A JEYARUBAN1,2,3, WE HOY1,2, A CAMERON1,2, HG HEALY1,2,3, J ZHANG1,2, AJ MALLETT1,2,3
1CKD.QLD and NHMRC CKD.CRE, Brisbane, Australia, 2Faculty of Medicine, The University of Queensland, Herston, Australia, 3Kidney Health Service, Royal Brisbane and Women’s Hospital, Herston, Australia
Aim: To investigate the possible associations of hyperuricaemia, gout and allopurinol on changes in renal function amongst patients with chronic kidney disease (CKD).
Background: There is increasing evidence for an association between hyperuricaemia and incident CKD. However, data regarding the role of hyperuricaemia, gout and allopurinol treatment on the rate of progression of CKD is scant.
Methods: A retrospective cohort study of 1,123 RBWH patients enrolled in the CKD.QLD registry from January 2011 to August 2017 (minimum of 2years follow-up). Patients were divided into two uric acid categories (cut off 0.36mmol/L). Associations of delta eGFR(CKD-EPI) with gout, allopurinol treatment and hyperuricaemia were analysed.
Results: Patients with an entry urate >0.36mmol/L were older (68vs 64years; p<0.05), had higher BMI (31.3kg/m²vs 29.5kg/m²; p<0.05), worse baseline kidney function (eGFR: 37.7mL/min/1.73m²vs 52mL/min/1.73m²; p<0.05) and higher proportion of diabetes (50%vs 37%; p<0.05), ischaemic heart disease (32%vs 21%; p<0.05), heart failure (9%vs; 5%; p=0.9), cerebrovascular disease (12%vs 6%; p<0.05), and peripheral vascular disease (15%vs 10%; p=0.09). Proportion of patients with gout, hyperuricaemia and allopurinol treatment increased with advanced CKD stages.
Prescription of allopurinol did not have a significant association with delta eGFR in patients with hyperuricaemia (1.8mL/min/1.73m²/year vs 1.6mL/min/1.73 m²/year; p=0.2) or gout (2.2mL/min/1.73m²/year vs 1.8 mL/min/1.73m²/year; p=0.5). Age-adjusted analysis exploring the impact of urate, gout and allopurinol treatment showed no significant association with delta eGFR. Furthermore, age-adjusted analysis revealed a significant association between urate level >0.36mmol/L and progression to renal replacement therapy (RRT, p<0.05), however neither gout nor allopurinol had a significant association.
Conclusion: Gout and allopurinol treatment did not appear to be independently associated with deterioration of renal function. However, hyperuricaemia appears to be associated with progression to RRT.
Andrew Jeyaruban is currently a medical registrar with a keen interest in renal medicine. He graduated from James Cook University with Honours in 2014. Andrew then completed his residency at the Royal Brisbane and Women’s Hospital Brisbane, Australia. He is currently a basic physician trainee at the Liverpool Hospital, Sydney.