Goiter prevalence and urinary iodine status in urban and rural/mountain areas of Piedmont region

Abstract

Piedmont region was reported in the 70s as a mild iodine-deficient area with a goiter prevalence > 10%. This study aimed at characterizing the current status of iodine deficiency in Piedmont, with special attention to putative differences between urban and rural/mountain areas. A cross-sectional, observational study was performed according to the surveillance methods for iodine deficiency disorders recommended by the World Health Organization (WHO). Ultrasound local thyroid volume reference values and median urinary iodine concentration were obtained in 2178 schoolchildren aged 11-15 yr, resident in Piedmont region for more than 5 yr to assess both goiter prevalence and iodine intake. Anamnestic and anthropometric data, thyroid volume by both bimanual palpation and ultrasound were assessed, and spot urinary iodine samples were collected. The median urinary iodine concentration was 115.8 microg/l and the prevalence of goiter 3.1%, indicating this area as iodine-sufficient. Nevertheless, 39% of the schoolchild population had urinary iodine levels < 100 microg/l and 6.8% < 50 microg/l. No differences in goiter prevalence and median urinary iodine excretion were observed between urban and rural/ mountain populations. In conclusion, Piedmont is now an iodine-sufficient region. As no programs of salt iodization have been carried out in the last 30 yr, a silent iodine replacement has occurred. Despite a sufficient median urinary iodine excretion, a program of iodine prophylaxis is strongly recommended due to a large part of iodine-deficient population.