Background: Neonatal diabetes mellitus (NDM) is rare, with a prevalence of approximately 1 in 500,000 infants worldwide. NDM may be caused by several different genetic abnormalities, and might either be transient (TNDM) or permanent. Until recently, clinical management of most permanent types of NDM required lifelong subcutaneous insulin treatment. However, due to activating mutations in the genes that encode the adenosine triphosphate-sensitive K(+) channel, some permanent types of NDM have been found to be amenable to oral sulfonylurea therapy. TNDM can last for a median of 12 weeks and completely resolve by 18 months. Although TNDM is typically treated with subcutaneous insulin, this mode of therapy might be difficult for some caregivers.
Case summary: A small for gestational age male infant born at term developed NDM on day of life (DOL) 3. No other factors, such as sepsis, infection, or dextrose-containing intravenous fluids, that could have accounted for the hyperglycemia were present. In addition, there was no family history of DM or hyper-glycemic disorders. The patient was initially treated with subcutaneous regular insulin (0.25 U at a concentration of 10 U/L) q4h PRN for blood glucose concentrations >200 mg/dL. However, due to persistent blood glucose concentration fluctuations, a continuous insulin infusion (0.05 U/kg/h) was started on DOL 7. Because subcutaneous insulin injections could not be administered by the parents outside of the hospital, oral sulfonylurea therapy was attempted. A glyburide oral suspension, prepared by dissolving half of a 1.25-mg tablet in 1 mL of preservative-free, sterile water, was started at 0.2 mg/kg/d in 2 divided doses. The suspension was prepared immediately prior to each dose and was administered via syringe during feedings. On DOL 21, the patient's NDM was managed solely with an oral sulfonylurea, target blood glucose concentrations of 150 to 250 mg/dL were achieved with glyburide 0.7 mg/kg/d in 2 divided doses, and insulin administration was no longer required. On DOL 25, the glyburide dosage was decreased to 0.5 mg/kg/d in 2 divided doses. On DOL 27, the patient was discharged on the same dosage. The patient's NDM subsequently resolved by DOL 49.
Conclusion: An oral sulfonylurea was a useful treatment option in the management of TNDM in this patient.