Received January 21, 2008
Accepted on June 25, 2008

CLINICAL EPIDEMIOLOGY

Elevated Uric Acid Increases the Risk for Kidney Disease

Rudolf P. Obermayr ^*1, Christian Temml , Georg Gutjahr , Maarten Knechtelsdorfer ^*, Rainer Oberbauer ^||, and Renate Klauser-Braun ^*

*Third Medical Department, Division of Nephrology, Diabetes and Hypertension, Donauspital, Sozialmedizinisches Zentrum Ost der Stadt Wien, Department of Health Prevention (MA 15/2, Gesundheit und Soziales), and Institute of Medical Statistics, ||Medical University Vienna, Vienna, and Department of Nephrology, KH Elisabethinen, Linz, Austria

¹ To whom correspondence should be addressed. E-mail: rudolf.obermayr{at}gmail.com.

	Abstract

Recent epidemiologic studies suggest that uric acid predicts the development of new-onset kidney disease, but it is unclear whether uric acid is an independent risk factor. In this study, data from 21,475 healthy volunteers who were followed prospectively for a median of 7 yr were analyzed to examine the association between uric acid level and incident kidney disease (estimated GFR [eGFR] <60 ml/min per 1.73 m²). After adjustment for baseline eGFR, a slightly elevated uric acid level (7.0 to 8.9 mg/dl) was associated with a nearly doubled risk for incident kidney disease (odds ratio 1.74; 95% confidence interval 1.45 to 2.09), and an elevated uric acid (9.0 mg/dl) was associated with a tripled risk (odds ratio 3.12; 95% confidence interval 2.29 to 4.25). These increases in risk remained significant even after adjustment for baseline eGFR, gender, age, antihypertensive drugs, and components of the metabolic syndrome (waist circumference, HDL cholesterol, blood glucose, triglycerides, and BP). In a fully adjusted spline model, the risk for incident kidney disease increased roughly linearly with uric acid level to a level of approximately 6 to 7 mg/dl in women and 7 to 8 mg/dl in men; above these levels, the associated risk increased rapidly. In conclusion, elevated levels of uric acid independently increase the risk for new-onset kidney disease.