Diabetic ketoacidosis induced by long-acting growth hormone in a child without preexisting diabetes.

Long-acting growth hormone (LAGH) formulations improve medication adherence in children with growth hormone deficiency. Although transient insulin resistance and mild hyperglycemia are recognized effects of growth hormone therapy, diabetic ketoacidosis (DKA) in patients without prior diabetes is rare. We report a case of severe DKA shortly after initiation of lonapegsomatropin in an adolescent with hypopituitarism without preexisting glucose abnormalities. A 13-year-old boy with obesity, normal fasting glucose, and hypopituitarism receiving levothyroxine, hydrocortisone, and desmopressin replacement therapies following treatment of a suprasellar nongerminomatous germ cell tumor initiated treatment with lonapegsomatropin at 0.23 mg/kg/week. Two days after the administration of the first dose, he presented critically ill with hyperglycemia, severe metabolic acidosis, and ketonuria consistent with DKA. Hemoglobin A1c was 5.7% (reference range, <5.7%), type 1 diabetes autoantibodies were negative, and C-peptide was elevated, suggesting preserved endogenous insulin secretion. Diabetic ketoacidosis resolved with insulin and fluid therapy, and the patient remained normoglycemic after discontinuation of growth hormone therapy. This case suggests that acute LAGH-induced insulin resistance, potentially compounded by glucocorticoids and obesity, may precipitate transient DKA even in patients without prior glucose abnormalities. Close glucose monitoring should be considered when initiating LAGH therapy in high-risk patients.