High levels of uric acid correlate with decline of glomerular filtration rate in chronic kidney disease.

BACKGROUND: Clinical studies have suggested that high levels of uric acid may contribute to the development of hypertension and kidney disease. However the relation between uric acid and chronic kidney disease (CKD) has been inconsistent.

OBJECTIVE: To examine the association between plasma concentration of uric acid, and estimated glomerular filtration rate (GFR) in CKD subjects.

MATERIAL AND METHOD: In a cross-sectional study, authors surveyed 5,558 subjects, but only 750 CKD subjects in whom GFR was between 15 and 60 ml/min/1.73 m2 were included in the study. The GFR values were calculated by Cockcroft-Gault formula.

RESULTS: There were 65.5% males, mean age of 50.29 +/- 6.39 years and body mass index (BMI) of 21.68 +/- 2.64 kg/m2. The mean value of estimated GFR was 53.86 +/- 6.29 ml/min/1.73 m2. In subjects with serum uric acid fourth quartile displayed significantly higher BMI, higher systolic blood pressure (BP), higher diastolic BP, higher BUN, and higher serum creatinine, and lower estimated GFR as compared with the three lower quartiles. The correlation analysis showed that estimated GFR was negatively correlated with serum uric acid (r = -0.208, p < 0.01), age (r = -0.171, p < 0.01), systolic BP (r = -0.148, p < 0.01) and BMI (r = -0.147, p < 0.01). Multiple regression analysis, the presence of high serum uric acid levels were independently associated with a decline of GFR.

CONCLUSION: In CKD subjects, high levels of uric acid were independent associated with GFR decline. Our finding suggests that early detection and prevention on hyperuricemia in CKD subjects are critical.