Zhongguo quanke yixue (Nov 2023)
Association between Serum Uric Acid Level and the Risk of Chronic Kidney Disease among the Elderly in Longevity Areas of China
Abstract
Background Hyperuricemia (HUA) caused by elevated serum uric acid (SUA) has been shown to be an independent risk factor for the development and progression of chronic kidney disease (CKD). However, there are few cohort studies on the correlation of SUA level with the development and progression of CKD in the elderly of China. Objective To explore the association of baseline SUA level and its changes with the risk of chronic kidney disease (CKD) and estimated glomerular filtration rate (eGFR) in the elderly in longevity areas of China. Methods Based on the Healthy Aging and Biomarkers Cohort Study (HABCS), a sub cohort of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), the older adults who received physical examination and with biomedical indicators in 2012 and 2014 were selected as the study subjects from December 2021 to May 2022. The age, gender, blood pressure, blood lipids, blood glucose and other biomedical indicators were collected at baseline and follow-up period. Cox proportional hazards regression model was used to analyze the association of different SUA levels with the risk of CKD. Spearman rank correlation and generalized linear model analysis were used to analyze the association between baseline SUA level and baseline eGFR level and the linear correlation between changes in SUA level and eGFR changes in the elderly, respectively. Results A total of 981 subjects were included in the study, with the median age of 79 (70, 88) years, the prevalence of HUA of 6.8% (67/981), the cumulative follow-up of 2 029 person-years and the median follow-up of 2.05 years, including 179 new cases of CKD, the cumulative incidence of CKD during the follow-up was 18.2%〔95%CI (15.9%, 20.8%) 〕, and the incidence density was 88.22/1 000 person-years〔95%CI (76.24/1 000 person-years, 101.41/1 000 person-years) 〕. Cox proportional hazards regression analysis with SUA quartile grouping as the independent variable showed that compared with the lowest quartile group of baseline SUA level (Q1), the HR value for the risk of CKD in the highest quartile group of baseline SUA level (Q4) was 2.08〔95%CI (1.27, 3.41), P=0.004〕. Cox proportional hazards regression analysis with SUA level as the independent variable showed that, for every 10 μmol/L increase in baseline SUA level, the risk of CKD in the elderly increased by 4% (P<0.001). Cox proportional hazards regression analysis with HUA as the independent variable showed an increased risk of CKD in elderly with HUA compared to those without HUA, with the HR value of 2.00〔95%CI (1.20, 3.24), P=0.007〕. The median baseline SUA was 270.60 (223.10, 325.90) μmol/L, the median baseline eGFR was 84.07 (73.08, 98.38) mL·min-1· (1.73 m2) -1 in the elderly. Spearman rank correlation analysis showed a negative correlation between the above two (rs=-0.363, P<0.001). The results of generalized linear model analysis showed that for every 10 μmol/L increase in baseline SUA level, the baseline eGFR decreased by 0.897 mL·min-1· (1.73 m2) -1 (P<0.001). The median change of SUA level was -3.55 (-40.60, 31.90) μmol/L and the median change of eGFR was 3.49 (-8.13, 15.89) mL·min-1· (1.73 m2) -1 in the elderly during the follow-up period of this study, and Spearman rank correlation analysis showed a negative correlation between the above two (rs=-0.355, P<0.001). The results of the generalized linear model analysis showed that for every 10 μmol/L increase in SUA level in the elderly during the follow-up period, eGFR decreased by 1.027 mL·min-1· (1.73 m2) -1 in the elderly (P<0.001) . Conclusion Elevated SUA level in the elderly is associated with an increased risk of CKD and a declined eGFR in China.
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