Excessive iodine intake and thyroid dysfunction among lactating Saharawi women

Area of Science:

• Endocrinology
• Nutritional Science
• Public Health

Background:

• Excessive iodine intake can cause thyroid dysfunction, posing risks during pregnancy and lactation.
• Assessing iodine status and thyroid health in lactating women is crucial, especially in areas with high environmental iodine levels.

Purpose of the Study:

• To evaluate iodine status and the prevalence of thyroid dysfunction among lactating women in areas with high (HI) and very high iodine (VHI) concentrations in drinking water.
• To investigate the relationship between iodine intake, iodine status markers, and thyroid function in this population.

Main Methods:

• A cross-sectional survey involving 111 lactating women in the Saharawi refugee camps, Algeria.
• Measurement of breast milk iodine concentration (BMIC), urinary iodine concentration (UIC), and iodine content in food and drinks.
• Assessment of thyroid hormones, antibodies, and body mass index (BMI); estimation of iodine intake via 24-hour dietary recall.

Main Results:

• Median UIC, BMIC, and iodine intake were high (350 μg/L, 479 μg/L, and 407 μg/day, respectively).
• Higher UIC and BMIC were associated with living in a VHI area and higher iodine intake.
• Thyroid dysfunction or positive thyroid antibodies affected 33.3% of women, with no significant difference between HI and VHI areas. BMI, BMIC, and elevated thyroglobulin predicted abnormal thyroid function.

Conclusions:

• The high prevalence of thyroid dysfunction in this cohort is likely attributable to prolonged excessive iodine intake.
• Findings highlight the potential public health implications of high environmental iodine exposure on thyroid health in lactating women.