Thyroid Gland Volume and Urinary Iodine Excretion in Children 6-11 Years Old in an Endemic Area

Abstract

Goiter prevalence and urinary iodine excretion levels were assessed in 605 schoolchildren (301 males and 304 females), aged 6-11 years, living in the Antalya region, a well known endemic goiter area in Turkey. Goiter prevalence was evaluated by clinical examination and ultrasound of the thyroid gland. Urinary iodine levels were expressed as microg/g creatinine. Goiter by inspection and palpation was found in 35% (n = 212) of all subjects, in 37.5% (n = 114) of girls and 32.5% (n = 98) of boys. Iodine deficiency of moderate degree was detected from the point of goiter prevalence. With regard to the upper limits of reference thyroid volumes reported by WHO and ICCIDD, goiter by ultrasonography was found in 34% (n = 206) of all subjects, in 36.8% (n = 112) of girls and 31% (n = 94) of boys. Median iodine/creatinine ratios of all subjects, and goitrous and non-goitrous subjects, were 64.1+/-20.1, 62.8+/-21.8 and 64.9+/-19.1 microg/g, respectively. Urinary iodine excretion levels revealed mild iodine deficiency in the region. No significant correlation was observed between urinary iodine excretion levels and thyroid volumes (r = 0.12, p>0.05). Iodine deficiency of mild to moderate degree in schoolchildren aged 6-11 years was detected in Antalya. It was concluded that urgent measures must be undertaken to eradicate iodine deficiency in the region.

Screening of Parents and Siblings of Patients with Thyroid Dysgenesis by Thyroid Function Tests and Ultrasound

“…Age-specific normal values for thyroid volumes vary with the iodine status and ethnicity of the population [11,12,13,14,15]. These previous studies, establishing reference ranges for thyroid volumes, usually describe upper limits (for diagnosis of goiter) but omitted lower limits [11,12,13,14,15].…”

Sensitivity of Iodine Deficiency Indicators and Iodine Status in Turkey

“…A high incidence of neonatal hypothyroxinemia has been reported in endemic areas 12 ' 14 . 17 . In addition to these endemic iodine deficiency indicators, we also used FT4, Tg, and height percentiles to define endemic iodine deficiency.…”

Goiter Prevalence and Urinary Iodine Concentration in Slovenian Adolescents

“…When an individual's urinary iodine concentration was compared to their thyroid volume, no significant correlation was found. It was previously documented that random urinary iodine concentration and individuals thyroid volume do not correlate (15,19). This is most probably the consequence of the fact that there is an intra-and interday variability of urinary iodine concentration in an individual (20,21).…”