The effect of body mass index at the time of donation on postoperative and remote consequences of nephrectomy in 189 living-related kidney donors

Objective: To analyse the effects of baseline body mass index (BMI) on the postoperative and remote consequences of nephrectomy in living kidney donors, as body weight is conventionally used as an exclusion criterion for kidney donation and a BMI of 35 kg/m^2 is often required. Patients and methods: We retrospectively studied 189 living-related kidney donors who had their nephrectomy between 1986 and 2009 in our urology department. We recorded the BMI at the time of donation, and analysed variables after surgery, and clinico-biological factors remotely. The effect of the initial BMI after surgery and much later after nephrectomy was assessed. Results: The mean follow-up was 9.28 years. The mean (range) BMI at the time of donation was 26.5 (18.5–41.1) kg/m^2; 33% of donors were overweight (BMI 25–30) and 21% were obese (≥30), with 10.5% having a BMI of 35 kg/m^2. The duration of hospitalisation was not related to the BMI. There was no significant difference between the mean BMI of donors with a simple postoperative history and donors who had complications after surgery. Among obese donors, only 7.7% had a complication, which was a surgical-site infection in all cases. The baseline BMI was higher among donors who maintained normal renal function and no proteinuria than in donors with impaired renal function and/or proteinuria; the difference was not significant. The occurrence of hypertension or diabetes was independent of baseline BMI. Donors with dyslipidaemia had no significantly greater baseline BMI than those with no dyslipidaemia. Conclusion: The BMI at the time of kidney donation does not seem to influence the short- or long-term consequences of nephrectomy in living donors.