Article révisé par les pairs
Résumé : The paper describes the epidemiology of goiter in two endemic areas of the highlands of north-eastern Sicily and evaluates the respective roles of iodine deficiency and high thiocyanate (SCN) supply in the etiology of the disease. One endemic area comprises Troina and Bronte and the other San Angelo. Control investigations were conducted in three non goitrous urban districts (Catania and Messina in Sicily and Brussels in Belgium). The prevalence of goiter determined in 4427 schoolchildren was 55.0% in Troina, 42.0% in Bronte and 48.7% in San Angelo. In Brussels, 24 h 131I thyroidal uptake was 49.4±2.3% (SE), and daily urinary excretion of iodine (I) and SCN were 51.2±5.8 μg/day and 6.7±1.3 mg/day, respectively. In the endemic area of San Angelo, predictably, high uptake (70.1±2.5%, p<0.001) was associated with abnormally low iodine excretion (26.3±1.7 μg/day, p< 0.001). SCN excretion was normal (7.7±0.3 mg/day, p > 0.2). By contrast, in Troina and Bronte, uptake was similar to the value obtained in Brussels (50.8±2.4%, p > 0.5), iodine excretion was slightly but not significantly lower (40.7±2.6 μg/day and 43.2±4.9 μg/day, respectively, p > 0.2) but SCN excretion was substantially increased (11.0±0.7 mg/day, p < 0.02 and 15.2±1.5 mg/day, p < 0.005, respectively). The daily urinary l/SCN ratios were similar in the three non goitrous districts (7.8, 8.7 and 9.1 for Brussels, Catania and Messina, respectively). The corresponding values were much lower in the goitrous areas (3.7, 2.8 and 3.4 for Troina, Bronte and San Angelo, respectively). The serum levels of thyroxine, triiodothyronine and thyrotropin were within the normal range in both endemic areas. These observations show that severe endemic goiter in Sicily may be related either to iodine deficiency or to increased SCN levels associated with a borderline iodine intake: the balance between I and SCN supplies thus appears to be the determining factor in the etiology of the disease in the regions considered. SCN has well established antithyroid properties. Its origin could be cabbage, which is a staple food in this region. © 1978, Italian Society of Endocrinology (SIE). All rights reserved.