Vegetative status of children living in conditions of iodine deficiency

Abstract

The autonomic balance has been evaluated by rhythmographic methods in 132 children aged 11-12 years living in a zone of moderate iodine insufficiency (Bishkek) with urinary iodine levels 35±7.7 mcg/liter and incidence of goiter 43.6%. By the results of ultrasonic examination, the examinees were divided into 3 groups: 1) with thyroid less than 6 cm³; 2) with thyroid of 6-10 cm³; and 3) with thyroid larger than 10 cm³. The tone of the sympathetic compartment of the autonomic nervous system was decreased in group 3 (relative vagotonus). The levels of iodine excretion, triiodothyronine, TTH, and hydrocortisone were virtually the same in all groups. The level of T4 was significantly decreased in group 3. Hence, the sensitivity of the negative feedback in the hypothalamo-pituitary-thyroid system is decreased in vagotonic children, and the thyroid in these children is more liable to hyperplasia under conditions of iodine deficiency.