Trend of Iodine Status in the Eastern Mediterranean Region and Impact of the Universal Salt Iodization Programs: a Narrative Review

Indirect reference intervals for TSH in a sample of lebanese pregnant women

Background

Thyroid dysfunction in pregnant women can lead to fetal complications. Thyroid-stimulating hormone (TSH) is the key hormone for diagnosis of thyroid dysfunction. No previous study has established reference intervals (RI) for TSH in Lebanese pregnant women. The objective of this study is to define the TSH RIs for each trimester of pregnancy in healthy Lebanese pregnant women using an indirect method.

Materials and methods

This retrospective study included 287 pregnancies selected from the records of an obstetric clinic at Hôtel-Dieu de France University Hospital from January 2021 to May 2023. A control group of 103 non-pregnant women was also included in the study. The collected TSH values were stratified by trimester (first and second) of pregnancy and postpartum. After applying the exclusion criteria, a total of 458 TSH values were included in the analysis.

Results

The respective medians and RIs for TSH during the first, second pregnancy trimesters and postpartum are 1.57 (0.43-3.20 mIU/L), 1.84 (0.56-4.41 mIU/L), and 1.38 (0.30-3.60 mIU/L), while for the control group it is 1.66 (0.64-4.24 mIU/L). There is a significant correlation between TSH values in the first trimester and those in the second trimester and postpartum (p ≤ 0.001 and p = 0.002 respectively). No significant correlation was observed between age and TSH levels in the first and second trimesters and as well as in postpartum.

Conclusion

Our RIs are close to the revised American Thyroid Association (ATA) recommendations. Further research is needed to understand the mechanisms and clinical impact of these differences.

Global Perspectives on China's Lodine Dietary Reference Intakes: Revisions, Public Health Implications, and Future Strategies

Iodine is an essential trace element for the human body and a fundamental precursor for the synthesis of thyroid hormones, playing a critical role in maintaining thyroid function. Because iodine cannot be synthesized by the body, it must be obtained from external sources. The development of dietary reference intakes for iodine has evolved over time, with various countries establishing guidelines based on local dietary surveys, iodine status assessments, and health outcomes. The dietary reference intakes of iodine vary widely across different regions due to differences in dietary habits, food fortification policies, and iodine supplementation practices. This review primarily synthesizes and analyzes the latest research data on iodine intake reference values set by China and compares these values with those established by other countries and organizations. Additionally, this review examines primary dietary sources of iodine, such as iodized salt, dairy products, and seafood, and discusses challenges posed by public health initiatives like salt-reduction campaigns that may impact overall iodine intake. Furthermore, it highlights current global trends in iodine nutrition while emphasizing countries where iodine intake is classified as sufficient, deficient, or excessive. By comparing iodine intake recommendations worldwide, this review aims to provide a comprehensive understanding of iodine nutrition and its impact on public health. It also identifies gaps in current research and offers insights into future directions for ensuring optimal iodine intake through updated guidelines and public health interventions.

Reference intervals for thyroid-stimulating hormone in the adult Lebanese population: Results from the last decade

Background

Thyroid Stimulating Hormone (TSH) is the most accurate marker in the assessment of thyroid function. Establishing a reference interval (RI) for TSH is essential for interpreting results of thyroid function tests. TSH RI in the Lebanese population using the indirect method is lacking. The aim of this study is to establish TSH RI according to age and gender, and to assess its trend over the last decade using the indirect method.

Methods

TSH values of 80156 outpatient subjects (age range 18-99) were retrospectively collected between January 2011 and April 2021 from a tertiary university medical center in Beirut. TSH was measured using the same chemiluminescent assay (Immulite 2000).

Results

The median TSH was 1.4 mIU/L (IQ 0.94-2.10). TSH RI was wider compared to the manufacturer one (0.31-4.95 mIU/L vs 0.40-4.0, p < 0.001). There was a decrease in lower reference limit (LRL) and an increase in upper reference limit (URL) with the increase in age categories (p < 0.001 for both comparisons). RI was broader in women compared to men (respectively 0.29-5.20 vs 0.35-4.48 mIU/L, p < 0.001). There are significant differences in the median, LRL and URL across the years and in all age categories (p < 0.001). TSH RI using the indirect method was wider than the direct method one (p < 0.001).

Conclusion

Using the indirect method, TSH RI in the Lebanese population is wider than the manufacturers'one and that those obtained by the direct method and varies according to age, gender and over time. A periodic reevaluation of RI for each population should be done.

The burden of iodine deficiency

Introduction

Iodine deficiency is a global issue; however, no comparable assessments of the burden of iodine deficiency have been conducted worldwide. Hence, we measured the estimated annual percentage changes (EAPCs) from 1990 to 2019. Our aim was to quantify the geographic differences in the burden of iodine deficiency worldwide.

Material and methods

The Global Burden of Diseases, Injuries, and Risk Factors Study 2019 methodology was employed to investigate the worldwide, regional, and national incidence of iodine deficiency and the accompanying disability-adjusted life years (DALYs).

