methimazole and Insulinoma

Hypoglycemia is common in patients with glucose regulation disorders and related diabetic treatments but is rare in nondiabetic patients. Severe hypoglycemia can cause harm to patients' cognition, consciousness, central nervous system, cardiovascular and cerebrovascular system, and even death. However, the most fundamental way to control hypoglycemia is to identify the cause and deal with the primary disease. This article introduces 3 cases of nondiabetic hypoglycemia with different causes, aiming to improve our understanding of nondiabetic hypoglycemia and improve the ability of early diagnosis and differential diagnosis.. Case 1 is a 19-year-old female with a history of recurrent coma, and magnetic resonance imaging and endoscopic ultrasound of the pancreas suggest insulinoma. Case 2 is a 74-year-old male with a history of viral hepatitis, and computerized tomography shows multiple nodules in the liver, which is diagnosed as liver cancer. Case 3 is a 39-year-old female with a history of taking methimazole, who tested positive for insulin antibodies, and was diagnosed with insulin autoimmune syndrome.. All 3 patients were diagnosed with nondiabetic hypoglycemia, but the causes varied, and included insulinoma, non-islet cell tumor-induced hypoglycemia, and insulin autoimmune syndrome.. Case 1 underwent pancreatic tail resection; case 2 refused anti-tumor treatment and received glucose injections for palliative treatment only; and case 3 stopped taking methimazole.. After surgery, the blood sugar in case 1 returned to normal, and the blood sugar in case 2 was maintained at about 6.0 mmol/L. The symptoms of hypoglycemia gradually improved in case 3 after stopping the medication.. Non-diabetic hypoglycemia requires further examination to clarify the cause, and the correct differential diagnosis can provide timely and effective treatment, improving the patient's prognosis.

Topics: Adult; Aged; Blood Glucose; Early Detection of Cancer; Female; Humans; Hypoglycemia; Insulin; Insulinoma; Male; Methimazole; Pancreatic Neoplasms; Young Adult

Hypoglycemia is an emergent condition with many causes, including underlying diabetes mellitus either with the use of insulin or oral anti-diabetic medications for glucose control, and organ (heart, hepatic, or renal) failure. Insulin autoimmune syndrome (IAS) can also cause hypoglycemia, however it is relatively difficult to diagnose as it is rare clinically. Although uncommon, IAS can be life threatening in patients with persistent hypoglycemia.. We report the case of a 27-year-old female with underlying Graves' disease who was treated with methimazole (MTZ). After 6 weeks of treatment, she developed hypoglycemia symptoms accompanied by dizziness and cold sweating. We excluded underlying diabetes mellitus, the use of insulin or oral anti-diabetic medications, and organ failure.. Laboratory data showed elevated insulin and C-peptide levels. Therefore, insulinoma and IAS were suspected. Abdominal computed tomography and magnetic resonance imaging ruled out insulinoma, and MTZ-induced IAS was finally diagnosed.. The hypoglycemia symptoms resolved after MTZ was switched to propylthiouracil, confirming the diagnosis of IAS.. This case emphasizes the significance of life-threatening MTZ-induced IAS. IAS should be suspected in patients who develop spontaneous hypoglycemia, especially in those with underlying Graves' disease receiving MTZ who present with hyperinsulinism.

Topics: Adult; Autoimmune Diseases; Diabetes Mellitus; Female; Graves Disease; Humans; Hyperinsulinism; Hypoglycemia; Insulin; Insulinoma; Methimazole; Pancreatic Neoplasms

"Autoimmune" hypoglycemia is a syndrome consisting of fasting hypoglycemia, hyperinsulinemia, and insulin-binding antibodies in a patient who has never been exposed to exogenous insulin. The stimulus for insulin-antibody formation and the mechanism of the hypoglycemia in this condition remain unknown. Three patients with this rare syndrome had severe hypoglycemia of limited duration. Two had received a drug containing a sulfhydryl group (methimazole and penicillamine) as treatment for an autoimmune disorder (Graves' disease and rheumatoid arthritis, respectively). A third patient who underwent surgery for a suspected insulinoma was found to have pancreatic beta cell hyperplasia. Drugs containing a sulfhydryl group may have a role in the etiology of the syndrome. Additionally, our findings suggest a relationship between circulating insulin antibodies and beta cell hyperplasia.

Topics: Autoantibodies; Diagnosis, Differential; Female; Humans; Hyperplasia; Hypoglycemia; Insulin Antibodies; Insulinoma; Islets of Langerhans; Male; Methimazole; Middle Aged; Pancreatic Neoplasms; Penicillamine; Syndrome