Endemic goiter with iodine sufficiency: a possible role for the consumption of pearl millet in the etiology of endemic goiter

Does consumption of pearl millet cause goiter? A systematic review of existing evidence

Millets (defined here to also include sorghum) have been consumed in Asian and African countries for centuries, and have in recent years become increasingly popular in Western countries, especially because of their proven health and environmental benefits. Nevertheless, some concerns have been raised that their consumption can interfere with thyroid function and cause goiter. This systematic review aimed to investigate the link between millet consumption and goiter. We found nine papers that were relevant to this topic and included them in this review. Among nine papers eight were on pearl millet and one was on fonio millet. The findings of the review indicate that published literature on the association of pearl millet and increased goiter prevalence are not compelling and strong enough to assert that pearl millet consumed as part of a balanced diet can lead to goiter in the general population. To ensure appropriate factual messaging about millets, we need more scientific research to conclusively state whether millet consumption mediates goitrogenic effects.

Assessment of Red Cell Distribution Width among Sudanese Patients with Hypothyroidism.. [DOI: 10.21203/rs.3.rs-2518318/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: Thyroid dysfunction has a strong linkage with anemia. RDW was traditionally regarded as a part of routine evaluation of anemia Elevated RDW level was significantly associated with subclinical hypothyroidism and hypothyroidism. Objectives: The aim of this is study to assess the Red Cell Distribution Width (RDW-CV and RDW-SD) in patients with hypothyroidism. Methodology: This is a case-control laboratory-based study conducted among 50 patients with hypothyroidism as cases (38.50 ± 10.46 years; 36% males and 64% females) and 50 normal healthy individuals as controls (35.52 ± 11.64 years; 46% males and 54% females) in National Cancer Institute – University of Gezira (NCI-UG), Gezira State, Sudan from January to October 2020. Three ml of venous blood sample was collected in an EDTA container. Red cell parameters (RBC count, MCV, RDW-CV, and RDW-SD) were measured using Sysmex XP 300 Cell Counter. SPSS computer program (v 22.0) was used for data analysis. Results: The average RDW (SD and CV) of cases were higher than controls (P value = 0.000, 0.000 respectively). There was a significant difference in RDW-CV between mild and severe hypothyroidism (P value = 0.040). RDW-SD and RDW-CV had significant positive correlation within TSH (r = 0.361, P value = 0.000; r = 0.407, P value = 0.000 respectively) and significant negative correlation within T3 (r = - 0.419, P value = 0.000; r = - 0.507, P value = 0.000 respectively) and T4 (r = - 0.406, P value = 0.000; r = - 0.506, P value = 0.000 respectively). Conclusion: The study concluded that RDW was significantly higher in patients with hypothyroidism and had a significant positive correlation with TSH and a significant negative correlation within T3 and T4. So, RDW may be used as a significant clinical marker of hypothyroidism.

The relationship between thyroid disorders and vitamin A.: A narrative minireview

The terms "vitamin A" and "retinoids" encompass a group of fat-soluble compounds essential for human nutrition. Some of them (retinol, retinal, 9-cis-retinoic acid, tretinoin, and 13-cis-retinoic acid) are fully natural, while others are synthetic compounds used mostly for therapeutic purposes. Some evidence indicates that the nutritional status of these retinoids (i.e., the presence or absence of deficiency) is able to modulate thyroid gland metabolism. Vitamin A deficiency is tightly correlated with structural and functional impairment of the thyroid gland and is often associated with iodine deficiency. Furthermore, retinoids are involved in different immune functions, as well as in the process of activation, proliferation, and differentiation of regulatory T cells (Treg). This is particularly significant given the high prevalence of thyroid autoimmune disorders, whose pathogenesis seems to be related to the altered homeostasis of regulatory T cells. Retinoids are also involved in the modulation of gene expression via their interaction with nuclear receptors, and they also act as cofactors in cell growth and differentiation. The ability of retinoic acid to increase iodine uptake and sodium-iodine symporter activity in human thyroid cancer cell lines suggests that some retinoids and their derivatives may be of use in the treatment of different thyroid tumors. This minireview summarizes the current knowledge on the link between nutritional intake of vitamin A and various thyroid disorders.

