Endemic goitre in the Darfur region (Sudan). Epidemiology and aetiology

Does fluoride exposure affect thyroid function? A systematic review and dose-response meta-analysis

INTRODUCTION

Fluoride exposure may have various adverse health effects, including affecting thyroid function and disease risk, but the pattern of such relation is still uncertain.

METHODS

We systematically searched human studies assessing the relation between fluoride exposure and thyroid function and disease. We compared the highest versus the lowest fluoride category across these studies, and we performed a one-stage dose-response meta-analysis for aggregated data to explore the shape of the association.

RESULTS

Most retrieved studies (27 of which with a cross-sectional design) were conducted in Asia and in children, assessing fluoride exposure through its concentrations in drinking water, urine, serum, or dietary intake. Twenty-four studies reported data on thyroid function by measuring thyroid-related hormones in blood (mainly thyroid-stimulating-hormone - TSH), 9 reported data on thyroid disease, and 4 on thyroid volume. By comparing the highest versus the lowest fluoride categories, overall mean TSH difference was 1.05 μIU/mL. Dose-response curve showed no change in TSH concentrations in the lowest water fluoride exposure range, while the hormone levels started to linearly increase around 2.5 mg/L, also dependending on the risk of bias of the included studies. The association between biomarkers of fluoride exposure and TSH was also positive, with little evidence of a threshold. Evidence for an association between fluoride exposure and blood concentrations of thyroid hormones was less evident, though there was an indication of inverse association with triiodothyronine. For thyroid disease, the few available studies suggested a positive association with goiter and with hypothyroidism in both children and adults.

CONCLUSIONS

Overall, exposure to high-fluoride drinking water appears to non-linearly affect thyroid function and increase TSH release in children, starting above a threshold of exposure, and to increase the risk of some thyroid diseases.

Potential and unrealized future possibilities of browntop millet in the food sector

Browntop millet (BTM) is small-seeded annual grass cultivated as grain crop, primarily on the marginal lands in dry areas in temperate, subtropical and tropical regions. It is increasingly receiving attention of the scientific community. Aim of this systematic review is to study the physiochemical, sensory, functional and nutritional properties as well as health benefits of browntop millet. This paper is based on quantitative and qualitative secondary data obtained from 71 out of 208 descriptive and scientific literature reviewed and analyzed from the national and international electronic platforms. The scientific literature based on browntop millet has been found scanty. According to the few studies available energy ranges from 338.0 kcal to 368.62 kcal. The carbohydrate, crude fiber and fat content of BTM is 71.32 gm, 8.06–16.08%, 1.89 gm, respectively. Protein is between 11.64% and 10.72%. Browntop millet contains phytochemicals such as flavonoids, quinones, tannins, and resin. There is galore scope for development and standardization of value added products made from browntop millets such as ready to eat foods (cookies, bars, deserts, etc) and ready to cook foods (idli mix, poha, etc) in which the millet can be used in combination with other cereal grains. Thus, browntop millet holds great potential in alleviating food and nutrition insecurity. It has good nutritional value. It can be used for the prevention and management of several non-communicable diseases. In order to make this smart food popular among farmers and consumers, systematized studies in the field of agriculture, nutrition, toxicology, naturopathy and biomedical sciences need to be done and documented properly. From ancient times BTM has been used in many forms such as forage, staple food or in many traditional dishes. An e-repository can be made of the traditional Indian foods made from BTM to popularize its use among the younger generations.

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.

Antinutritional factors in pearl millet grains: Phytate and goitrogens content variability and molecular characterization of genes involved in their pathways

Pearl millet [Pennisetum glaucum (L.) R. Br.] is an important "orphan" cereal and the most widely grown of all the millet species worldwide. It is also the sixth most important cereal in the world after wheat, rice, maize, barley, and sorghum, being largely grown and used in West Africa as well as in India and Pakistan. The present study was carried out in the frame of a program designed to increase benefits and reduce potential health problems deriving from the consumption of pearl millet. The specific goal was to provide a database of information on the variability existing in pearl millet germplasm as to the amounts of phytate, the most relevant antinutrient compound, and the goitrogenic compounds C-glycosylflavones (C-GFs) accumulated in the grain.Results we obtained clearly show that, as indicated by the range in values, a substantial variability subsists across the investigated pearl millet inbred lines as regards the grain level of phytic acid phosphate, while the amount of C-GFs shows a very high variation. Suitable potential parents to be used in breeding programs can be therefore chosen from the surveyed material in order to create new germplasm with increased nutritional quality and food safety. Moreover, we report novel molecular data showing which genes are more relevant for phytic acid biosynthesis in the seeds as well as a preliminary analysis of a pearl millet orthologous gene for C-GFs biosynthesis. These results open the way to dissect the genetic determinants controlling key seed nutritional phenotypes and to the characterization of their impact on grain nutritional value in pearl millet.

Iodine deficiency status in the WHO Eastern Mediterranean Region: a systematic review

Iodine deficiency is a global public health issue because iodine plays a major role in the thyroid hormone synthesis and is essential for normal neurological development. This review summarizes the publications on iodine status in the WHO Eastern Mediterranean Region (EMR) countries. All related studies available in main national and international databases were systematically searched using some specific keywords to find article published between 1909 and 2015. The prevention of iodine deficiency disorders (IDDs) in the WHO EMR countries is currently under control without significant side effects. Mild to severe IDDs exist in some countries of the Middle East, due to lack of effective iodine supplementation program, but the Islamic Republic of Iran, Jordan, Bahrain and Tunisia have achieved the goal of universal salt iodization. Overall, despite enormous efforts to control IDDs, still IDD remains a serious public health problem in some countries of the region, requiring urgent control and prevention measures.

