Living Kidney Donor with Impaired Glucose Tolerance and a Family History of Diabetes
A 44-year-old man volunteers to donate a kidney to his brother, who has end-stage kidney disease from diabetic nephropathy. The donor has a body mass index of 29 kg/m², a fasting glucose of 108 mg/dL, and a 2-hour oral glucose tolerance test of 156 mg/dL. His HbA1c is 5.9%. He has no hypertension, his blood pressure is 124/78 mmHg, and his estimated GFR is 96 mL/min/1.73 m² by creatinine-based equation. He has a strong family history: his father and two paternal uncles have type 2 diabetes. He is motivated and asks whether he can still donate. The transplant center uses a multidisciplinary donor selection committee.
1. Evaluate this candidate's metabolic risk and determine whether he is an acceptable living kidney donor. What additional testing or risk stratification would you require?
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This candidate has prediabetes: fasting glucose 108 mg/dL (impaired fasting glucose), 2-hour OGTT 156 mg/dL (impaired glucose tolerance), and HbA1c 5.9%. He also has a BMI of 29 kg/m² and a strong family history of type 2 diabetes. These features substantially increase his lifetime risk of developing diabetes and, consequently, of kidney disease after donation. Living donation removes reserve and is associated with a modest increase in risk of end-stage kidney disease, so donor selection should prioritize long-term safety.
Most centers would consider prediabetes a relative contraindication, not an absolute one, and would require: (1) Repeat confirmatory testing (fasting glucose, HbA1c, OGTT) to exclude transient stress hyperglycemia. (2) Assessment of insulin resistance and consideration of lifestyle intervention with weight loss before donation. (3) Discussion of the increased risk with the donor and recipient, documented in informed consent. (4) Multidisciplinary committee review with nephrology, endocrinology, and ethics input. (5) Long-term follow-up plan including annual glucose testing and kidney function monitoring. Some centers would decline donation in a prediabetic donor with a strong family history; others would accept after risk counseling and risk-factor modification. The judgment hinges on balancing donor autonomy against the duty to protect the donor's long-term health.
2. How would you counsel the recipient brother about accepting a kidney from a donor with prediabetes, and what are the alternatives?
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The recipient should be told that the donor kidney is anatomically and functionally suitable now, but that the donor's metabolic risk raises the possibility of future donor health problems and, rarely, of donor-derived disease. The more immediate issue is the recipient's own risk: the recipient has diabetic nephropathy, and recurrence or progression of diabetic kidney disease in the allograft is a major concern regardless of donor. The donor's prediabetes does not transmit diabetes, but shared family history and lifestyle mean the recipient remains at high risk for recurrent diabetic injury.
Counseling should cover: (1) Short-term outcomes are likely similar to other living-donor kidneys if the donor remains healthy. (2) Long-term donor follow-up is essential; if the donor develops diabetes or kidney disease, this affects the donor, not the recipient's allograft directly, but it may affect future donor availability for others. (3) Alternatives include remaining on the deceased-donor waitlist, pursuing a paired exchange or nondirected donor, or accepting the living donor with a structured risk-management plan. (4) Recipient risk-factor control - glycemic control, blood pressure, and use of renoprotective agents - is critical. The decision should be shared, documented, and reviewed by the selection committee.