Importance of renal mass on graft function outcome after 12 months of living donor kidney transplantation.

BACKGROUND: Few studies have directly measured the kidney weight and investigated donor parameters related to it. The aim of this study was to evaluate the kidney weight and its relationship to creatinine clearance (CrCl) after 12 months post-transplantation. METHODS: A total of 123 recipients of renal transplantation from living donors were evaluated. Demographic and anthropometric data from donors and recipients were collected in the pre-operative phase. Data about kidney weight were obtained through kidney measurement using an electronic weighing machine at the moment of transplantation. Glomerular filtration rate (GFR) was estimated through CrCl (modification of diet in renal disease formula) at the 1st, 6th, 12th and 18th month post-transplantation. RESULTS: The mean value of kidney weight was 170 +/- 31 g (166.4 +/- 29.2 g in women and 177.5 +/- 32.5 g in men). The kidney weight had a correlation with the donor's BMI (r = 0.43, P < 0.001) and with the CrCl on the 12th month (r = 0.31, P = 0.001). Using multiple linear regression, the kidney weight could be predicted through the BMI and donor's gender (R(2) = 0.21; P < 0.01). The CrCl after 12 months had a significant correlation with the graft weight/recipient weight ratio and with the donor age (R(2) = 0.22; P < 0.01). CONCLUSION: The kidney weight can be estimated using the donor's gender and BMI. The kidney weight significantly influences the CrCl 12 months after transplantation.