Prevalence of weight gain in patients with better renal transplant function.

Aims: This study investigates the association between renal function and change in weight after kidney transplantation.
Methods: Retrospective analyses of 165 transplant patients on maintenance steroids who were followed-up for 6.2 +/- 2.4 years.
Results: 101 males and 64 females participated in the study. Results are expressed as mean +/- SD. At the first post-transplant outpatient visit (time 0), BMI was 25.3 +/- 4.8 kg/m2. It increased significantly by 7.7 +/- 10.8% and 10.9 +/- 12.6% at 1 and 5 years. 18 and 29% of patients had a BMI > 30 kg/m2 at times 0 and 5 years, respectively. Thereafter, diminishing glomerular filtration rate (GFR) was associated with the loss of the excess weight. Multivariate analysis showed that GFR, but not age, race, sex, source of graft, number of HLA mismatches or length of dialysis was significant to post-transplant weight gain. 38 patients gained weight > 1 SD above the mean of the population and were designated the high weight gain (HWG) group. 41 patients gained weight < the mean - 1 SD of the population and were designated the low weight gain (LWG) group. GFR in the high and low weight gain groups at time 0 was 71.8 +/- 20.3 ml/min/1.73 m2 and 66.4 +/- 23.1 ml/min/1.73 m2, respectively (p = NS), as compared to 77.4 +/- 23.3 ml/min/1.73 m2 and 61.5 +/- 24.5 ml/min/ 1.73 m2 at 6 months, respectively (p < 0.01) and continued to be significant thereafter (72.7 +/- 17.2 ml/min/1.73 m2 and 58.9 +/- 19.8 ml/min/1.73 m2, p < 0.05 at 6 years).
Conclusions: Patients with relatively better renal transplant function gained more weight, suggesting a pivotal role of improved appetite on weight gain post transplantation. Most of the weight gain occurred during the first year.