Aims — Elevated uric acid (UA) is common in diabetes and is implicated in the pathogenesis of chronic kidney disease (CKD). Lowering UA with allopurinol may delay CKD progression. We assessed the association between allopurinol and renal outcomes in older adults with and without diabetes, and whether this differed by diabetes status.
Methods — We conducted a population-based, retrospective cohort study of older adults ≥ 66 years old with a gout flare using administrative data in Ontario, Canada. The primary outcome was doubling of creatinine orkidney failure. Secondary outcomes were a composite of death or kidney failure, decline in estimated glomerular filtration rate >30%, and death and kidney failure individually. New allopurinol users were compared to non-users using Cox proportional hazards models and inverse probability of treatment weighting (IPTW). An interaction between allopurinol use and presence or absence of diabetes was assessed.
Results — In 5937 older adults with a gout flare (1911 with diabetes), 1304 (22%) were newly treated with allopurinol. Median follow-up time was 1.11 years [IQR 0.33-3.21] for allopurinol users and 3.38 [1.42-4.43] for non-users. There was no association between allopurinol use and the primary outcome (IPTW-adjusted HR 0.97, 95% CI 0.72-1.31), and this did not differ by diabetes status. Allopurinol use was not associated with any of the secondary outcomes.
Conclusions — Allopurinol use was not associated with renal outcomes in older adults with or without diabetes. This supports the interpretation of UA as a biomarker of CKD risk rather than a modifiable target for prevention or treatment of CKD.