Early Weight Gain After Transplantation Can Cause Adverse Effect on Transplant Kidney Function

The outcomes of kidney transplant recipients with increased body mass index (BMI) remain controversial. We studied the relationship between changes in BMI and kidney transplant function, especially during the first year after transplantation.

We performed an observational cohort study of all kidney transplant recipients at our center from March 2009 to June 2014 to determine whether changes in BMI were associated with kidney transplant function, as measured by estimated glomerular filtration rate (eGFR). Recipient BMI and eGFR were calculated pre-transplant and at 1, 3, 6, 9, and 12 postoperative months (POM) after transplantation. The correlation between changes in BMI and eGFR was then evaluated.

Eighty-one patients were studied. There was a strong negative correlation between changes in BMI and eGFR from pre-transplant to POM 1 (correlation coefficient, -0.406; P < .0001) and from POM 1 to POM 3 (r = -0.324, P = .004).

We found that increased BMI caused a significant decline in renal function as measured by eGFR, especially in the initial 3 months after kidney transplantation.