 +/- 0.2 mL/100 mL tissue/min), and obese (3.9 +/- 0.3 to 2.7 +/- 0.2 mL/100 mL tissue/min) subjects. Importantly, the magnitude of reduction in FBF (approximately 30%) was similar among the groups.DISCUSSION: These results indicate that the capacity of the endothelium to release nitric oxide under basal conditions is not compromised in overweight and obese adults