Renal Consequences of Diabetes After Kidney Donation

Whether diabetes after kidney donation is associated with an accelerated GFR decay in the remaining kidney has not been studied. We determined the incidence of diabetes in kidney donors, and compared GFR change over time in diabetic to nondiabetic donors, in addition to the effect of diabetes mellitus (DM) on the development of proteinuria, hypertension, and end-stage renal disease (ESRD). Of the 4014 donors, 309 (7.7%) developed diabetes at a median age of 56.0 years and after a median of 18 years after donation. The difference in annual estimated GFR (eGFR) change between diabetic and nondiabetic donors in the 7 years before the development of DM was −0.08 mL/min/year; p = 0.51. After DM development, the difference was −1.10 mL/min/year for diabetic donors with hypertension and proteinuria, p < 0.001; −0.19 for diabetic donors with hypertension but no proteinuria, p = 0.29; −0.75 mL/min/year for diabetic donors with proteinuria but no hypertension, p = 0.19; and −0.09 mL/min/year for diabetic donors without proteinuria or hypertension, p = 0.63. When DM was considered as a time-dependent covariate, it was associated with the development of proteinuria (hazard ratio [HR] 2.65, 95% confidence interval [CI] 1.89–3.70; p < 0.001) and hypertension (HR 2.19, 95% CI 1.74–2.75; p < 0.001). It was not, however, associated with ESRD. eGFR decline after DM development exceeds that of nondiabetic donors only in diabetic donors with concomitant proteinuria and hypertension.