Partial beneficial effects of the so called "silent iodine prophylaxis" on iodine deficiency disorders (IDD) in northeastern Sicily endemia.

The prevalence of goiter among schoolchildren and the daily urinary iodine excretion in the general population were evaluated in 4 municipalities in the endemic goiter area in Northeastern Sicily in two different surveys. The first, carried out in 1977-1978, covered 2,493 (91%) schoolchildren; the second, in 1987-1988, covered 2,167 (92%) schoolchildren. A dramatic decrease in goiter prevalence was apparent in each community as follows: in Castell'Umberto (3,904 inhabitants, altitude 641/750 m above sea level) goiter prevalence (G) decreased from 79.7% to 44.2% with a percent reduction (%r) of 44.5 and an increase in 24-h urinary iodine excretion (UIE) from 22.3 +/- 16.4 micrograms/24 h (n = 30) to 48.7 +/- 43.4 (n = 50). A similar trend was apparent in Tortorici (10,194 inhabitants, 475/700 m) where G decreased from 62.2 to 26.5% (% r 57.4) with a UIE increase from 28.4 +/- 29.6 (n = 35) to 47.6 +/- 59.3 (n = 40); in Sinagra (3,387 inhabitants, 300 m) where G decreased from 61.6 to 32.7% (% r 46.9) and UIE increased from 26.0 +/- 21.1 (n = 25) to 66.6 +/- 69.6 (n = 102) and in Sant'Angelo di Brolo (5,732 inhabitants, 380 m) where G decreased from 48.7 to 27.5% (% r 43.5) and UIE increased from 26.3 +/- 16.7 (n = 30) to 47.7 +/- 73.8 (n = 34). These events are clearly related and certainly dependent on the changed alimentary habits in the area due to the improved distribution of frozen food and industrially prepared dairy products, eventually enriched by iodine.(ABSTRACT TRUNCATED AT 250 WORDS)