Introduction: Living donors provide the majority of kidneys for transplantation in low middle-income countries.  Long-term consequences of living donation are a concern of the transplant community, where efforts were made to optimize selection criteria, prevent adverse consequences, and establish effective measures to maximize safety of donors. In low-middle-income countries, the long-term outcome of kidney donors is largely unknown, with few reports on donor outcomes. In this paper, we evaluate renal function by creatinine clearance and proteinuria in kidney donors aged 50 years or older after 15 years of donation, followed up in a dedicated clinic.
Methods:  This retrospective study includes 719 kidney donors. Those who were aged 50 years or more at 15 years after donation.  Their 24-hour urinary creatinine clearance (CrCl) ml/min/1.73m2 and protein (mg/24 hours) were estimated yearly till their last follow-up before or upto 2023.  The donors were divided into three groups:  group 1, 50-60 years; group 2, 61-70 years, and group 3, >70 years.  Statistical analysis was performed using SPSS version 25. 
Results:  Of the 719 donors, 414 were in group 1, 221 in group 2, and 54 in group 3.  The mean age in years of group 1 was 54.61±31, in group 2, 64.58±2.7, and in group 3, 76.13±5.9. Post-donation CrCl in group 1 at 15 years was 76.0±21.3 and 70.1±21.275 at 35 years, in group 2, 71.3±17.05 at 15 years and 60.5±7.78 at 36 years, and in group 3, 65.3±13.1 at 15 years and 58.0±16.8 at 28 years.  Of the 719 donors, 59 (8.2%) had protein excretion>1000 mg/24 hours.  In group 1, 31(6.9%) in group 2, 21(9.5%), and group 3, 7(12.9%). Mean protein excretion (mg/24 hours), excluding those with >1000 mg/24 in group 1 was 120±128 at 15 years, and 127±81.3 at 35 years.  In group 2, 109±96.0 at 15 years, and 404±333 at 36 years, and in group 3, 138.6±140.9 at 15 years, and 224±273.6 mg/24 hours at 28 years.  In the period beyond 15 years, new-onset hypertension was found in 35(4.8%) and diabetes in 21(2.9%).  
Conclusion:  Living kidney donors who are older than 50 years after 15 years of donation maintain adequate renal function (60-70 ml/min/1.73m2) beyond 76 years of age and 35 years post-donation.  Treatment of hypertension and other medical conditions prevented diverse outcomes.