Early Post-Transplant Changes in Nutritional Status Predict Long-Term Graft Loss and Mortality

Background: Nutritional status is an important determinant of outcomes after kidney transplantation, yet the prognostic significance of longitudinal changes in nutritional indices remains insufficiently investigated. We evaluated whether first-year changes in the Prognostic Nutritional Index (PNI) and Controlling Nutritional Status (CONUT) score were associated with long-term adverse outcomes in kidney transplant recipients (KTRs). Methods: This retrospective cohort study included 352 adult KTRs with a median follow-up of 11.4 years. PNI and CONUT were calculated before transplantation and at the first post-transplant year. Patients were categorized according to changes in nutritional status as improved/stable or worsened. The primary outcome was a composite of end-stage renal disease (ESRD) or death with a functioning graft. Two separate multivariable logistic regression models were constructed to evaluate the associations of changes in first-year PNI and CONUT with the composite outcome after adjustment for clinically relevant demographic and transplant-specific variables, including first-year rejection episodes, estimated glomerular filtration rate (eGFR), and urine protein-to-creatinine ratio (PCR). Additional analyses were performed separately for graft loss and death with a functioning graft. Results: Baseline PNI and CONUT scores were comparable between patients with and without adverse outcomes. Patients who reached the composite outcome had significantly lower first-year eGFR (p = 0.001), whereas first-year rejection episodes and urine PCR were similar between the groups. After multivariable adjustment, worsening first-year PNI (OR: 2.02, 95% CI: 1.08-3.77, p = 0.028) and worsening first-year CONUT (OR: 2.01, 95% CI: 1.11-3.65, p = 0.022) remained independently associated with the composite outcome. Higher first-year eGFR was independently associated with a lower risk of adverse outcomes. Separate analyses of graft loss and death with a functioning graft supported the primary findings, with stronger associations observed for graft-related outcomes. Conclusions: Early deterioration in nutritional status, reflected by worsening changes in PNI and CONUT during the first post-transplant year, was independently associated with adverse long-term outcomes in KTRs. Serial assessment of these simple and inexpensive nutritional indices may improve long-term risk stratification and help identify patients who could benefit from closer clinical follow-up and individualized nutritional assessment.