Endemic infantile hypothyroidism in a severe endemic goitre area of central Africa
Vanderpas, J.; Bourdoux, P.; Lagasse, R.; Rivera, M.; Dramaix, M.; Lody, D.; Nelson, G.; Delange, F.; Ermans, A.M.; Thilly, C.H.
Clinical Endocrinology 20(3): 327-340
1984
ISSN/ISBN: 0300-0664 PMID: 6723080 DOI: 10.1111/j.1365-2265.1984.tb00089.xDocument Number: 405934
Thyroid function and exposure to dietary goitrogenic factors (iodine deficiency and thiocyanate overload was 3.23 .+-. 0.12 nmol/l during the 1st yr asnd remained stable thereafter. The frequencies of low T4 (T4 < 77 nmol/l), high TSH TSH (TSH > 50 mU/l), and low T4 and T3 (T3 < 1.69 nmol/l) were twice as high at 5-7 yr as in the 1st yr (respectively, 65, 42 and 15%). The urinary iodide concentration of the children was stable and low throughout the study period. By contrast, serum thiocyanate concentration which was high at birth (129 .+-. 5 .mu.mol/l) decreased to normal values between 3 and 12 mo. of age and increased again during and after weaning (1-3 yr of age) to reach a value of 138 .mu.mol/l which was comparable to that observed in adults in the same area. Thiocyanate concentration was high (133 .+-. 7 .mu.mol/l) in the mothers' serum but low in the mothers' milk (57 .+-. 3 .mu.mol/l) (P < 0.001). Multivariate analysis showed that both I deficiency and thiocyanate overload were explanatory factors of the serum levels of T4, FT4 and TSH in children. Infantile hypothyroidism is much more frequent at 5-7 yr of age than at birth or during the 1st year of life. The deterioration in thyroid function during and after weaning is linked to persistent I deficiency accompanied by an increase in thiocyanate overload. The variability in the age of onset, the severity, and the duration of infantile hypothyroidism might explain the wide range of psychomotor and physical abnormalities observed in a large proportion of subjects in this area.