Results

The global age-standardized incidence (ASI) and DALY rates of iodine deficiency declined from 1990 to 2019, with an EAPC of -0.44 and -1.35, respectively. Low and low-middle SDI had much higher ASI and DALY rates of iodine deficiency than other SDI regions. At the regional level, the largest growth in the ASI rate of iodine insufficiency from 1990 to 2019 occurred in East Asia, and at the national level, the greatest increases in the ASI rate of iodine deficiency occurred in the Philippines, Pakistan and Nepal. In addition, males had a lower worldwide ASI rate of iodine insufficiency than females did, with the incidence rate peaking in populations aged 20-24.

Conclusions

Between 1990 and 2019, there was a decline in the global ASI and DALY rates of iodine deficiency. However, East Asia, the Philippines, Pakistan and Nepal exhibited the largest increases in the ASI rates of iodine deficiency, demonstrating their significant burden of iodine insufficiency. These regions must therefore be targeted for intervention.

Analysis of the nutritional status in the Palestinian territory: a review study

Background

Food insecurity, occupation, and poverty contribute to the poor nutritional status of Palestine. This review study aimed to analyze the nutritional status in the Palestinian Territory by analyzing published data from 2011 to 2023.

Method

Searching for relevant publications yielded 67 studies. Based on reviewing these studies, five major themes were identified: low birth weight, breastfeeding, obesity and overweight, protein-energy malnutrition, and micronutrient deficiency.

Results

Based on the review of these studies, five major themes were identified, namely, low birth weight, breastfeeding, obesity and overweight, protein-energy malnutrition, and micronutrient deficiency. Based on the literature, the prevalence rate of exclusive breastfeeding was 24.4% in the Gaza Strip, compared to a national rate of 39.9% in 2020. Smoking, anemia in mothers, diet during pregnancy, and indoor pollution were associated with low birth weight. One-fifth of the boys and girls were stunted by 2 years of age in the Gaza Strip, and girls were more stunted than boys. The prevalence rates of underweight, overweight, and obesity among school children in the West Bank were 7.3%, 14.5%, and 15.7%, respectively. Age, gender, and living area were significant predictors of being overweight among school children. The prevalence rates of overweight and obesity among adults in Palestine were 57.8% and 26.8%, respectively. Obesity is associated with a family history, chronic diseases, and low physical activity among adults. Exclusive breastfeeding was below the WHO recommendations, while significant rates of obesity and overweight were found among children and adults. Iron-deficiency anemia (IDA) among pregnant women and children remains a challenging public health issue, while other micronutrient deficiencies are high among children.

Conclusion

This review emphasizes the need for multi-sectoral interventions to address malnutrition and nutritional shifts. It identifies gaps and addresses nutrition-related issues in the Palestinian Territory, which can serve as a basis for guiding United Nations agencies and governments in formulating evidence-based policies and strategies for prioritizing nutritional interventions to meet sustainable development goals.

Adequacy of Iodine Status and Associations with Gut Health: A Prospective Cohort Study among Infants in 8 Low- and Middle-Income Countries

BACKGROUND

Environmental enteric dysfunction increases the likelihood of micronutrient deficiencies among infants, but few studies have assessed the potential impact of gut health on urinary iodine concentration (UIC) among this vulnerable group.

OBJECTIVES

We describe the trends of iodine status among infants from 6 to 24 mo old and examine the associations between intestinal permeability, inflammation, and UIC from 6 to 15 mo of age.

METHODS

Data from 1557 children enrolled in this birth cohort study conducted in 8 sites were included in these analyses. UIC was measured at 6, 15, and 24 mo of age by using the Sandell-Kolthoff technique. Gut inflammation and permeability were assessed using the concentrations of fecal neopterin (NEO), myeloperoxidase (MPO) and alpha-1-antitrypsin (AAT), and lactulose-mannitol ratio (LM). A multinomial regression analysis was used to assess the classified UIC (deficiency or excess). Linear mixed regression was used to test the effect of interactions among biomarkers on logUIC.

RESULTS

All studied populations had adequate (≥100 μg/L) to excess (≥371 μg/L) median UIC at 6 mo. Between 6 and 24 mo, 5 sites displayed a significant decline in the infant's median UIC. However, median UIC remained within the optimal range. An increase of NEO and MPO concentrations by +1 unit in ln scale reduced the risk of low UIC by 0.87 (95% CI: 0.78-0.97) and 0.86 (95% CI: 0.77-0.95), respectively. AAT moderated the association between NEO and UIC (P < 0.0001). The shape of this association appears to be asymmetric and in a reverse J-shape, with a higher UIC observed at both lower NEO and AAT concentrations.

CONCLUSIONS

Excess UIC was frequent at 6 mo and tended to normalize at 24 mo. Aspects of gut inflammation and increased permeability appear to reduce the prevalence of low UIC in children aged 6 to 15 mo. Programs addressing iodine-related health should consider the role of gut permeability in vulnerable individuals.

