Decreased Level of Fasting Blood Sugar in a Thyrotoxic Patient after Treatment with Methimazole- A case report

Thyrotoxicosis is the name given to the clinical manifestations of the excess of thyroid hormones in the bloodstream. Thyrotoxicosis may induce increased fasting blood sugar (FBS) in patients of all ages, and has been reported in only few cases. The previous studies have shown that the prevalence of glucose intolerance in hyperthyroidism is 44-65% and may reverse to normal values after achieving euthyroid status. We discuss a 34-year-old woman who presented with thyrotoxicosis with enhanced FBS. The patient had a mild elevated FBS (110 mg/dl) when she had a severe thyrotoxicosis. After treatment with methimazole blood glucose level decreased to 85 mg/dl and by the third visit glucose level decreased to 82 mg/dl. It could be concluded that Mild hyperglycemia may co-exist with thyrotoxicosis and reduce to normal when the patient becomes euthyroid. Thus, early detection and treatment of thyroid hormones oversecretion can resolve the complications of both thyrotoxicosis and associated hyperglycemia.