ESPE Yearbook of Paediatric Endocrinology

Brief Summary: This prevalence study examined global, regional and national trends in iodine deficiency among adolescents and young adults, based on data from the Global Burden of Disease (GBD) 2019 database.

Iodine deficiency is a significant public health concern as it can result in hypothyroidism, goiter, and alterations in growth and development. While universal salt iodination has had a significant impact, there is a need for better estimates of the prevalence to guide government strategies and preventive research. The GBD 2019 database was developed by the World Health Organization (WHO) and World Bank and includes information from 204 countries with data on the global burden of 369 diseases and injuries. Countries are divided into six regions including Africa, Eastern Mediterranean, Europe, the Americas, Southeast Asia, and the Western Pacific, and then also divided into five sociodemographic index (SDI) quintiles.

Analysis of global trends reveals that from 1990 to 2019, there was a significant global decline in iodine deficiency prevalence among adolescents. The rates reduced from 3,082 per 100,000 individuals in 1990 to 2,190 per 100,000 in 2019, likely due to implementation of Universal Salt Iodination (USI) in countries with previously high rates of deficiency. The Disability-Adjusted Life Year (DALY) rate for iodine deficiency also decreased globally, indicating overall improvement in the public health impact of iodine deficiency. In 1990, Southeast Asia had the highest prevalence of iodine deficiency, but by 2019, Africa had taken over. Southeast Asia saw the most rapid decline in prevalence rates. The Eastern Mediterranean was the only region where the prevalence of iodine deficiency increased. Analyses by age and sex found that young adults (aged 20–24) accounted for most cases of iodine deficiency in 2019. Both male and female adolescents saw a significant decrease in iodine deficiency rates from 1990 to 2019. Low-SDI countries had the highest prevalence and DALY rates.

Although there has been a substantial global decline in the burden of iodine deficiency among adolescents, it remains a major health concern in low-SDI countries. Evidence from individual countries, including Democratic Republic of Congo, India and China, indicates that implementation of USI has had a significant impact, although this is dependent on the utilization of iodized salt by individual households. The authors recommend continued efforts to strengthen monitoring systems and encourage implementation of effective iodine supplementation measures, particularly in the most affected regions.

References: 1. Milevska-Kostova N et al (2022) Universal salt iodization potentially contributes to health equity: socio-economic status of children does not affect iodine status. J Pediatr Endocrinol Metab 35(9):1154–1160.2. GBD 2019 Diseases and Injuries Collaborators (2020) Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet 396(10258):1204–1222