Vargas-Santos AB, et al. - In this population-based UK cohort study, researchers evaluated the association of allopurinol use in gout with the risk of developing chronic kidney disease (CKD) stage ≥ 3. They found that the initiation of allopurinol of ≥ 300 mg/d had a lower risk of renal function deterioration. Medical practitioners were, therefore, cautioned to consider evaluating other possible causes when patients with gout experience renal function decline since allopurinol did not seem to be related to renal function decline.

Methods

• A time-stratified, propensity score-matched, population-based, prospective cohort study involving people with newly diagnosed gout who initiated allopurinol (≥ 300 mg/d) vs those who did not initiate allopurinol was conducted using the Health Improvement Network (THIN), a UK general practitioner electronic health records database.
• Using Cox proportional hazards regression, the data were analyzed.
• They propensity score matched 4,760 initiators of allopurinol (≥ 300 mg/d) to the same number of non-initiators of allopurinol, excluding those with CKD stage ≥ 3 or urate-lowering therapy use prior to diagnosis of gout among adults aged 18-89 years with newly diagnosed gout.
• Development of CKD stage ≥ 3 was the main outcome and measure included.

Results

• Of the 4,760 allopurinol initiators and same number of non-initiators, 579 and 623, respectively, developed stage ≥ 3 CKD with a mean follow-up time of 5 and 4 years, mean age of 57 years, and mean body mass index of 30 for both groups.
• Use of allopurinol of ≥ 300 mg/d was related to lower risk of developing CKD stage ≥ 3 vs nonusers, with an HR of 0.87 (95% CI: 0.77-0.97).
• No association was noted between allopurinol initiation at < 300 mg/d and renal function decline (HR: 1.00; 95% CI: 0.91-1.09).