Endothelial dysfunction is an independent risk factor for cardiovascular events. Inflammatory mediators released by the adipose tissue can lead to local insulin resistance and endothelial dysfunction. This study addressed the relationship of adipocytokines with endothelial function and blood pressure.

In 92 newly diagnosed, drug-naïve essential hypertensive patients (HT) without organ damage and 66 normotensive subjects (NT), by an automated system, we measured endothelium-dependent and -independent vasodilation as brachial artery flow mediated dilation (FMD) before and after administration of glyceryl-trinitrate (GTN). Retinol binding protein-4 (RBP4) and resistin levels were determined by ELISA and RIA, respectively. Oxidative stress was evaluated by measuring serum malondyaldeide (MDA).

FMD was significantly (p=0.03) lower in HT (5.3±2.6%) than NT (6.1±3.1%), while response to GTN (7.5±3.7% vs 7.9±3.4%) was similar. RBP4 (60.6±25.1 vs 61.3±25.9 μg/ml), resistin (18.8±5.3 vs 19.9±6.1 ng/ml) and MDA levels (2.39±1.26 vs 2.08±1.17 nmol/ml) were not different in HT and NT.

RBP4 (r=−0.25; p=0.04) and resistin levels (r=−0.29; p=0.03) were related to FMD in NT, but not in HT (r=−0.03 and r=−0.10, respectively). In NT multivariate analysis, including RBP4 and confounders showed that only body mass index (BMI) or waist circumference remained related to FMD. In the multivariate model including resistin and confounders, BMI, age and resistin were significantly related to FMD, while only age remained a significant correlate of FMD when BMI was replaced by waist circumference.

In conclusion, adipocytokine levels, particularly resistin, are independent predictors of endothelial dysfunction in the peripheral circulation of healthy subjects, providing a pathophysiological link between inflammation from adipose tissue and early vascular alterations.