Higher daily protein intake was a protective factor for graft function of kidney transplant recipients in the early post-transplant period: a retrospective cohort study.

BACKGROUND: The use of immunosuppressants and glucocorticoids after transplantation will affect the recipients' metabolism and aggravate their malnutrition. Adequate daily protein intake in the early post-transplant period facilitates the rapid recovery of surgical wounds. This study aimed to explore the relationship between daily protein intake and graft function in the early post-transplant period, which may provide a basis for clinical nutritional management of kidney transplant recipients. METHODS: This is a retrospective observational study. 176 kidney transplant recipients who underwent kidney transplant in West China Hospital from December 2021 to June 2022 were included. 24-hour urine urea nitrogen data were collected at 1 month and 3 months post-transplant to calculate daily protein intake. These KTRs were further divided into two groups according to the recommended daily protein intake for KTRs by KDOQI Clinical Practice Guideline for Nutrition in CKD, namely High group (with DPI ≥ 1.4 g/kg·d, n = 66) and Low group (with DPI < 1.4 g/kg·d, n = 110). Laboratory data and post-transplant adverse events within 3 months were recorded. Linear regressions were used to analyze the relationship between DPI and early post-transplant recovery as well as graft function. RESULTS: Recipients were divided into High and Low protein intake groups according to their daily protein intake 3 months after transplantation. The estimated glomerular filtration rate measured at three months post-transplant was significantly greater in the High protein intake group compared to the Low protein intake group (67.32 mL/min per 1.73 m2 vs. 58.88 mL/min per 1.73 m2, p = 0.044). Supporting this result, multiple regression analysis revealed that higher protein intake early after transplantation was a significant protective factor for graft function (p = 0.014). CONCLUSIONS: In the early post-transplant period, increased daily protein intake was linked to improved kidney graft function, lipid metabolism, and hemoglobin levels. Higher protein intake during this early post-transplant phase independently contributed to protecting graft function after kidney transplantation. Long-term protein intake regimens should be customized based on kidney function evaluated one year after the transplantation. CLINICAL TRIAL REGISTRY NUMBER: ChiCTR2500099186. (Registration Date 2025.03.19) Clinical Trial Registry ( http://www.chictr.org.cn/ ).