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

Recognizing the importance of iodine deficiency as a single most important preventable cause of brain damage, World Health Organization (WHO) urged all countries to scale up salt iodization since 1991 where iodine deficiency was declared as a global public health problem. All countries committed to report on the national iodine status of school-aged children (6-12 years), every 3 years. This paper aims to evaluate the progress of countries in Eastern Mediterranean Region (EMR) toward the eradication of iodine deficiency disorders (IDD) and recommend operational action to support implementation of the WHO Regional Nutrition Strategy (2020-2030). Salt iodization in EMR has been scaled up with significant progress in increasing the proportion of dietary salt which is adequately iodized. As a result, many countries such as Qatar, Kuwait, Bahrain, Jordan, Oman, and Iran have achieved, or are now on the threshold of achieving IDD elimination. The WHO in coordination with United Nations Children's Fund is working with member states to ensure suitability of these achievements. Hence, efficient monitoring will help member states to measure the magnitude of IDD as a public health problem and to monitor the effects of the intervention on the iodine status of a population. Policy makers should take proactive steps to enforce mandatory regulatory measures for USI, through a multi-sectoral coordination, and careful assessments and estimates of iodine nutritional status. Coordination between the two national programs of USI and salt reduction intake is necessary.

Prevalence of Goiter and Associated Factors Among Adolescents in Gazgibla District, Northeast Ethiopia

Background

Although goiter is a major public health problem in Ethiopia and affects a large number of people, there was little evidence among adolescents particularly in Northern Ethiopia. This study was, therefore, aimed at investigating the prevalence of goiter and associated factors among adolescents in Gazgibla District, Northeast Ethiopia.

Methods

A community-based cross-sectional study was conducted among 596 adolescents from August 5–30, 2019. Data were collected using a structured questionnaire. Adolescents were assessed for goiter based on World Health Organization criteria. The level of iodine in household salt samples was tested using rapid test kit. Data were entered into EpiData version 3.1 and exported into Statistical Package for the Social Sciences version 22.0 for statistical analysis. Multivariable logistic regression analysis was done to control for all possible confounders and to identify predictors of goiter. Odds ratio along with 95% confidence interval (CI) was estimated to measure the strength of the association. Level of statistical significance was declared at P ≤ .05.

Results

The prevalence of goiter among adolescents was 42.5% (95% CI: 38.4%, 46.7%). Being a female (adjusted odds ratio [AOR] = 1.83, 95% CI: 1.18, 2.85), family history of goiter (AOR = 3.63, 95% CI: 2.31, 5.69), cabbage consumption at least once per week (AOR = 4.6, 95% CI: 2.42, 8.74), not consuming meat at all (AOR = 2.5, 95% CI: 1.17, 5.32), not consuming milk at all (AOR = 2.19, 95% CI: 1.19, 4.03), and inadequate iodine level of household salt (AOR = 7.05, 95% CI: 3.83, 12.97) were significantly associated with the development of goiter among adolescents.

Conclusions

The prevalence of goiter was very high in the study area. Therefore, the health sector of the district should invest efforts on improving the community’s awareness through disseminating key messages about iodized salt and iodine-rich foods.

Micronutrients, iodine status and concentrations of thyroid hormones: a systematic review

Context

The metabolism of thyroid hormones, which are essential for normal development, involves many proteins and enzymes. It requires iodine as a key component but is also influenced by several other micronutrients, including selenium, zinc, iron, and vitamin A.

Objective

This systematic review was designed to investigate the effect of micronutrient status and supplementation on iodine status and thyroid hormone concentrations.

Data Sources

Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, electronic databases were searched from their inception to April 2016.

Study Selection

Human studies published in English and reporting data on micronutrient status and iodine status and/or thyroid hormone concentrations were included. Studies that examined the effect of micronutrient supplementation on iodine status and/or thyroid hormone concentrations were also included.

Data Extraction

A predesigned and piloted data extraction form was used to compile data from individual studies.

Results

A total of 57 studies were included: 20 intervention studies and 37 observational studies. Although observational evidence suggests that concentrations of selenium, zinc, and iron are positively associated with iodine status, data from randomized controlled trials fail to confirm this relationship.

