Prognostic Nutritional Index Trajectories Predict Kidney Function in Kidney Transplant Recipients: A Latent Class Growth Model Study

BACKGROUND Nutritional status can be an important, dynamic determinant of clinical outcomes in kidney transplant recipients. This study investigated the trajectory and potential classes of the prognostic nutritional index (PNI) in kidney transplant recipients using a latent class growth model (LCGM), and assessed their predictive role in renal allograft function. MATERIAL AND METHODS This retrospective study included 257 kidney transplant recipients who received treatment in a tertiary hospital in Anhui Province from January 2019 to November 2020. Their data were collected at each 4 timepoints: T0 (pre-surgery, using the results of the recipient's most recent laboratory test prior to transplant), T1, T2, and T3 (1, 6, and 12 months, respectively after transplant surgery). The LCGM was conducted using Mplus 8.4, and a multiple linear regression model was employed to examine the ability of PNI trajectory to predict renal allograft function. RESULTS Using LCGM, 2 classes of PNI patterns best fit the sample: the low PNI slow growth group (C1, n=122,47.5%) and the high PNI fast growth group (C2, n=135, 52.5%). The linear regression showed that being a woman and being in the high PNI fast growth group were negative predictors of a high creatinine level (B=-35.946, P<0.001; B=-15.147, P=0.023). CONCLUSIONS There were 2 trajectories of PNI in the sample, with lower creatinine values 1 year after transplantation in the high PNI fast growth class. The initial level and developmental rate of PNI can positively predict renal allograft function. PNI may serve as a prognostic marker for renal allograft function in kidney transplant recipients.