An epidemiologic survey of thyroid enlargement among schoolchildren in a non-endemic area

In 534 unselected schoolchildren aged 6-14 yr from the greater Athens area the size of the thyroid gland was assessed by palpation, and information was obtained on sex, age, height, weight, skinfold thickness, socioeconomic class, eye colour and urinary iodine excretion. The results were analysed by discriminant analysis. Altogether 14% of these children had a thyroid enlargement (7% had a definite goitre and another 7% a smaller enlargement). The set of variables studied were significantly discriminatory (Wilk's lambda 0.926, p approximately equal to 0.004). Most of the discrimination was accounted for by height (positive association, b coefficient 0.0114, SE 0.0029, t = 3.95) and weight (negative association, b coefficient 0.0107, SE 0.0030, t = 3.61). No other parameter, including iodine excretion, showed a significant difference between goitrous and nongoitrous. It is concluded that the only genuine difference is that goitrous are heavier for a given height or shorter for a given weight, i.e. more obese. The reason for which obesity protects from sporadic nontoxic goitre is not entirely clear, but probably both nutritional and genetic factors are involved.