Background: Old age is a known risk factor for chronic kidney disease as functional nephron loss occurs starting at the age of 60. This study aimed to assess whether old age kidney donors with larger kidney volumes have lower risks of developing chronic kidney disease after donor nephrectomy.
Methods: A retrospective analysis of 1,087 living kidney donors was performed. The remnant kidney whole volume was measured using preoperative computed tomography through a fully autosegmentated program. A univariate and multivariate analysis for development of chronic kidney disease (CKD) postdonor nephrectomy was performed using preoperative factors including baseline characteristics, laboratory results, and remnant kidney volume.
Results: Compared to young donors (≤60 years, n=1,006), old age donors (>60 years, n=81) had lower baseline estimated glomerular filtration rate (95.6±9.5 vs. 104.5±14.4, P<0.001). Other baseline characteristics, including weight, kidney whole volume quartile distribution, and gender were similar in both groups. The cumulative CKD-free survival for 5-years was worse in old age donors (hazard ratio, 3.36; 95% confidence interval [CI], 2.14–5.26; P<0.001). Multivariate Cox regression model for CKD in old age donors showed that male gender was a significant risk factor (odd ratio [OR], 4.834; 95% CI, 1.746–13.381; P<0.002) and large kidney whole volume to weight ratio was a protective factor against CKD (OR, 0.263; 95% CI, 0.054–1.272; P<0.097).
Conclusions: Large kidney volume to weight ratio acts as a protective factor against the development of chronic kidney disease in old age donors.