Selective ET-A receptor blockade with BQ-123 elicited a significant ~20% vasodilator response in overweight and obese adults but not in normal weight adults, demonstrating enhanced ET-1-mediated vasoconstriction.
Cross-Sectional (n=79)
No
Does increased ET-1-mediated vasoconstriction contribute to adiposity-related impairment in endothelium-dependent vasodilation in overweight and obese adults?
Overweight and obesity are associated with enhanced ET-1-mediated vasoconstriction, which contributes to endothelial vasodilator dysfunction.
p-value: p=0.041
Endothelin (ET)-1-mediated vasoconstrictor tone contributes to the development and progression of several adiposity-related conditions, including hypertension and atherosclerotic vascular disease. The aims of the present study were to determine 1) whether endogenous ET-1 vasoconstrictor activity is elevated in overweight and obese adults, and, if so, 2) whether increased ET-1-mediated vasoconstriction contributes to the adiposity-related impairment in endothelium-dependent vasodilation. Seventy-nine adults were studied: 34 normal weight body mass index (BMI) < 25 kg/m(2), 22 overweight (BMI ≥ 25 and < 30 kg/m(2)), and 23 obese (BMI ≥ 30 kg/m(2)). Forearm blood flow (FBF) responses to intra-arterial infusion of ET-1 (5 pmol/min for 20 min) and selective ET-1 receptor blockade (BQ-123, 100 nmol/min for 60 min) were determined. In a subset of the study population, FBF responses to ACh (4.0, 8.0, and 16.0 μg·100 ml tissue(-1)·min(-1)) were measured in the absence and presence of selective ET-1 receptor blockade. The vasoconstrictor response to ET-1 was significantly blunted in overweight and obese adults (∼ 70%) compared with normal weight adults. Selective ET-1 receptor blockade elicited a significant vasodilator response (∼ 20%) in overweight and obese adults but did not alter FBF in normal weight adults. Coinfusion of BQ-123 did not affect FBF responses to ACh in normal weight adults but resulted in an ∼ 20% increase (P < 0.05) in ACh-induced vasodilation in overweight and obese adults. These results demonstrate that overweight and obesity are associated with enhanced ET-1-mediated vasoconstriction that contributes to endothelial vasodilator dysfunction and may play a role in the increased prevalence of hypertension with increased adiposity.
Weil et al. (2011) conducted a cross-sectional in Overweight and Obesity (n=79). Intra-arterial infusion of ET-1 and BQ-123 (ET-A receptor antagonist) vs. Normal weight adults was evaluated on Forearm blood flow (FBF) response to selective ET-A receptor blockade (BQ-123) (p=0.041). Selective ET-A receptor blockade with BQ-123 elicited a significant ~20% vasodilator response in overweight and obese adults but not in normal weight adults, demonstrating enhanced ET-1-mediated vasoconstriction.