[Goiter epidemiology in South Tirol].

To ascertain the prevalence of goitre among schoolchildren in South Tyrol (uncontrolled voluntary iodine salt prophylaxis), the size of the thyroid gland was determined by palpation and ultrasound in 1,013 of 1,224 children, aged 6 to 14 years (547 boys, 466 girls), selected by statistically criteria. At the same time, to assess thyroid function, total and free fractions of T3 and T4, and TSH were measured, while iodine supply was determined by measuring urinary iodine. Stage Ia goitre was diagnosed by palpation in 157 children, stage Ib in 18 and stage II in two (goitre prevalence of 1.97% according to WHO criteria). Mean thyroid volume as determined by ultrasound was 4.26 (0.8-23.4) ml. As expected, it increased with age and body surface area: it was 2.55 +/- 0.49 ml in 6-year olds, 3.83 +/- 0.42 ml in 10-year olds and 6.42 +/- 0.69 ml in 14-year olds. Iodine excretion (143.8 [4.1-984.8] micrograms iodine/g creatinine) indicated adequate iodine supply to the tested subjects. South Tyrol is thus, according to WHO criteria, no longer an endemic goitre area. The voluntary use of iodinated cooking salt and changed food habits have probably effected this change in goitre epidemiology.