THYROID FUNCTION IN CHILDREN WITH DOWN SYNDROME IN THE REPUBLIC OF MACEDONIA

E. Sukarova-Angelovska, M. Krstevska-Konstantinova, M. Kocova

Department of endocrinology and genetics, University Children Hospital, Skopje, Macedonia

OBJECTIVE. Thyroid dysfunction is well described feature in persons with Down Syndrome. It is the most common endocrine disorder in those persons. Incidence has very wide range in different studies (2-63%) which depends mostly of the age of the patients. Hypothyroidism is more common than hyperthyroidism It is a rare condition in early childhood. The onset of dysfunction may be very subtle as a latent hypothyroidism manifesting only with higher levels of TSH. After 8 years of age, it may become evident with TSH higher than previous, low T4 and fT4 and thyroid antibodies which increase with age. Hypothyroidism is due to an autoimmune process, mostly Hashimoto thyroiditis. This process may influence growth velocity in prepuberal children if not treated. There are several factors that may contribute to abnormal autoimmune response in these children. The treatment of these children is still under consideration.

MATERIAL AND METHODS. 28 children with Down syndrome were evaluated for the values of TSH and T4, using RIA tests. They were divided into 3 groups: 0-6 years (mean chronological age of 1.5 years), 6-15 years (mean chronological age of 10 years) and over 15 years (mean chronological age of 17 years). The results were compared with a standard range.

Results. Of the evaluated children, there are 5 (17.8%) only with higher TSH level in the first group. The main value of T4 in this group was 110 nmol/l while TSH value was 4.7 mU/l. In the second group, 3 (10.7%) patients were with high TSH (main value in the group was 3.7 mU/l) and 2 (7.1%) with low T4 (mean value 97 nmol/l). In the third group all 4 children didn't have thyroid disorders. Thyroid antibodies are planet to be performed during future visits. The children with low T4 wee treated with thyroxin and afterwards parents reported improvement of physical activity and concentration. Some of the children were followed up during the two years, and only in one, thyroid function deteriorated.

CONCLUSIONS. Thyroid dysfunction in patients with Down's syndrome is common in childhood. Annual monitoring of the thyroid status of individuals with Down's syndrome is important for detection of the initial signs of hypothyroidism. Autoimmune thyroid disease is uncommon in young children with Down's syndrome. Treatment should be obtained only when hypothroidism becomes manifest.