Conclusions

Further studies are needed to provide greater understanding of the role of micronutrient status in iodine nutrition and thyroid function to ascertain the public health implications for populations worldwide.

Goiter and its associated factors among primary school children aged 6-12 years in Anchar district, Eastern Ethiopia

BACKGROUND

Goiter is a major public health problem in Ethiopia. Even though there were studies done on goiter in Ethiopia, there was little evidence in the eastern part of the country. Therefore, the aim of this study was to assess the prevalence of goiter and its associated factors among school-age children in Anchar district of Eastern Ethiopia.

METHODS

A school based cross-sectional study was conducted from February 13 to 30, 2017. Multistage sampling method was used to select 418 children aged 6-12 years. Data were collected using a questionnaire. Children were examined for the presence or absence of goiter based on the criteria of the World Health Organization (WHO). Salt samples were tested using a rapid test kit. Data were entered to EpiData version 3.1 and exported to SPSS version 22.0 for analysis. Bivariate and multivariate logistic regression models were fitted; Crude Odds Ratio (COR) and Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) were computed. Level of significance was determined at p-value less than 0.05.

RESULTS

The total goiter prevalence rate was 51.8% (CI: 46.9%, 56.8%). Father's education (AOR = 1.87, CI: 1.06, 3.30), type of salt used (AOR = 2.09, CI: 1.13, 3.88), iodine level of salt (AOR = 2.77, CI: 1.11, 6.89), frequency of milk consumption (AOR = 3.65, CI: 1.63, 8.20), frequency of cabbage consumption (AOR = 7.74, CI: 4.48, 13.39), eating status of eggs (AOR = 3.16, CI: 1.54, 6.50), and eating status of dark green vegetables/fruits (AOR = 2.14, CI: 1.17, 3.93) were factors associated with goiter among school-age children.

CONCLUSIONS

The total goiter prevalence rate was very high. Therefore, the health and education sectors of the study area should work hand in hand to improve the awareness of the community about goiter, iodized salt and iodine rich foods.

Assessment of iodine supplementation program on thyroid function in Sudan

The aim of this Study is to investigate whether the Iodine Supplementation Programme is successful or not. This Programme was implemented in Nyala to treat the Iodine deficiency. In this Study Nyala was selected to act as (a study area), due to the history of Iodine deficiency of this region, while Khartoum was selected to act as (a control area). 2000 samples were collected from Khartoum versus 450 samples from Nyala. Thyroxine (T₄) and triiodothyronine (T₃) levels in two regions were measured and performed by using radioimmunoassay (RIA), also the immunoradiometric assay (IRMA) used for measurement of thyroid stimulating hormone (TSH). The obtained results analyzed by using Statistical Package for Social Sciences (SPSS). (Coherent retrospective) used to determine differences between the study groups. The results of this study showed, there was no significant difference between the mean serum concentrations of T3 and TSH for Khartoum and Nyala. T4of Khartoum (117.93 ± 42.797) nmol/L and the mean serum T4 of Nyala (114.54 ± 45.526) nmol/L, the (P-value = 0.133).T3for Khartoum (1.8040 ± 0.99047) nmol/L and T3of Nyala (1.7307 ± 0.96508) nmol/L, the (P-value = 0.153). TSH for Khartoum (1.4480 ± 0.95807)mIU/Land the mean serum TSH of Nyala (1.4553 ± 1.0244) mIU/L, the (P-value = 0.885). The study showed a clear observation of improvement of hypothyroidism cases in Nyala while the ratio decreased from 64.09% to 0.6%. All the results were carried out according to normal range of Sudanese. The conclusion from this study the iodine supplementation programme is successful. The study recommends rising the health awareness among people by explain the severity of iodine deficiency, and continue in iodine supplementation programme, also establishment of monitoring system including monitoring the presence of iodized diets (sugar, salt, oils, and bread) in the markets. Finally, further studies are needed in other parts of Sudan to assess the size of iodine deficiency problem.

