Microalbuminuria mediates the association between serum uric acid and elevation of blood pressure: a longitudinal analysis in the Gusu cohort.

Abstract

Although hyperuricemia, microalbuminuria, and hypertension are highly correlated, their temporal relationship is largely unknown. We aimed to examine whether microalbuminuria mediated the association between hyperuricemia and hypertension. Leveraging a longitudinal cohort including 1981 Chinese adults who had blood pressures, urinary albumin to creatinine ratio (UACR), and uric acid measured twice 4 years apart, we examined the temporal relationships among hyperuricemia, microalbuminuria, and hypertension by cross-lagged panel analysis followed by a causal mediation analysis to confirm the temporal consequence. Age, sex, education level, cigarette smoking, alcohol consumption, obesity, blood glucose, and lipids were adjusted. The cross-lagged panel analysis demonstrated that the relationship from baseline UACR to follow-up uric acid was significantly smaller than that from baseline uric acid to follow-up UACR (β: 0.010 vs. 0.054, P < 0.001). The relationships from baseline blood pressures to follow-up UACR were also significantly smaller than that from baseline UACR to follow-up blood pressures (β: 0.031 vs. 0.092, P < 0.001 for systolic and β: 0.015 vs. 0.096, P < 0.001 for diastolic). The causal mediation analysis found that UACR partially mediated the association of baseline uric acid with follow-up SBP (mediate proportion: 9.14%, 95% CI: 1.58-23.00%) and DBP (mediate proportion: 7.38%, 95% CI: 1.05-19.00%). Microalbuminuria may follow elevated uric acid and partially mediate its effect on future risk of hypertension in Chinese adults.