Case report: hypoglycemia secondary to methimazole-induced insulin autoimmune syndrome in young Taiwanese woman with Graves' disease

Extremely high-dose insulin requirement in a diabetic patient with psychiatric illness: A case report

Severe insulin resistance is defined as the need of insulin requirement of more than two units per kilogram of body weight. It is rarely seen in diabetic patients. Common causes of severe insulin resistance include severe insulin resistance syndromes, drugs, endocrine disorders, factitious causes, lipodystrophy, increased insulin clearance, and impaired insulin absorption. Here, we describe a diabetic patient with major depressive disorder who was prescribed a maximum of 282 units (4.9 units/kg) of insulin a day. However, the cause in this patient was pseudo-resistance to insulin due to the inappropriate use of insulin by the patient. The ability to maintain her glycemia in the target range with lower doses of insulin was confirmed after the patient was admitted to the hospital. It is, therefore, crucial to systematically address any patient who requires an exceptionally high dose of exogenous insulin, starting with technical issues (injection technique, site of administration, or insulin storage), medication adherence, or medication errors.

Safety of Antithyroid Drugs in Avoiding Hyperglycemia or Hypoglycemia in Patients With Graves' Disease and Type 2 Diabetes Mellitus: A Literature Review

Graves' disease (GD) may increase the difficulty of glucose control in patients with type 2 diabetes mellitus (T2DM). Therefore, selecting a drug with limited blood glucose side effects is an important issue in patients with T2DM and GD. Antithyroid drugs (ATDs) including propylthiouracil (PTU), methimazole, and carbimazole are commonly prescribed for the treatment of GD. Here, we review and summarize the literature from the last 10 years and discuss the effects of current ATDs used for GD for blood glucose control in patients with T2DM. A search of the literature published between January 1, 2012 and December 1, 2022 was conducted using three major medical databases: Google Scholar, Ovid Medline, and Scopus. An initial search was conducted on PubMed using the MeSH terms "propylthiouracil," "methimazole," "carbimazole," and "hyperglycemia" or "hypoglycemia" in academic databases. All articles included "Graves' disease" and "type 2 diabetes mellitus" in the title. Based on the results of previous studies, the hyperglycemic and hypoglycemic side effects of ATDs can be explained by several possible mechanisms. The most widely accepted hypothesis is that sulfhydryl group drugs (e.g., methimazole and carbimazole) cleave the disulfide bond of insulin and enhance its immunogenicity, resulting in hypoglycemia. Moreover, some reports have indicated that methimazole is associated with hypoglycemia; therefore, if the patient has a history of autoimmune diseases, it is necessary to consider whether to change drugs or actively track the production of autoimmune antibodies. In non-diabetic and diabetic patients with GD, the hyperglycemic and hypoglycemic side effects of PTU (on glycemic variation) were less than that of thiamazole. However, as relatively few reports have investigated the side effects of blood sugar changes, further research is necessary to confirm these effects. In addition to autoimmune diseases, drug side effects may need to be considered. These findings provide considerations for clinicians to select more appropriate ATDs for patients with GD and T2DM, and implement improved care guidelines.