Admission hyperuricemia increases the risk of acute kidney injury in hospitalized patients*

Wisit Cheungpasitporn, Charat Thongprayoon, Andrew M. Harrison, Stephen B. Erickson

The association between elevated admission serum uric acid (SUA) and risk of in-hospital acute kidney injury (AKI) is limited. The aim of this study was to assess the risk of developing AKI in all hospitalized patients with various admission SUA levels. This is a single-center retrospective study conducted at a tertiary referral hospital. All hospitalized adult patients who had admission SUA available from January 2011 through December 2013 were analyzed in this study. Admission SUA was categorized based on its distribution into six groups (<3.4, 3.4-4.5, 4.5-5.8, 5.8-7.6, 7.6-9.4 and >9.4 mg/dL). The primary outcome was in-hospital AKI occurring after hospital admission. Logistic regression analysis was performed to obtain the odds ratio (OR) of AKI of various admission SUA levels using the most common SUA level range (5.8-7.6 mg/dL) as the reference group. Of 1435 patients enrolled, AKI occurred in 263 patients (18%). The incidence of AKI and need for dialysis was increased in patients with higher admission SUA levels. After adjusting for potential confounders, SUA >9.4 mg/dL was associated with an increased risk of developing AKI, with ORs of 1.79 [95% confidence interval (CI) 1.13-2.82]. Conversely, admission SUA <3.4 and 3.4-4.5 mg/dL were associated with a decreased risk of developing AKI, with ORs of 0.38 (95% CI 0.17-0.75) and 0.50 (95% CI 0.28-0.87), respectively. Elevated admission SUA was associated with an increased risk for in-hospital AKI.