Serum Uric Acid As An Independent Risk Factor On Progression Of Chronic Kidney Disease In Gout Patients With Uric Acid Lowering Agent

Background Hyperuricemia is particularly common in patients with chronic kidney disease (CKD). Its role, however, as a risk factor for renal outcomes of CKD is debated and those data in gout patients with CKD are rare. Objectives This aim of study was to evaluate long-term effect of serum uric acid (SUA) level on progression of CKD in gout patients with uric acid lowering treatment. Methods All patients who had a first visit for gout with CKD at Samsung Medical Center between 1995 and 2003, and follow-up until December 2012 or expired during follow-up period were included and retrospective analyzed. CKD was defined as an estimated glomerular filtration rate GFR) of 2 via the Modification of Diet in Renal Disease Study equation more than 3 months according to the Kidney Disease Outcome Quality Initiative CKD classification. All serum creatinine and matched SUA taken during follow-up period were analyzed by using mixed effect model to determine the effect of SUA level on renal outcome. Results One-hundred eleven gout patients with CKD were observed. The mean age of the patients at diagnosis of gout was 51.3 and mean follow-up duration was 13 years. Baseline estimated GFR and serum creatinine were 47.7 mL/min/1.73m 2 and 1.62 mg/dL, respectively. Eight (7.2%) patients revealed CKD stage 4 and the rest of patients (92.8%) were CKD stage 3. Maintaining the SUA below 6 mg/dL showed protective effect on serum creatinine and estimated GFR compared with maintaining SUA more than 6 mg/dL ( p p =0.02, respectively). The elevation of SUA as a continuous variable was also related to poor renal outcome in gout patients with CKD ( p p p p =0.014, respectively). Conclusions Our long term follow-up data demonstrated the SUA level was independent risk factor for progression of CKD in gout patients with uric acid lowering treatment. Maintaining of SUA level below 6 mg/dL would be essential to protect renal function in gout patients with CKD. Disclosure of Interest None declared