Iodine deficiency disorders in India.

Area of Science:

• Public Health
• Endocrinology
• Nutrition Science

Background:

• Iodine deficiency disorders (IDDs) were historically widespread across the Indian subcontinent.
• Successful salt iodisation programs led to a significant reduction in goitre prevalence and improved iodine nutrition.
• Despite widespread salt iodisation, goitre remains endemic in certain populations, particularly among school children.

Purpose of the Study:

• To assess the long-term impact of salt iodisation on goitre prevalence in India.
• To investigate the reasons for the persistence of goitre in school children despite adequate salt iodisation.
• To explore potential alternative factors contributing to thyroid dysfunction in the studied population.

Main Methods:

• Review of epidemiological data on goitre prevalence before and after salt iodisation.
• Community-based surveys assessing iodine nutrition status and thyroid function.
• Investigation into potential environmental or autoimmune factors influencing thyroid health.

Main Results:

• A remarkable decline in overall goitre prevalence and normalization of iodine status were observed post-iodisation.
• Persistent goitre endemicity was noted in a segment of school children even a decade after the implementation of salt iodisation.
• High levels of thiocyanate exposure and prevalence of autoimmune thyroid disease were identified as potential contributing factors.

Conclusions:

• Salt iodisation has been highly effective in controlling widespread iodine deficiency disorders in India.
• The persistence of goitre in some school children highlights the need to investigate other etiological factors beyond iodine deficiency.
• Further research into environmental exposures like thiocyanates and the role of autoimmune thyroid disease is warranted to fully address thyroid health in the community.