Mediation of the effect of serum uric acid on the risk of developing hypertension: a population-based cohort study

BackgroundSerum uric acid (SUA) had been associated with incident hypertension, but it is uncertain whether and to what extent the effect of SUA is mediated by other metabolic factors.MethodsData from the China Health and Retirement Longitudinal Study (CHARLS) during 2011 to 2015 was employed for this study. A total of 7639 participants aged between 35 and 96years without hypertension was included. Cox proportional hazards model was used to investigate the association between elevated SUA and hypertension. A mediation model was used to separately explore mediating effects (MEs) of metabolic factors on the association between SUA and incident hypertension.ResultsDuring a median 4.0years of follow-up, 2348 individuals were diagnosed with hypertension. After adjustment for metabolic confounders, participants with the highest SUA quartile had a hazard ratio of 1.16 (1.02-1.33) compared with the lowest category for incident hypertension. The association between SUA and incident hypertension were partially mediated by waist circumference (WC; ME=0.034), body mass index (BMI; ME=0.016), triglycerides (TG; ME=0.024), total cholesterol (TC; ME=0.009), high density lipoprotein cholesterol (HDL-C; ME=0.009), fasting plasma glucose (FPG; ME=0.005), and glycated hemoglobin (HbA1c; ME=-0.002). Additionally, proportional mediation was 32.7% by WC and 15.4% by BMI for obesity indicators; 23.1% by TG, 8.7% by TC, and 8.7% by HDL-C for blood lipid; and 4.8% by FPG and -1.9% by HbA1c for blood glucose.ConclusionsThe positive association between elevated SUA concentration and hypertension was reconfirmed in a Chinese population. Obesity indicators, blood lipids, and blood glucose may play important mediating roles in the pathways.