Diabetes mellitus in a girl with thyroid hormone resistance syndrome: a unlooked feature for this condition?

The syndrome of resistance to thyroid hormone(RTH) is characterized by elevated serum free thyroid hormones (FT4and FT3) in the presence of unsuppressed TSH levels, reflecting resistanceto the normal negative feedback mechanisms within the hypothalamus andpituitary. The degree of resistance within peripheral tissues determineswhether thyrotoxic clinical features are associated with this condition.Classic features include attention deficithyperactivity disorder, growth delay, tachycardia, and goiter. However, otherfeatures, such as frequent ear nose and throat infections, hearing deficit, anddecreased bone mass have recently been recognized. The phenotype of RTH isvariable, with most patients presenting with mild to moderate symptoms.In this report we describe a girlwith familiar RTH and diabetes mellitus. This is, to our acknowledge, the firstreport regarding this association. Near 1 year after long-term triiodothyroaceticacid (Triac) therapy, we evidence a reduction of thyroid hormone levels, with anamelioration of insulin resistance. The possible interactions between these disordersare discussed.