Age- and gender-related variations in the prevalence of goiter among schoolchildren from Gorgan a decade after universal salt iodization

The present study was conducted after 10 years of Universal Salt Iodization (USI) in Iran, to assess goiter prevalence in Gorgan.

From April to June 2003, 1400 (500 female and 900 male) children aged 7-11 years, from 12 randomly selected schools in Gorgan, were enrolled for goiter assessment by palpation. Morning spot samples were obtained from 101 female and 82 male children for urinary iodine concentration (UIC) by digestion method.

Goiter was detected in 370 (26. 4%), 173 (34. 6%) female, and 197 (21. 9%) male children. Goiter rates in 9, 10, and 11-year females were 31, 37, and 52%, which were higher than those seen in males, of the same age, being 17. 2, 20, and 23. 3% (p values < 0. 012, < 0. 003, and < 0. 0001), respectively. The greatest odds ratio (95% confidence interval [95%CI]) was obtained in 11 year-old children (odds ratio 4. 7, 95%CI 2. 71-8.). Median (range 95%CI) UIC level in children was 190 (20-600, 190-230) µg/L. Corresponding values in males were 220 (30-590, 212-261) µg/L and in females were 170 (20-600, 190-230) µg/L, respectively (p = 0. 001). UIC < 50 and < 100 µg/L was present in 4 (2. 2%) and 16 (8.7%) goitrous children. UIC < 100 µg/L was more prevalent in 10-11 year-old girls than in boys of the same age (p=0.02) or in younger girls (p = 0. 03). Among goitrous children, 86 (47%) had UIC ≥ 200 µg/L. Nine (22%) of 10-11 year-old goitrous females had UIC < 100 µg/L.

According to UIC values, Gorgan is considered an iodine sufficient area, but it seems that some 10-11 year old females are at risk low iodine intake. Assessment of goiter, iodine intake, and hormonal changes in adolescents are recommended.