Genetic and non-iodine-related factors in the aetiology of nodular goitre

Genetic and a large number of environmental non-iodine-related factors play a role in the cause of nodular goitre. Most evidence for the influence of genetic and environmental factors in the cause of goitre is from cross-sectional, population-based studies. Only a few studies have included prospective data on risk factors for nodular goitre, although few prospective data are available on the effect of iodine and tobacco smoking on goitre development. Goitre is not one single phenotype. Many epidemiological studies do not distinguish diffuse from nodular goitre, as the investigated parameter is often thyroid volume or frequency with increased thyroid volume. Moreover, information on the presence and effect of gene-environment, gene-gene, and environment-environment effect modifications is limited. Thus, firm conclusions about the relative contributions and causality of the investigated risk factors should be made with caution. Smoking seems to be an established risk factor for nodular goitre, possibly with effect modification from iodine intake, as the risk associated with smoking is smaller or absent in areas with sufficient iodine intake. The use of oral contraceptives might have protective effects against goitre, and childbirth is an increased risk factor for goitre in areas with non-optimal iodine intake. Insulin resistance is a recently investigated risk factor, and the risk of goitre may be reversible with metformin treatment. Iodine remains the major environmental risk factor for nodular goitre.

Determinants of cognitive performance in children relying on cyanogenic cassava as staple food

While risk factors for konzo are known, determinants of cognitive impairment in konzo-affected children remain unknown. We anchored cognitive performance (KABC-II scores) to serum levels of free-thyroxine (free-T4), thyroid-stimulating hormone (TSH), albumin, and motor proficiency (BOT-2 scores) in 40 children including 21 with konzo (median age: 9 years) and 19 without konzo (median age: 8 years). A multiple regression model was used to determine variables associated with changes in KABC-II scores. Age (β: -0.818, 95% CI: -1.48, -0.152) (p = 0.018), gender (β: -5.72; 95% CI: -9.87, -1.57 for females) (p = 0.009), BOT-2 score (β: 0.390; 95% CI: 0.113, 0.667) (p = 0.008), and free-T4 (β: 1.88; 95% CI: 0.009, 3.74) (p = 0.049) explained 61.1 % of variation in KABC-II scores. Subclinical hypothyroidism was not associated with poor cognition. A crude association was found between serum albumin and KABC-II scores (β: 1.26; 95 % CI: 0.136, 2.39) (p = 0.029). On spot urinary thiocyanate reached 688 μmol/l in children without konzo and 1,032 μmol/L in those with konzo. Female gender and low serum albumin are risk factors common to cognitive and proportionally associated motor deficits in children exposed to cassava cyanogens. The two types of deficits may share common mechanisms.

Prevalence and associated factors of goiter among rural children aged 6-12 years old in Northwest Ethiopia, cross-sectional study

Background

Goiter, an indicator of chronic iodine deficiency, is a major public health problem for populations living with iodine deficient environment, particularly for young children. It is a threat to the social and economic development of many developing countries including Ethiopia. The aim of the study was to assess the prevalence and associated factors of goiter among rural children aged 6-12 years, Northwest Ethiopia.

Methods

A community based cross-sectional study was employed from July to December 2012 in Lay Armachiho district. A total of 698 children aged 6-12 years were included in the study. Multistage sampling was used. Children were examined for the presence/absence of goiter using a criterion set by World Health Organization. The level of Iodine of the salt was estimated by using spot testing kits. Descriptive and summary statistics were employed. Bivariate and multivariate logistic regressions were used to identify associated factors. The degree of association was assessed by using Odds ratio with 95% confidence interval were computed to see the presence and strength of association.

Results

Totally 694 children were included in the analysis. The prevalence of goiter was found to be 37.6%. Goiter of grade 1 was 28.5% and that of grade 2 was 9.1%. 29.7% of the samples had adequate iodine content. The age of child (AOR: 1.24,95% CI: 1.12, 1.36), being female (AOR = 1.98, 95% CI: 1.38-2.85), salt iodine level (AOR = 0.44, 95% CI: 0.27, 0.71), family history of goiter (AOR = 3.18, 95% CI: 2.08, 4.858), fish consumption (AOR = 0.42, 95% CI; 0.22, 0.80) were factors associated with goiter.

Conclusion

Chronic iodine deficiency was a severe public health problem in the study communities. Ensuring the consumption of iodized salt and promotion of fish intake at the household level are highly recommended.

