Effect of weight change after renal transplantation on outcomes of graft survival.

Background And Objective: After kidney transplantation, there is an overall increase in weight, which may increase the risk of chronic kidney disease (CKD) and graft loss. But, not all patients gain weight, and the impact on the graft of this different evolution has not been well studied. The objective was to determine the causes of this different evolution and its effect on the graft.

Patients And Methods: Retrospective single-center cohort study of 201 patients followed up after transplantation, analyzing the determinants of the variation in weight at one year using logistic regression, and its effect on graft survival at the end of follow-up using Cox regression.

Results: Globally, there was an average weight gain of 4.5 kg in the first year, but 26.6% lost weight. 37.2% increased their BMI, while 9.5% decreased it. The determinants of the different evolution of weight were age (OR for every 10 years: 0.6, p = 0.002), previous dialysis modality (ref. hemodialysis) (OR 0.3, p = 0.003), and BMI before transplantation (OR 0.9, p = 0.017). The different evolution of weight did not influence the final situation of the graft. The BMI at one year did influence as a continuous variable (HR 1.3, p = 0.003), and obesity, with a worse evolution (HR 7.0, p = 0.025).

Conclusions: Although not all patients gain weight after kidney transplantation, the different evolution of weight does not influence graft survival.