Serum uric acid and endothelial dysfunction in continuous ambulatory peritoneal dialysis patients

Endothelial dysfunction is an early predictor of cardiovascular events. Hyperuricemia has been shown to be associated with increased cardiovascular mortality. It remains unclear if serum uric acid (UA) is associated with endothelial dysfunction in peritoneal dialysis patients.

In this cross-sectional study, the relationship of UA and endothelial dysfunction was investigated in 189 stable peritoneal dialysis patients. The clinical and laboratory data were collected. Endothelial function was estimated by flow-mediated dilatation (FMD) of the brachial artery and expressed as percentage change relative to baseline diameter.

UA levels did not differ between 93 male and 96 female patients (416.31 +/- 86.93 vs. 395.52 +/- 87.47 mumol/l, p > 0.05). Patients were grouped into three tertiles on the basis of their serum UA levels. Systolic blood pressure (p = 0.007), serum phosphate (p = 0.005), high-sensitive C-reactive protein (hs-CRP) (p < 0.001), and FMD (p = 0.016) were all different among UA tertiles. FMD was found to be related with UA (p = 0.002) and hs-CRP (p = 0.006) in a Pearson's correlation analysis. Multivariate regression analysis showed that only UA was an independent determinant of FMD (beta = -0.237, p = 0.036).

There was an independent correlation between UA and FMD, and a higher UA level was related to worse endothelial function which may contribute to hypertension and cardiovascular morbidity.