Long-Term Outcomes Across Age and Risk Profiles in a Caucasian Living Kidney Donor Cohort

Abstract

Living kidney donation achieves excellent recipient outcomes, but increasingly involves older and medically complex donors, while long-term data across age groups remain limited. The Heidelberg Kidney Donor Study followed 632 donors (1991–2020), stratified by age <40 (n=93), 40–60 (n=424), and >60 years (n=115). Primary outcomes were a ≥50% eGFR decline and an eGFR <45 mL/min/1.73 m² at long-term follow-up. Early post-donation adaptation, long-term eGFR trajectories, cardiovascular events, and risk patterns were evaluated. Mean donor age was 50.6±10.6 years (62.5% female). eGFR declined by 26.0% after donation and remained stable thereafter. At a median follow-up of 12 years, ≥50% eGFR decline occurred in 4.8%, 5.3%, and 14.4% of donors aged <40, 40–60, and >60 years, respectively, an eGFR <45 mL/min/1.73m² in 1.2%, 5.3%, and 20.4%. An eGFR <30 mL/min/1.73m² occurred in 1.2%, major adverse cardiovascular events in 4.3%. Age, hypertension, and baseline-eGFR independently predicted renal impairment. Younger donors with hypertension or obesity had up to a 14.3% risk of ≥50% eGFR decline, exceeding the risk in healthy older donors (12.5%). Living kidney donation was associated with stable long-term kidney function after early adaptation, with substantial heterogeneity driven more by baseline renal reserve and comorbidity than chronological age alone.