Association of Serum Uric Acid with Arterial Stiffness in Peritoneal Dialysis Patients

BACKGROUND/AIMS: Serum uric acid (SUA) has been proposed as a mediator associated with increased cardiovascular risk and arterial stiffness. However, evidence on the association between SUA and arterial stiffness in peritoneal dialysis (PD) patients is lacking. The aim of this study was to examine the relationship between SUA and arterial stiffness in PD patients. METHODS: The patients who performed vascular profiler test from January 1, 2014 to October 31, 2016, and with SUA values were enrolled. Arterial stiffness was evaluated by brachial-ankle pulse wave velocity (baPWV). The relationship between SUA and baPWV was tested by multiple linear regression models. RESULTS: Of 645 PD patients, mean SUA was 6.80 (±1.29) mg/dL, mean baPWV was 1713 (±505) cm/s. In fully adjusted linear regression models, higher SUA was significantly associated with higher baPWV in young [standardized coefficients (β), 0.085; 95% confidence interval (95% CI), 0.013 to 0.130; P=0.02] but not in elderly (β, -0.194; 95% CI, -0.774 to 0.093; P=0.1) PD patients. In gender-stratified models of young patients, there was a significant association between SUA and baPWV in male (β, 0.115; 95% CI, 0.015 to 0.182; P=0.02) but not in female. Male in the highest gender-specific SUA quartile had a higher baPWV than those in the lowest quartile (β, 0.132; 95% CI, 0.011 to 0.209; P=0.03). This gender difference was reversed when selecting male patients with lower SUA levels (quartile 1 and 2) and female patients with higher SUA levels (quartile 3 and 4). CONCLUSION: SUA was positively associated with baPWV in young PD patients, and this association was significant in males but not in females, which is possibly explained by the higher SUA level in males than in females.