Iodine status and thyroid function among Spanish schoolchildren aged 6-7 years: the Tirokid study

Area of Science:

• Pediatric Endocrinology
• Nutritional Science
• Public Health

Background:

• Iodine deficiency remains a global health concern, particularly affecting children.
• No prior nationwide study assessed iodine status in Spanish children.
• Schoolchildren aged 6-7 years are a vulnerable group for iodine deficiency disorders.

Purpose of the Study:

• To evaluate iodine status and thyroid function in Spanish schoolchildren aged 6-7 years.
• To identify factors associated with iodine status, including dietary intake.
• To assess the prevalence of thyroid dysfunction indicators.

Main Methods:

• An observational, multicentre, cross-sectional study was conducted.
• Median urinary iodine (UI) and whole blood thyroid-stimulating hormone (TSH) levels were measured.
• A Food Frequency Questionnaire (FFQ) assessed iodine-rich food consumption.

Main Results:

• The median UI was 173 μg/l, indicating adequate iodine intake in Spanish schoolchildren.
• 17.9% of children had UI < 100 μg/l, and 7.6% had TSH levels above reference values.
• Iodized salt consumption and dairy intake were associated with higher UI; median TSH was higher in females and those with a family history of hypothyroidism.

Conclusions:

• Spanish schoolchildren generally have adequate iodine intake.
• A notable prevalence of elevated TSH levels was observed, warranting further investigation.
• The association between elevated TSH and thyroid autoimmunity requires further assessment in this population.