Abstract
Background Kidney transplantation is the best possible option for patients reaching end-stage renal disease. Despite the excellent outcomes for recipients in terms of graft survival, the evidence regarding outcomes for donors is conflicting, and there is uncertainty regarding the long-term complications of kidney donation. Thus, our study aimed to assess the change in kidney function following donor nephrectomy and identify the associated comorbidities in a Sri Lankan cohort. Methodology This descriptive retrospective study was conducted at the donor clinic of Unit 1 at the National Hospital of Sri Lanka from July 2021 to November 2021. A total of 102 donors who had undergone donor nephrectomy since 2005 were included. Results The mean duration of the study population since donation was six years, with a standard deviation of ±3.20. The minimum duration since donation was one year, and the maximum was 14 years. The median interquartile range (IQR) preoperative glomerular filtration rate (GFR) was 94.50 (19) ml/min; the GFR on discharge was 66.50 (29) ml/min; and the current median GFR was 73.86 (23.31) ml/min. These changes in the GFR were statistically insignificant, with a p-value of 0.062. The preoperative estimated glomerular filtration rates (eGFRs) of all 102 donors (100%) exceeded 60 ml/min/1.73 m(2), while the current values showed that 72 members of the study group (70.6%) had values exceeding 60 ml/min/1.73 m(2), and 30 members of the study group (29.4%) had values of less than 60 ml/min/1.73 m(2). The difference in eGFR values between the preoperative and current states was <15 in 24 patients (23.5%). eGFR values between 15 and 30 were observed in 49 members of the study population (48%), while eGFR values of >30 were reported in 29 patients (28.4%). The median preoperative (IQR) urine protein creatinine ratio (UPCR) was 0.00 (0.05) mg/mmol, and it changed to 0.01 (0.14) mg/mmol. Serum creatinine (SCr) levels increased in 89 members of the study population (98.9%) while remaining unchanged in one member (1.1%). Both UPCR and SCr values showed statistically insignificant changes following donation (p-values of 0.332 and 0.119, respectively). In terms of comorbidities, 18.8 percent of the patients (n=19) had hypertension before surgery, and the prevalence of hypertension increased to 31.0 percent (n=31) after surgery. Preoperatively, obesity was found in 11.1% (n=11) and, postoperatively, 12.1% of the cases (n=12) were associated with obesity. Among the data on the association between the GFR and the factors affecting change in the kidney function, a statistically significant association was observed between age and GFR values, with a p-value of <0.001. However, neither gender, smoking, body mass index, income, duration since donation, the frequency of follow-up visits, comorbidities such as hypertension, nor the type of donor showed any association with GFR. Likewise, the development of proteinuria was not associated with any of these factors. Notably, renal functions (GFR, SCr, and UPCR) and duration after donation showed no statistically significant associations. Conclusion The GFR tended to drop immediately postoperatively, but no sustained further drop in the GFR over time was observed. Similarly, no statistically significant risk of developing proteinuria with kidney donation was observed. In our findings, older age was the only factor related to an increased likelihood of a decrease in the GFR following donor nephrectomy.