Hyperuricemia as a risk factor for contrast-induced nephropathy in patients with chronic kidney disease

Objectives: Hyperuricemia as a risk factor for contrast-induced nephropathy (CIN) has not been studied. Background: The aim of the present study was to assess the influence of hyperuricemia on the development of CIN in patients undergoing coronary angiography. Methods: This was a prospective cohort study. A total of 266 patients with a mean age of 58.33 +/- 7.85 years and serum creatinine >= 1.2 mg/dl were divided into two groups (hyperuricemic, n = 126, and normouricemic, n = 140). CIN was defined as an increase of >= 25% in creatinine over baseline within 48 hr of angiography, and hyperuricemia as serum uric acid >= 7 mg/dl in males and >= 6.5 mg/dl in females. Results: CIN occurred in 15.1% of the hyperuricemic group and 2.9% of the normouricemic group (P < 0.001). Serum creatinine increased from 1.45 +/- 0.20 to 1.67 +/- 0.45 mg/dl in the hyperuricemic group and from 1.42 +/- 0.16 to 1.56 +/- 0.23 mg/dl in the normouricemic group (P < 0.001). Hyperuricemia [odds ratio (OR) 4.71; 95% confidence interval (95% CI) 1.29-17.21; P = 0.019] and a high incidence of multi-vessel coronary involvement (OR 3.59; 95% Cl 1.12-11.48; P = 0.032) in the hyperuricemic group were predictors of CIN. Hypoalbuminemia (P = 0.001) and age >= 70 years (P = 0.023) were other risk indicators of CIN. Length of hospital stay (P < 0.001) and CIN requiring renal replacement therapy (P = 0.017) were significantly higher in hyperuricemic group. Serum uric acid level >= 7 mg/dl in males and >= 5.9 mg/dl in females were found to be the best cut-off value for prediction of CIN. Conclusion: Our data support the hypothesis that patients with hyperuricemia are at risk of developing CIN. (c) 2006 Wiley-Liss, Inc.