Effect of age and gender on kidney function in renal transplant donors: A prospective study

We evaluated the long-term residual renal function in 64 living related kidney donors. Our main objective was to identify baseline factors, including gender and age, that could predict renal impairment after nephrectomy. Forty-four (69%) of the 64 donors were women. The mean ± SEM age of those studied was 36 ± 1.3 years and their mean ± SEM duration of follow-up was 62 ± 4.9 months (range, 6 to 174). Overall mean serum creatinine concentration after kidney donation was increased compared to baseline values (1.13 mg/dl vs 0.92 mg/dl, respectively, p <0.001). At the last follow-up visit, post-nephrectomy mean glomerular filtration rate (GFR) values, adjusted for body surface area, age at donation, baseline serum creatinine and duration of follow-up, measured by ^99mTc-DTPA were significantly lower in women than in men (72.11 ml/min vs 87.17 ml/min, respectively, p = 0.02). At follow-up, mean effective renal plasma flow, adjusted for the same variables, measured by ¹³¹I-hippuran was also significantly lower in women compared to men (318.07 ml/min vs 400.82 ml/min, respectively, p <0.01). Eleven of twelve patients with post-nephrectomy GFR values less than 60 ml/min were women. Following nephrectomy, serum creatinine concentration increased significantly as a function of greater age at donation in women but not in men. Similarly, in women but not in men, follow-up GFR measurements decreased significantly as a function of age after adjusting for baseline serum creatinine and duration of follow-up. Our results raise the possibility that gender and age at donation are significant predictors of residual renal function after uninephrectomy. In addition, they suggest that women at older age may be at higher risk than men of an adverse effect on renal function following renal donation.