The misdiagnosis of hypopituitarism is common due to its rarity and its nonspecific clinical manifestations. Our case report highlights the importance of critical evaluation regarding hypopituitarism as a cause of recurrent hypoglycemia, hyponatremia, and gastrointestinal symptoms in patients with T1DM, as misdiagnosis might be fatal to the patient.We herein report the case of 35-year-old female patient who presented with 18 years of history of well-controlled type 1 diabetes mellitus and a 6-month history of recurrent nausea and vomiting, generalized weakness, hyponatremia, and severe hypoglycemia, despite a reduction in the dose of insulin. She was considered as having "type 1 diabetes and gastroparesis." Four months later, she was diagnosed with hypothyroidism, and 25 μg/d of levothyroxine was prescribed. However, the levothyroxine had to be discontinued 1 week later because of frequent vomiting by the patient.Further evaluation in our hospital revealed low-normal adrenocorticotropic hormone, low-normal serum cortisol, and low 24-hours urinary cortisol excretion. Secondary hypothyroidism and hypogonadotropic hypogonadism were also demonstrated. Based on the endocrinological findings, she was diagnosed with hypopituitarism possibly due to lymphocytic hypophysitis. Diabetic nephropathy was another diagnosis made after kidney biopsy.The patient was treated with 100 mg/d of hydrocortisone intravenously for 2 weeks. After that, she continued on 15 mg/d of prednisone, and then 25 μg/d of levothyroxine was administered.The patient's insulin requirement increased to a premorbid level, the severe hypoglycemia resolved, the physical discomforts were alleviated, and blood electrolytes returned to normal.This uncommon case reinforced the significance of a timely diagnosis and appropriate treatment of hypopituitarism. We recommend that physicians focus their awareness on this potentially life-threatening disease, as it is a condition potentially fatal to the patient if not recognized and treated.
