A J-Shaped Association Between Serum Uric Acid Level and Allograft Outcomes After Living Donor Kidney Transplantation

Abstract

Hyperuricemia following kidney transplantation (KT) may contribute to a decline in allograft renal function, but be affected by KT-related confounding factors. Some studies have even suggested that a reduction in serum uric acid (UA) is associated with poor patient outcomes. Thus, we retrospectively analyzed the impact of serum UA on allograft outcomes in 281 KT recipients. KT recipients were divided into five groups according to serum UA level (mg/dL): Group I (n = 46), ≤ 5; Group II (n = 62), >5 and ≤6; Group III (n = 70), >6 and ≤7; Group IV (n = 53), >7 and ≤8; Group V (n = 50), >8. Regression analysis showed that serum UA level was significantly associated with future allograft function. In a Kaplan–Meier analysis, the dialysis-free survival of Group II recipients was better than that of the other groups (Group I, 140 ± 5 months; Group II, 208 ± 7 months; Group III, 148 ± 4 months; Group IV, 185 ± 12 months; Group V, 164 ± 11 months; P = 0.0164). In Cox proportional hazard models adjusting for estimated glomerular filtration rate, the relative risk of allograft loss still tended to be elevated in Group I (HR=3.417, 95% CI 1.138–10.258) and Group V (HR=2.793, 95% CI 1.108–7.041), using Group II as the reference. Our results suggest that there is a J-shaped association between serum UA levels and allograft outcomes in living donor KT recipients.