SECONDARY HYPOTHYROIDISM IN ADULTS: DIAGNOSIS AND TREATMENT

Abstract

Secondary hypothyroidism is a rare pathology, the diagnosis and treatment of which raises a number of questions and difficulties. There are casuistically rare congenital and acquired forms of this disease. The main causes of secondary hypothyroidism in adults are tumors of the hypothalamic-pituitary region and conditions after surgical and radiation exposure to this area. Hormonally active and inactive pituitary macroadenomas cause the development of acquired secondary hypothyroidism in more than 50% of cases. With radiation therapy for brain tumors, the development of secondary hypothyroidism is possible years after treatment. As with primary hypothyroidism, the clinical manifestations of secondary hypothyroidism are nonspecific. Diagnosis and treatment of this disease are often complicated by its combination with a deficiency of other tropic hormones. The basis for diagnosing secondary hypothyroidism is anamnestic data and laboratory parameters - simultaneous determination of the concentration of free T4 and TSH. The content of free T4 today is also used as the main marker of the adequacy of the L-T4 dose in the treatment of secondary hypothyroidism. The results of recent work make it possible to optimize replacement therapy for secondary hypothyroidism, but the issue of using additional biochemical markers to assess the adequacy of replacement therapy remains unexplored to date.