Risks for donors associated with living kidney donation: meta-analysis

Br J Surg. 2022 Jul 15;109(8):671-678 doi: 10.1093/bjs/znac114.
Abstract
BACKGROUND:

Living kidney donation risk is likely to differ according to donor's demographics. We aimed to analyse the effects of age, sex, body mass index (BMI) and ethnicity.

METHODS:

A systematic review and meta-analysis was undertaken of the effects of preoperative patient characteristics on donor kidney function outcomes, surgical complications, and hypertension.

RESULTS:

5129 studies were identified, of which 31 met the inclusion criteria, mainly from the USA and Europe. The estimated glomerular filtration rate (eGFR) in donors aged over 60 years was a mean of 9.54 ml per min per 1.73 m2 lower than that of younger donors (P < 0.001). Female donors had higher relative short- and long-term survival. BMI of over 30 kg/m2 was found to significantly lower the donor's eGFR 1 year after donation: the eGFR of obese donors was lower than that of non-obese patients by a mean of -2.70 (95 per cent c.i. -3.24 to -2.15) ml per min per 1.73 m2 (P < 0.001). Obesity was also associated with higher blood pressure both before and 1 year after donation, and a higher level of proteinuria, but had no impact on operative complications. In the long term, African donors were more likely to develop end-stage renal disease than Caucasians.

CONCLUSION:

Obesity and male sex were associated with inferior outcomes. Older donors (aged over 60 years) have a larger eGFR decline than younger donors, and African donors have a higher incidence of ESRD than Caucasians.

CET Conclusion
Reviewer: Mr Simon Knight, Centre for Evidence in Transplantation, Nuffield Department of Surgical Sciences University of Oxford
Conclusion: This systematic review and meta-analysis aimed to investigate the impact of donor age, sex, body mass index and ethnicity on the outcome for living kidney donors. Analysis of data from 31 observational studies demonstrated inferior outcomes in male donors, and those with a BMI greater than 30 kg/m2. African donors were found to be more likely to develop renal failure in the long-term than younger donors. Whilst some of the findings are perhaps not too surprising (reflecting the same outcomes in the general population), these data do help in the personalisation of risk assessment for donors and highlight the importance of robust follow-up for higher risk groups. It should be noted that the nature of the review question means that only observational data can be used, most of which is retrospective in nature and prone to high heterogeneity. Nonetheless, this represents a large analysis of the body of published literature on this topic.
Study Details
Aims: This study aimed to investigate the effect of age, sex, body mass index (BMI) and ethnicity on short and long term outcomes for living kidney donors.
Interventions: Electronic databases including Cochrane, Ovid, and Web of Science were searched. Study screening and data extraction were performed by two independent reviewers. The National Heart, Lung, and Blood Institute quality assessment tool was used to assess the methodological quality of the included studies.
Participants: 31 studies were included in the review.
Outcomes: The primary outcome was the effect of donor demographics (ethnicity, BMI, age, and sex) on kidney function. The secondary outcomes included the effect of donor demographics on the incidence of end-stage renal disease (ESRD), serum creatinine level, donor survival, incidence of proteinuria, blood pressure (BP), de novo hypertension, and surgical complications.
Follow Up: N/A
Metadata
Funding: Funding not described
Publication type: Meta-Analysis, Systematic Review
Review registration: PROSPERO - CRD42020207052
Organ: Kidney
Language: English
Author email: m.irene.bellini@gmail.com
MeSH terms: Aged; Female; Glomerular Filtration Rate; Humans; Hypertension; Kidney; Kidney Failure, Chronic; Kidney Transplantation; Living Donors; Male; Nephrectomy; Obesity; Retrospective Studies; Time Factors