High Post-Kidney Transplant Serum Uric Acid Levels Are Associated with Detrimental Outcomes

Background: The potential effects of post-transplant serum uric acid (SUA) levels and outcomes pose a variety of risks among kidney transplant (KTR) recipients. The association between post-transplant SUA and major detrimental outcomes among KTRs remains uncertain. Methods: We evaluated all adult kidney transplant recipients (KTRs) transplanted between 1/1/2000 and 12/31/2019. Recipients were included if they had a functioning allograft without any cardiovascular events (CVE) before their earliest SUA measurement within 5-13 months post-transplant. Survival analyses were performed regarding CVEs, CVE-related mortality, death-censored graft failure (DCGF), and uncensored graft failure, within 10 years after transplantation. Results: A total of 3808 eligible KTRs were followed for a median of 7.5 years after transplantation. Recipients with post-transplant SUA > 6.8 mg/dl had significantly higher risk of congestive heart failure (CHF) than those with SUA <6 mg/dl (adjusted hazard ratio [aHR] = 1.55, 95% CI: 1.10-2.19; p = 0.01); uncensored graft failure (aHR = 1.18, 95% CI: 1.02-1.36; p = 0.03), and DCGF (aHR = 1.28, 95% CI: 1.01-1.61; p = 0.04), after adjustment for multiple variables, including kidney graft function. No statistically significant association was found between SUA levels and other CVEs. There was no statistically significant risk for other outcomes of interest when comparing SUA < 6 mg/dl versus 6-6.8 mg/dl. Conclusions: Elevated early post-transplant SUA levels were associated with detrimental post-transplant outcomes, leading to increased morbidity and mortality through CHF, graft failure, and overall death.