Weight gain post-renal transplantation and its association with glomerular filtration rate

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.

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.

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).

There was a great increase in body weight after kidney transplantation. The excessive body weight gain was associated with a better glomerular filtration rate.