Objectives High serum uric acid (SUA) levels have been suggested to be associated with chronic kidney disease (CKD) risk factors, such as hypertension and diabetes. However, it is unclear whether SUA is independently associated with chronic renal insufficiency. We aimed to examine the relationship between SUA and developing chronic renal insufficiency in a general population in Beijing.
Methods The association between SUA and developing chronic renal insufficiency was examined among 1541 participants aged 35 to 64 years at baseline, as a part of Chinese Multi-provincial Cohort Study (CMCS), in a general population in Beijing. After 5 years follow-up, a total of 1255 subjects were reexamined, but 1316 subjects were included in this analysis. Participants completed a lifestyle and medical history questionnaire and had their blood pressure measured, and blood samples taken. Hyperuricemia was defined as the mean values of SUA ≥7 mg/dl in male and ≥6mg/dl in female. The glomerular filtration rate (GFR) values were calculated by the Modification of Diet in Renal Disease (MDRD) equation. Chronic renal insufficiency was defined as 60≤GFR<90 mL/min per 1.73 m2, and CKD was defined as GFR<60 mL/min per 1.73 m2. Multivariate binary logistic regression was used to determine the independent effect of SUA for chronic renal insufficiency and CKD.
Results The mean values of estimated GFR in participants with hyperuricemia and without hyperuricemia were 75.32 ± 12.80 and 73.28 ± 9.37 mL/min per 1.73 m2 respectively. The 5-year incidence of CKD and chronic renal insufficiency were 1.4% and 33.8% in this study population, 2.3% and 41.4% in male, 0.6% and 26.7% in female. That of chronic renal insufficiency in three age groups: 35 to 44 years old, 45 to 54 years old, and 55 to 64 years old were 22.5%, 36.3%, and 43.0% respectively (trend P <0.001). The adjusted hazard ratio (HR) for incident CKD and chronic renal insufficiency were 1.86 (95% confidence interval (CI), 1.17 to 2.95) and 1.25 (95%CI, 1.07 to 1.47) for baseline SUA level (increased by 1 mg/dL). Compared with the subjects with normal baseline and follow-up SUA levels, the multivariate-adjusted HR for incident chronic renal insufficiency of the subjects with normal baseline but abnormal follow-up SUA level was 1.68 (95%CI, 1.04 to 2.72).
Conclusions High serum uric acid level was independently associated with incidence of chronic renal insufficiency in a general population in Beijing. Maintaining normal SUA level should be attended as a strategy to prevent CKD outcome.