Open AccessAssociation between post-transplant serum uric acid levels and kidney transplantation outcomes
Author(s) -
Deok Gie Kim,
Hoon Young Choi,
Ha Yan Kim,
Eun Ju Lee,
Kyu Ha Huh,
Myoung Soo Kim,
Chung Mo Nam,
Beom Seok Kim,
Yu Seun Kim
Publication year - 2018
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0209156
Subject(s) - medicine , hazard ratio , dialysis , kidney transplantation , transplantation , proportional hazards model , renal function , retrospective cohort study , confounding , confidence interval , gastroenterology , cohort , hyperuricemia , kidney disease , population , uric acid , cohort study , surgery , environmental health
Background Serum uric acid (UA) level has been reported to be associated with chronic allograft nephropathy and graft failure in patients who undergo kidney transplantation (KT). However, the role of serum UA level in renal graft survival remains controversial. Objective This study aimed to investigate the effect of mean serum UA level during two different post-KT periods on long-term renal graft outcomes in a large population cohort in which living donor KT prevails. Material and methods A retrospective cohort study was performed using KT data prospectively collected at a single institution. Patients (n = 2,993) were divided into low-, normal-, and high-UA groups according to the mean serum UA level within the first year (1-YR) and 1–5 years (5-YR) after transplantation. Results In the 1-YR Cox proportional hazards analysis, the low- and high-UA groups had a significantly decreased and increased risk, respectively, for overall graft failure (OGF), death-censored graft failure (DCGF), and composite event (return to dialysis, retransplantation, death from graft dysfunction, and 40% decline in estimated glomerular filtration rate) compared with the normal-UA group. Similarly, in the 5-YR analysis, the low-UA group had a significantly reduced risk of DCGF compared with the normal-UA group, whereas the high-UA group had a significantly increased risk of all three graft outcomes. In a marginal structural model, hyperuricemia had a significant causal effect on worsening graft outcomes, with consideration of all confounding variables (OGF: hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.33–3.78; DCGF: HR 2.38, 95% CI 1.09–4.9; composite event: HR 3.05, 95% CI 1.64–5.49). Conclusions A low-to-normal serum UA level within the first year and 1–5 years after KT is an independent factor for better renal allograft outcomes in the long-term follow-up period rather than high serum UA level.