ASSOCIATION OF URIC ACID IN SERUM AND URINE WITH SUBCLINICAL RENAL DAMAGE: HANZHONG ADOLESCENT HYPERTENSION STUDY

Abstract

Objective: Uric acid (UA) has been proposed as an important risk factor for cardiovascular and renal morbidity. The aim of the study was to examine the associations of UA in blood and urine with subclinical renal damage (SRD) and its progression in a Chinese cohort. Design and method: In 1987, we established the Hanzhong Adolescent Hypertension Study cohort based on a baseline survey of 4623 adolescents aged 6–15 years in Hanzhong, Shaanxi, China. 1) 2342 participants from our previously established cohort who were followed up in 2017 were included. Cross-sectional analysis was used to examine the relationships between serum and urinary UA and the risk of SRD. 2) A total of 266 participants were recruited from the same cohort in 2013, and followed up in 2017. Longitudinal analysis was used to determine the relationships of serum and urinary UA with progression of SRD, which was defined as urinary albumin-to-creatinine ratio (uACR) progression or estimated glomerular filtration rate (eGFR) decline. Results: In cross-sectional analysis, uACR levels were positively correlated with serum UA (β = 0.093, P < 0.001), and urinary uric acid/creatinine ratio (uUA/Cre) (β = 0.042, P = 0.041). eGFR was negatively associated with serum UA (β = −0.300, P < 0.001) but positively associated with uUA/Cre levels (β = 0.086, P < 0.001) in all subjects. Furthermore, the multivariate-adjusted odds ratios for SRD compared with non-SRD were 3.574 (2.255–5.664) for uUA/Cre. We further assessed the effect of UA excretion on the risk of SRD when uUA/Cre was modelled in quartiles. After adjusting for multiple confounders, the ORs (95% CIs) of SRD across increasing quintiles of uUA/Cre were 1.00, 1.122 (0.756–1.664), 1.362 (0.928–1.998) and 2.480 (1.719–3.578) (P for trend < 0.001). In longitudinal analysis, 4-year changes in uUA/Cre (β = −0.114, P = 0.040) and serum UA (β = 0.187, P = 0.001) were significantly associated with eGFR decline. Conclusions: This study suggested that urinary UA excretion was significantly associated with the risk of SRD in Chinese adults. Furthermore, 4-year changes of serum and urinary UA were associated with SRD progression. These findings suggest that UA, especially urinary UA, may be used as a simple, noninvasive marker for early detection of decreased renal function in otherwise healthy subjects.