The aim of this study was to assess changes in the estimated glomerular filtration rate (eGFR) in gouty patients with chronic kidney disease (CKD) using a "treat-to-target" (T2T) approach in gout. This multicenter observational retrospective study included patients diagnosed with gout and CKD stage 3 taking xanthine oxidase inhibitors (XOIs) (allopurinol or febuxostat) for at least 12 months. All patients were treated using a T2T strategy according to national gout guidelines to achieve the target levels of serum uric acid (sUA; < 5-6 mg/dl) within 6 months of the first visit. The primary outcome was to assess changes in eGFR. The effects of independent variables were analyzed over eGFR in a linear mixed-effects (LME) model. Fifty patients with gout and CKD stage 3 treated with XOIs with a T2T strategy for 12 months were included. Eighty-two percent of the patients achieved the sUA target during the study period. The improvement seen in eGFR was higher during the first 6 months, showing a median increase of 7.54 ml/min/m2 (SE = 1.25) and trending towards stability over 12 months. For every 1 mg/dl of decrease in sUA, an improvement of 1.5 ml/min/m2 in eGFR was observed (coefficient ± SE: - 1.58 ± 0.26) (p < 0.001) with no differences between type and dosage of XOIs treatment, colchicine administration, age, sex, and smoking status. A reduction in sUA levels using a T2T approach with XOIs at an optimal dose is possible and could help conserve and improve renal function in gouty patients with CKD stage 3.
Keywords: Chronic; Gout; Renal insufficiency; Renoprotective; Treat-to-target; Xanthine oxidase antagonists; Xanthine oxidase inhibitors.