Abstract
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OHD) was well maintained after diagnosis is a 1-year-old girl in administering hydrocortisone (HC), with clitoral plasty done while maintaining hydrocortisone at age 3. She was treated with 0.75 mg/day of dexamethasone (Dex) after HC was discontinued when the woman reached adulthood with no signs or symptoms of iatrogenic Cushing syndrome (CS). The Dex dose was increased to 2.5 mg when the woman was 27, when glucocorticoid activity was potentially equivalent to 60 mg of HC because the urology physician in charge misunderstood the Dex dose used due to undetectable serum cortisol. The woman gradually gained weight, reaching over 100 kg by age 30 due to the inappropriately high Dex dose. This continued with inappropriately high predonisolone or Dex dosage until she was finally diagnosed with diabetes and increased HbA1c at age 34. Glimepiride had already been started elsewhere in outpatient diabetes treatment and she was admitted to our hospital due to insufficient hyperglycemic control. Family history showed that her father and brother had already been diagnosed with type 2 diabetes. A physical examination when she weighed 98 kg but was 158 cm tall showed Cushingoid signs such as moon face, buffalo hump, and central obesity. No diabetic complications such as microangiopathy or arteriosclerosis were seen. We diagnosed her as suffering from iatrogenic CS and steroid-induced diabetes with hyperinsulinemia. Glimepiride was discontinued and combination therapy with metformin and voglibose started. We changed from Dex to HC, gradually reducing glucocorticoid replacement. Her weight decreased as the HC dose was lowered and blood glucose levels improved. An appropriate amount of glucocorticoid is generally acceptable for suppressing adrenal androgen secretion sufficiently without adversely affecting hypothalamic-pituitary-adrenal axis function during 21-OHD treatment. It is difficult to reduce excess androgen without administering a high glucocorticoid dose that could induce iatrogenic CS, as in our present case. Glucocorticoid use should be considered carefully in replacement therapy, especially in elderly subjects with 21-OHD at risk for diabetes mellitus.
