Association Between Endothelial Function (Assessed on Reactive Hyperemia Peripheral Arterial Tonometry) and Obstructive Sleep Apnea, Visceral Fat Accumulation, and Serum Adiponectin

Abstract

Background:Visceral obesity, low adiponectin, and severe obstructive sleep apnea (OSA) are associated with cardiovascular diseases, but the interactions among these factors on endothelial dysfunction are not well known.Methods and Results:Endothelial function in 133 patients after polysomnography was evaluated as reactive hyperemia index (RHI) on reactive hyperemia peripheral arterial tonometry. Visceral obesity was defined as visceral fat area ≥100 cm²on computed tomography. RHI was significantly correlated with apnea hypopnea index (AHI), visceral fat area, and serum adiponectin (r=–0.24, P=0.0055, r=–0.19, P=0.031, and r=0.20, P=0.019, respectively). RHI in patients with visceral obesity was significantly decreased in the presence of severe OSA (AHI ≥30; P=0.042). On multivariate regression analysis, only severe OSA remained as an independent predictive factor of RHI (P=0.024, R²=5.4%). RHI in patients with severe OSA (n=44) was significantly improved after 3 months of continuous positive airway pressure (CPAP) treatment (1.78±0.40 before CPAP vs. 2.00±0.53 after CPAP, P=0.013), similarly to those with AHI <30 (P=0.45).Conclusions:Severe OSA, but not visceral fat area or serum adiponectin, was independently associated with endothelial function according to RHI. In addition, impaired endothelial function was reversible following 3 months of CPAP treatment. (Circ J 2015; 79: 1381–1389)