Abstract
A 70-year-old woman suffered from hypoglycemic symptoms three or four hours after glucose intake for three months. At this time, the patient felt she had perspired more than in previous years. A diffuse elastic goiter without tenderness was palpable. Transient hyperthyroid state with little uptake by 123I-thyroid scintigram was shown and diagnosed as silent thyroiditis. Oral glucose ingestion test (OGTT) showed normal glucose response but high insulin response and hypoglycemia occurred at 240 minutes. We diagnosed reactive hypoglycemia for glucose intake. The frequency of hypoglycemia reduced after the glucose intake decrease. Hypoglycemia did not occur after glucose intake in the euthyroid state. Then OGTT showed a borderline pattern and delayed hyperinsulinemic response. Reactive hypoglycemia may have been the result of transient hyperthyroid state in the background of the pre-diabetic stage.
