Global, Regional, and National Burden of Iodine Deficiency in Reproductive Women From 1990 to 2019, and Projections to 2035: A Systematic Analysis for the Global Burden of Disease Study in 2019

Abstract

Background: Iodine deficiency threatens women of reproductive-age (15-49 years) worldwide, increasing risks of thyroid dysfunction and developmental abnormalities. Accurate trend prediction is essential for targeted prevention strategies.

Purpose: To investigates the global, regional, and national disease burden of iodine deficiency among reproductive-age women from 1990 to 2019, as well as projected trends through 2035.

Patients and methods: Using Global Burden of Disease 2019 data, we assessed prevalence, mortality, years lived with disability (YLDs), and disability-adjusted life years (DALYs) across 204 countries/territories (1990-2019). Age-period-cohort Bayesian model was used to predict trends from 2020 to 2035.

Results: In 2019, 81.4 million women of reproductive age globally had iodine deficiency (age-standardized prevalence: 2871.7/100,000), reflecting a 13.3% reduction since 1990. The condition caused 1.1 million YLDs (age-standardized rate: 38.4/100,000), marking a 27.4% decrease from 1990. Projections suggest sustained declines through 2035. Notably, a strong inverse correlation emerged between Socio-demographic Index (SDI) and disease burden, with a correlation coefficient of -0.58 (95% CI: -0.63 to -0.53, p<0.001). Geographically, the highest burden clustered in Central Sub-Saharan Africa, South Asia, and Eastern Sub-Saharan Africa, with Somalia, the Democratic Republic of the Congo, and Congo having the highest national prevalence.

Conclusion: The global burden of iodine deficiency among women of reproductive age has decreased substantially since 1990. Nonetheless, considerable challenges persist in lower SDI regions, especially affecting women within the reproductive age. Addressing these inequities in global iodine nutrition and alleviate the iodine deficiency-related burden, targeted implementation strategies and continuous monitoring measures are urgently needed.

Keywords: iodine deficiency; prevalence; women of reproductive age; years lived with disability.

Figure 1

Global age-standardized point prevalence of iodine deficiency among women of reproductive age per 100,000 population in 2019.

Figure 2

Global age-standardized point YLDs rates of iodine deficiency among women of reproductive age per 100,000 population in 2019.

Figure 3

Global number of cases and rates of iodine deficiency among female per 100,000 population in 2019. Lines indicate prevalent case with 95% uncertainty intervals for female. (A) Global number of prevalent cases and prevalence of reproductive age. (B) Global number of prevalent cases and prevalence of all age groups. (C) Global number of YLDs cases and YLDs rate of reproductive age. (D) Global number of YLDs cases and YLDs rate of all age groups.

Figure 4

Age-standardized YLDs rates of iodine deficiency among women of reproductive age for the 21 Global Burden of Disease regions by sociodemographic index, 1990–2019. Thirty points are plotted for each region and show the observed age standardized YLDs rates from 1990 to 2019 for that region. Expected values, based on sociodemographic index and disease rates in all locations, are shown as a solid line. Regions above the solid line represent a higher-than-expected burden and regions below the line show a lower-than-expected burden.

Figure 5

Trends in global iodine deficiency among women of reproductive age burden from 1990 to 2035. (A) Number of prevalent cases. (B) Number of YLDs cases. (C) Age-standardized prevalent rate. (D) Age-standardized YLDs rate.