Uric acid has a J-shaped association with cardiovascular and all-cause mortality in kidney transplant recipients

Abstract

The association between serum uric acid and kidney graft and recipient survival is uncertain. During 2000-2011, we measured serum uric acid at week 10 after transplantation. Of 2748 transplanted patients, 2200 (80.1%) attended this visit. After a median follow-up of 7.4 yr, 378 patients had died, 143 from a cardiovascular cause, and 185 patients lost their graft. The third quintile of uric acid levels (357-405 μM) had the lowest mortality risk and was used as reference group. In Cox proportional hazard models adjusting for graft and patient characteristics, the fifth quintile of uric acid levels (>474 μM) was independently associated with cardiovascular mortality (hazard ratio [HR] = 2.87 [1.55-5.32], p = 0.001) and all-cause mortality (HR = 1.57 [1.09-2.25], p = 0.02). Also, the lowest quintile of uric acid levels (<309 μM) showed a trend toward increased risk of cardiovascular mortality (HR = 1.79 [0.90-3.58], p = 0.10) and all-cause mortality (HR = 1.31 [0.89-1.93], p = 0.18). The increased risk at low uric acid levels was confined to diabetic recipients. Uric acid was not associated with death-censored graft loss. In conclusion, uric acid has a J-shaped association with cardiovascular and all-cause mortality in kidney transplant recipients.

Keywords: kidney transplant recipients; mortality; uric acid.