Glucose intolerance and diabetes are observed in the long-term follow-up of nonpancreatectomized patients with persistent hyperinsulinemic hypoglycemia of infancy due to mutations in the ABCC8 gene.

Objective: To report the long-term follow-up of three nonpancreatectomized patients with persistent hyperinsulinemic hypoglycemia of infancy due to mutations in the ABCC8 gene.

Research Design And Methods: Oral glucose tolerance test (OGTT) and venous 24-h glucose-insulin profile were performed yearly from adolescence.

Results: Patient 1 (now aged 31 years) developed insulin-dependent diabetes at the age of 25 years. In patient 2 (now aged 17 years), impaired fasting glucose and a diabetic OGTT response with normal A1C values have been observed since the age of 10 years. In patient 3 (now aged 24 years), intolerant OGTT response and hyperglycemic episodes with normal A1C have been observed since the age of 16 years. All patients presented relatively low insulin levels during hyperglycemia, normal BMI, and negative autoantibodies (GAD antibody, insulinoma-associated protein 2, and islet cell antibody).

Conclusions: Development of glucose metabolism impairment ranging from glucose intolerance to insulin-dependent diabetes is observed in the evolution of these patients.