Longitudinal mortality risks and kidney functional outcomes in Japanese living kidney donors

Previous studies suggested that living kidney donors do not have a higher risk of death or kidney failure than the general population. However, living kidney donor risk is controversial. Furthermore, only a few studies have evaluated long-term kidney function after kidney donation.

This study evaluated Japanese kidney donor' long-term outcomes, including mortality and kidney function. From 1965 to 2015, 230 donors (76 males, 154 females, and a median age of 54) were enrolled in this study. The median observation period was 11.0 (range, 0.3-41.0) years.

In total, 215 donors were still alive, and 15 had died. Causes of death included malignancies, cardiovascular disease, pneumonia, suicide, gastrointestinal bleeding, and kidney failure. Actual donor survival rates at 10, 20, and 30 years were 95.3%, 90.7%, and 80.9%, respectively. These values were comparable to age- and gender-matched expected survival. Long-term kidney function after donation was evaluated in 211 donors with serum creatinine data. Two donors developed kidney failure 24 and 26 years post-donation, respectively. The percentage of donors whose estimated glomerular filtration rate (eGFR) remained ≥45 mL/min/1.73 m² at 10, 20, and 30 years after donation were 84.2%, 73.0%, and 63.9%, respectively. Survival rates of donors with eGFR <45 mL/min/1.73 m² were comparable to those in persons with eGFR >45 mL/min/1.73 m².

Our findings revealed that kidney donors did not have a higher long-term risk of death than the general population. Although some donors showed decreased kidney function after donation, kidney function did not impact their survival.