Prognostic Significance of 1-Year Serum Albumin Levels Within the Normal Range After Kidney Transplantation

Hypoalbuminemia is associated with poor outcomes in kidney transplantation (KT). However, what level is optimal in serum albumin is not clear for the long-term prognosis. To determine whether the long-term outcomes are different even between the normal ranges of serum albumin after KT, we analyzed data from 404 renal allograft recipients whose 1-year post-transplant serum albumin levels were within the normal limits (3.5-5.5g/dL). During a follow-up of 122 +/- 56 months, 97 graft losses, 20 patient deaths, and 50 cardiovascular (CV) events occurred. Based on 1-year serum albumin levels, the patients were divided into high normal (4.6g/dL, n=209) and low normal (<4.6g/dL, n=195) groups. Kaplan-Meier analyses revealed that the low normal group had poorer allograft survival (P=0.01), patient survival (P<0.001), and CV event-free survival (P<0.001) than the high normal group. Cox regression analysis confirmed that 1-year serum albumin was inversely associated with the risk of graft loss (hazard ratio [HR] 0.414, 95% confidence interval [CI] 0.200-0.856), patient death (HR 0.097, 95% CI 0.019-0.484), and CV events (HR 0.228, 95% CI 0.074-0.702). In conclusion, a relatively low 1-year post-transplant serum albumin level within the normal limits (<4.6g/dL) significantly predicts poor long-term outcomes.