Nutrition Profile for Countries of the Eastern Mediterranean Region with Different Income Levels: An Analytical Review

The World Health Organization's (WHO) Eastern Mediterranean Region (EMR) is suffering from a double burden of malnutrition in which undernutrition coexists with rising rates of overweight and obesity. Although the countries of the EMR vary greatly in terms of income level, living conditions and health challenges, the nutrition status is often discussed only by using either regional or country-specific estimates. This analytical review studies the nutrition situation of the EMR during the past 20 years by dividing the region into four groups based on their income level-the low-income group (Afghanistan, Somalia, Sudan, Syria, and Yemen), the lower-middle-income group (Djibouti, Egypt, Iran, Morocco, Pakistan, Palestine, and Tunisia), the upper-middle-income group (Iraq, Jordan, Lebanon, and Libya) and the high-income group (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and United Arab Emirates)-and by comparing and describing the estimates of the most important nutrition indicators, including stunting, wasting, overweight, obesity, anaemia, and early initiation and exclusive breastfeeding. The findings reveal that the trends of stunting and wasting were decreasing in all EMR income groups, while the percentages of overweight and obesity predominantly increased in all age groups across the income groups, with the only exception in the low-income group where a decreasing trend among children under five years existed. The income level was directly associated with the prevalence rates of overweight and obesity among other age groups except children under five, while an inverse association was observed regarding stunting and anaemia. Upper-middle-income country group showed the highest prevalence rate of overweight among children under five. Most countries of the EMR revealed below-desired rates of early initiation and exclusive breastfeeding. Changes in dietary patterns, nutrition transition, global and local crises, and nutrition policies are among the major explanatory factors for the findings. The scarcity of updated data remains a challenge in the region. Countries need support in filling the data gaps and implementing recommended policies and programmes to address the double burden of malnutrition.

Barriers, Enablers, and Perceptions on Dietary Salt Reduction in the Out-of-Home Sectors: A Scoping Review

In this review, we have investigated the perceptions, barriers, and enabling factors that were responsible for a dietary salt reduction in the out-of-home sectors. For this purpose, we examined different knowledge databases such as Google Scholar, Ebscohost, MEDLINE (PubMed), Ovid, and Cochrane Library for research articles from September to December 2020. The inclusion criteria for the research articles were that they had to be published in English and had to be a qualitative or quantitative study that was conducted after 2010. These studies also had to report the various enablers, barriers, and perceptions regarding salt reduction in the out-of-home sectors. After implementing the inclusion criteria, we successfully screened a total of 440 studies, out of which 65 articles fulfilled all the criteria. The perceived barriers that hindered salt reduction among the out-of-home sectors included lack of menu and food variabilities, loss of sales due to salt reduction, lack of technical skills for implementing the salt reduction processes for cooking or reformulation, and an absence of environmental and systemic support for reducing the salt concentration. Furthermore, the enablers for salt reduction included the intervention programs, easy accessibility to salt substitutes, salt intake measurement, educational availability, and a gradual reduction in the salt levels. With regards to the behavior or perceptions, the effect of organizational and individual characteristics on their salt intake were reported. The majority of the people were not aware of their salt intake or the effect of salt on their health. These people also believed that low salt food was recognized as tasteless. In conclusion, the enablers, barriers, and perceptions regarding salt reduction in the out-of-home sectors were multifaceted. Therefore, for the implementation of the strategies, policies, and initiatives for addressing the barriers, the policymakers need to encourage a multisectoral collaboration for reducing the salt intake in the population.

Assessment of the Impact of Salt Iodisation Programmes on Urinary Iodine Concentrations and Goitre Rates: A Systematic Review

Introduction

Two main strategies are currently recommended for the prevention and control of iodine deficiency in the world: implementation of universal salt iodisation programmes and permanent monitoring of iodine consumption by the population. Although iodine intake and coverage iodised salt have increased in the world population, iodine deficiency disorders (IDDs) may still be a public health problem in a few countries or communities.

Objective

To assess the impact of salt iodisation programmes on urinary iodine concentrations and goitre rates in the world population. Methodology. A systematic review based on the PRISMA method. We obtained articles from Scopus, Science Direct, MEDLINE databases, and other sources between March and April 2020, without limitation of dates. "Iodisation" AND "urinary iodine concentrations" AND "goitre" in English, Portuguese, and Spanish without filters and clinical trial, case-control, and cross-sectional studies were included in this review.

Results

Of 479 abstracts, twenty-three were eligible. Coverage on iodised salt was in the range of 16 to 98%, and 11 studies had been sufficient, whilst eight studies had adequate iodine concentration in salt and three excess. 81.8% of studies that had an adequate median of UIC had a good impact in their respective salt iodisation programmes.

Conclusion

After 18 years of salt iodisation programme implementation in the 13 countries, the majority achieved sustaining elimination of IDD whilst all had adequate median UIC; however, more detailed studies are still needed to confirm that all communities are equally protected of IDD.