Iodine supplementation in Austria: methods and results.

Area of Science:

• Endocrinology
• Public Health
• Nutritional Science

Background:

• Austria historically faced severe iodine deficiency, leading to high goiter rates.
• Mandatory salt iodination was implemented in 1963 to address this public health issue.
• Initial salt iodination levels proved insufficient, necessitating adjustments in 1990.

Purpose of the Study:

• To evaluate the long-term impact of salt iodination on iodine status and thyroid health in Austria.
• To assess goiter prevalence, urinary iodine excretion, and thyroid autoantibody levels in different age groups.
• To investigate changes in hyperthyroidism and thyroid cancer histology following salt iodination policies.

Main Methods:

• Longitudinal monitoring of urinary iodine excretion and goiter prevalence in schoolchildren.
• Cross-sectional study in 2000 of 430 adults in Carinthia, assessing iodine intake, goiter, and thyroid autoantibodies.
• Analysis of historical data and comparison of prevalence rates before and after iodination policy changes.

Main Results:

• Increased salt iodination in 1990 significantly improved iodine status and reduced goiter prevalence in younger populations.
• Despite sufficient iodine supply, elderly individuals who experienced prolonged deficiency still exhibit high goiter rates.
• Thyroid autoantibody prevalence normalized to levels seen in iodine-sufficient regions, but hyperthyroidism and autoimmune thyroid diseases increased.

Conclusions:

• Salt iodination effectively improved iodine supply and reduced goiter in Austria, particularly for those born after 1963.
• Increased iodine intake is associated with a rise in hyperthyroidism and autoimmune thyroid diseases.
• Salt iodination has influenced thyroid cancer histology and necessitates ongoing public health monitoring.