Objective: Obesity may be a risk factor for renal graft loss. The purpose of this study was to assess weight gain and its association with glomerular filtration rate after kidney transplant.
Methods: This retrospective analysis of 152 adult renal transplant outpatients (77 males, 75 females; mean age, 45.6 +/- 10.1 years) with at least 6 months posttransplantation (post-tx) included body weight and creatinine clearance (CrCl) measured pretransplantation (pre-tx) as well as at 6 months (post-tx1), 1 year (post-tx2), 5 years (post-tx3), 10 years (post-tx4), 15 years (post-tx5), and 20 years (post-tx6) post-tx. Weight gain was determined by subtracting patient preoperative weight from the post-tx weights.
Results: The weight gain post-tx versus pre-tx was progressive and significant (P < .001) post-tx1, 8.7 +/- 10.9% (n = 152); post-tx2, 12.4 +/- 11.5% (n = 150); post-tx3, 16.6 +/- 14.8% (n = 102); post-tx4, 20.1 +/- 18.1% (n = 47); post-tx5, 20.8 +/- 19.8% (n = 17); and post-tx6, 21.0 +/- 32.5% (n = 11). There was a positive and significant correlation between weight gain and CrCl during most times post-tx: post-tx2 (r = 0.32; P < .000); post-tx3 (r = 0.54; P < .0001); post-tx4 (r = 0.47; P = .01); and post-tx6 (r = 0.92; P < .001).
Conclusions: There was a great increase in body weight after kidney transplantation. The excessive body weight gain was associated with a better glomerular filtration rate.