Excessive iodine intake, water chemicals and endemic goitre in a Sudanese coastal area

Objective

To study the associations between intakes of iodine and water chemicals and the thyroid gland status of schoolchildren living in the coastal city of Port Sudan.

Design

In our previous nationwide study on goitre, it was observed that the prevalence of goitre was high in Port Sudan city despite high urinary iodine excretion. A cross-sectional study including schoolchildren aged 6–12 years was designed. Measurements determined the prevalence of goitre, urinary iodine concentration and thiocyanate secretion in casual urine samples, serum levels of thyroxine, triiodothyronine, thyroid-stimulating hormone and thyroglobulin, as well as the levels of Cl–, F–, Ca2+, Mg2+and total hardness of drinking water.

Subjects

Schoolchildren (n654) aged 6–12 years.

Setting

Port Sudan city is located at the western bank of the Red Sea. The city is surrounded by a mountainous area known as the Red Sea Hills. It is the main sea port in the Sudan, inhabited by ethnically and socio-economically heterogeneous populations.

Results

The prevalence of goitre in Port Sudan was 34·86 % while the median urinary iodine concentration was 46·4 μg/dl. Out of thirty-one pupils from Port Sudan, twenty-four (77·42 %) were found to have urinary iodine concentration greater than 30 μg/dl and twelve (38·71 %) had different degrees of biochemical hypothyroidism. Excessive concentrations of Cl–, Ca2+, Mg2+and water hardness (369·2, 116·48, 60·21 and 539·0 mg/l, respectively) were detected in drinking water samples collected from Port Sudan that exceeded levels permitted by the WHO.

Conclusions

The coastal city of Port Sudan is a goitre-endemic area. In contrast to other Sudanese cities in which endemic goitre is related to iodine deficiency, goitre in Port Sudan is associated with iodine excess. Water chemicals seemed to have no effects on thyroid status.

Endemic goitre in the Sudan despite long-standing programmes for the control of iodine deficiency disorders

OBJECTIVE

To describe the status of iodine deficiency disorders (IDDs) in the Sudan more than 25 years after the initiation of IDD control programmes and to explore the causes of endemic goitre in the country.

METHODS

Testing for IDDs was carried out in 6083 schoolchildren 6 to 12 years of age from the capital cities of nine states in different areas of the country using the three indicators recommended by the World Health Organization: the prevalence of goitre, laboratory measurements of urinary iodine concentration in casual urine samples and serum thyroglobulin (Tg) levels. Serum levels of thyroxine (T4), triiodothyronine (T3) and thyroid-stimulating hormone (TSH), as well as urinary secretion of thiocyanate, which can affect the transport of iodine into thyrocytes, were also measured.

FINDINGS

The prevalence of goitre in the different samples ranged from 12.2% to 77.7% and was 38.8% overall. The overall median urinary iodine concentration was 6.55 μg/dl, with the lowest median value having been found in Kosti city (2.7 μg/dl), situated in the centre of the country, and the highest (46.4 μg/dl) in Port Sudan, on the Red Sea coast. The highest mean serum Tg level (66.98 ng/ml) was found in Kosti city, which also had the highest prevalence of goitre.

CONCLUSION

IDDs still constitute a public health problem throughout urban areas in the Sudan and iodine deficiency appears to be the main etiological factor involved.

Iodine deficiency and its association with intelligence quotient in schoolchildren from Colima, Mexico

Objective

To determine the prevalence of iodine deficiency, its causes and its association with intelligence quotient (IQ) in Mexican schoolchildren.

Design

Cross-sectional analytical study, in which determinations of thyroid gland size, urinary iodine excretion, IQ, iron nutritional status, physical anthropometry, family consumption of goitrogenic foods, type/origin and iodine saturation of salt consumed at home and coliform organisms in drinking water were performed, and the association of each variable with IQ scores was evaluated by multiple regression analyses.

Setting

Municipality of Cuauhtémoc, in Colima, Mexico (altitude: 600–2700 m above sea level). Sea salt is extracted manually nearby and often used for human consumption. Goitre remains present in the region despite over half a century of mandatory salt iodination in the country.

