Relationship between water iodine and children's goiters

Area of Science:

• Endocrinology
• Public Health
• Environmental Health

Background:

• Excessive iodine intake is linked to goiter development.
• The precise relationship between water iodine concentration (WIC) and goiter rate (GR) in children remains unclear, particularly in high-iodine regions.
• Understanding these factors is critical for public health interventions.

Purpose of the Study:

• To investigate factors influencing children's goiter rate (GR) in areas with high water iodine concentration (WIC).
• To determine the threshold of WIC associated with an increased GR.
• To analyze the impact of non-iodised salt coverage rate (NISCR) on GR.

Main Methods:

• A large-scale study involving 54,050 children from eight high WIC provinces in China (2018-2020).
• Collection of drinking water, urine, and edible salt samples.
• Measurement of thyroid volume (Tvol) and analysis using a generalized additive model (GAM).

Main Results:

• The overall GR was 3.34%, with median WIC at 127.0 µg/l and median urinary iodine at 318 µg/l.
• Water iodine and urinary iodine levels significantly influence Tvol and GR.
• GR increased rapidly when WIC exceeded 420 µg/l or urinary iodine exceeded 800 µg/l.
• A NISCR above 85% was associated with the lowest GR.

Conclusions:

• High WIC, specifically above 420 µg/l, may elevate the risk of goiter in children.
• Increasing NISCR to over 85% is a key strategy to mitigate goiter risk in high WIC areas.
• Public health strategies should focus on managing both water iodine levels and salt iodisation practices.