Subjects

Three hundred and three children, similar proportions of boys and girls, mean age 9·3 years, randomly selected from 19 public elementary schools.

Results

Overall goitre rate was 21·4 %; low urinary iodine excretion was found in 19·5 % of the children, high urinary iodine excretion in 32·0 %. IQ scores were transformed into percentile values, with the following categorisation: ≤P5 (low IQ), 48·5 %; >P5 to ≤P25 (below average), 24·2 %; >P25 to <P75 (average), 18·8 %; ≥P75 to <P95 (above average), 3·6 %; ≥P95 (high IQ), 4·9 %. Ninety-two per cent of the population used iodinated salt, but deficient iodine saturation (<50 ppm) was found in 86·8 % of salt samples. The main goitrogenic foods consumed were peanuts (by 31·5 % of the sample), cabbage (30·1 %), broccoli (27·7 %) and cauliflower (25·7 %). Median counts of coliform organisms (colony-forming units/100 ml of drinking water) were: 207·5 (well water), 151 (cisterns), 52 (private homes), 25 (elementary schools) and 12 (kindergartens). Moderate iodine deficiency was associated (P< 0·05) with a 4·26 times higher risk of low IQ.

Conclusions

There is a perturbing negative impact of these findings on human capital acquisition for the region and the country. More attention is needed to ensure effective salt iodination processes, particularly in regions where goitrogens may contribute to the negative effects of iodine deficiency on the intellectual development of children.

Goiter and other iodine deficiency disorders: A systematic review of epidemiological studies to deconstruct the complex web

A systematic review of the available literature on goiter and other iodine deficiency disorders (IDDs) was carried out with the aim of analyzing available evidence and providing inputs to the policy makers and program formulators regarding the entire issue. The findings point to major issues such as the following: methodological issues in epidemiology of goiter and other iodine deficiency disorders (IDDs); lacunae in causal linkages; inadequate attention to multicausality; flawed assessment of the impact of intervention, i.e., iodized salt; and harmful effects of iodine not given due cognizance. Most of the research to date has been unidirectional and does not provide comprehensive data on all aspects of IDDs. To further compound the issue, many independent researchers, on finding something different from the existing dominant paradigm (iodized salt as panacea for goiter) have tended to ignore these in their final conclusions and recommendations. Thus, evidence from this systematic review demonstrates enough basis to start a debate on the entire issue, recognizing opposing research findings while continuing with the present strategy. This imposes specific problems and necessitates area-specific solutions instead of a universal solution, which apart from being less effective may be harmful in the long run.

Isoflavone supplements do not affect thyroid function in iodine-replete postmenopausal women

Despite the safety review conducted by the U.S. Food and Drug Administration in the process of awarding a health claim for the cholesterol-lowering properties of soy protein, concerns about the possible goitrogenic effects of soybean isoflavones persist. Concerns are based primarily on in vitro research, animal studies, and older reports of goiter in infants fed soy formula not fortified with iodine. In a randomized, double blind, placebo-controlled study, we investigated the effect on thyroid function of a daily supplement containing 90 mg (aglycone weight) of total isoflavones/day versus placebo in 38 postmenopausal women, 64-83 years old, not on hormone replacement therapy. Serum thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) were measured at baseline and after 90 and 180 days. In the supplement group, at baseline and 6 months, TSH (micro U/ml), T4 (nM), and T3 (nM) levels (mean +/- SE) were 3.00 +/- 0.44, 149.00 +/- 5.04, and 1.53 +/- 0.13, respectively, and 3.49 +/- 0.52, 154.52 +/- 2.09, and 1.78 +/- 0.12, respectively. In the control group, levels at baseline and at 6 months were 3.35 +/- 0.51, 145.39 +/- 6.69, and 1.55 +/- 0.18, respectively, and 3.63 +/- 0.57, 153.77 +/- 6.64, and 1.75 +/- 0.10, respectively. Intragroup differences for all three measures were statistically indistinguishable at 6 months, and levels were similar between the isoflavone supplement and placebo groups at each measurement. These results indicate that in this group of healthy iodine-replete subjects, soy isoflavones do not adversely affect thyroid function.