Factors affecting sustainable iodine deficiency elimination in Pakistan: A global perspective

Iodine deficiency remains a considerable challenge worldwide, even after decades of efforts to address the problem. The aim of this review is to present the current situation in historically iodine-deficient Pakistan regarding iodine nutritional status and place it in a global perspective. We collected relevant articles from online bibliographic databases and websites of concerned organizations that addressed prevalence of goiter/iodine deficiency and barriers to sustainable control. We divided the studies into pre- and post-1994, a landmark year when Pakistan formally adopted the universal salt iodization (USI) programme. Overall, 56 studies reported goiter/iodine deficiency prevalence in Pakistan. Before 1994, six studies (30%) reported a goiter prevalence ≥70%, while nine studies (45%) reported a goiter prevalence between 30% and 70%. Only five studies (25%) found a goiter prevalence less than 30%, of which only two studies reported prevalence <10%. From 1994 onwards, 15 studies (41.7%) reported a goiter/iodine deficiency (ID) prevalence ≥50%, of which seven studies reported prevalence ≥70%, while three studies (8.3%) found a goiter prevalence of 30%-49%, nine studies (25%) found a goiter prevalence of 10%-29%, and five studies (13.9%) reported prevalence of <10%. Four studies (11.1%) reported lower goiter prevalence but higher prevalence of iodine deficiency. The efforts in the past two decades resulted in up to a 50% decline in iodine deficiency disorders (IDD). Variable remaining factors and the recent results, however, indicate that this decline may be non-uniform and even over-estimated. Coordinated and regionally adopted efforts for eradication of IDD from all stakeholders should be pursued. Policy makers should take steps to protect future generations and alert concerned organizations about the importance of careful assessments and estimates of iodine nutritional status.

Iodine deficiency among goiter patients in rural South Sudan

Background

It is estimated that 2.2 billion or approximately 30% of the world’s population live in iodine-deficient areas. In a 2005 study households consuming iodized salt in South Sudan increased from 40% to 73%. Despite this achievement, there are still many goiter cases in rural South Sudan and iodine deficiency remains as a major public health problem in this part of sub Saharan Africa.

The purpose of this study therefore was to determine the prevalence of iodine deficiency among rural Southern Sudan goiter patients.

Methods

A cross-sectional study was carried out in three South Sudan counties, adults with goiter were from three centers following a mobilization campaign that lasted 4 weeks for free medical care. They were clinically evaluated and completed interviewer administered questionnaires to determine their age, gender, diet, family history, drug history, and medical history. Urine samples were then taken for urinary iodine levels. The outcome was iodine deficiency measured as urinary iodine less than 100 μg per/ L. Multiple logistic regression was used to establish the factors associated with iodine deficiency in South Sudan. Ethical approval was obtained.

Results

A total of 286 goitre patients were recruited. The mean age was 38 years (SD 9), 262(92%) were females (F: M ratio 11:1), and 257(90%) were rural- peasants, 25% (20/286) had moderate to severe iodine deficiency. 174(62%) consumed non-iodized salts.

Conclusion

Iodine deficiency is highly prevalent among rural South Sudan communities and a likely cause for goiters. Rural poor women are highly vulnerable.

Cancer in the Sudan: an overview of the current status of knowledge on tumor patterns and risk factors

The Sudan, the largest and most diverse country in Africa, is experiencing a growing cancer problem, but little is presently known on tumor patterns, cancer epidemiology and ethnic or environmental cancer risk factors. We review here the current status of knowledge, summarizing data from local and international publications as well as primary information from the only two cancer hospitals of the country, both located in Central Sudan (Khartoum and Wad Medani). We provide frequencies reported for cancers detected in adults and children, and summarize studies on specific cancer types, as well as information on risk factors that most likely impact on tumor patterns.

The use of sugar as a vehicle for iodine fortification in endemic iodine deficiency

The use of sugar as a vehicle for iodine supplementation was explored in a study of iodine deficiency in the Sudan. A survey of sugar consumption was conducted and established a widespread and uniform intake of sugar in all ages with no differences among socio-economic groups. The daily intake among adults varied from 48 g to 78 g as examined in five different geographical areas in the country. Iodinated sugar was produced by addition to sugar solution prior to crystallisation in an evapocrystallizer or sprayed on the conveyor of cured sugar before it entered the dryers. Subsequently, the iodinated sugar was given to members of 18 and 60 families in a mildly (urinary iodine < 5.1 micrograms/dl) and moderately (urinary iodine < 3 micrograms/dl) iodine deficient areas, respectively, over a 1-month and a 6-month period, respectively. In both tests, improvements were recorded, i.e. the rates of goitre decreased, urinary iodine levels increased significantly (from 5.1 to 14.4 micrograms/dl and from 3 to 9.8 micrograms/dl, respectively) and thyroid hormones values rose. No side effects were noted. The results indicate that fortification of sugar with iodine may serve as a new alternative approach in attempts to eradicate iodine deficiency related disorders in endemic areas.

Goitrous endemic in Guinea

We identified a major goitrous area in the Republic of Guinea, characterised by an overall goitre prevalence of 70% in adults. Thyroid swelling was sometimes present at birth and affected 55% of schoolchildren. A difference between sexes appeared at puberty. Endemic cretinism, mainly in its myxoedematous form, was found in about 2% of goitrous patients. In this region, iodine deficiency is the primary causative factor (median urinary concentrations of 16 micrograms/L, and in 69% of inhabitants below the critical threshold of 20 micrograms/L). The diet contained substantial amounts of thiocyanate anions (median 6 mg/L in urine and in 27%, more than 10 mg/L) likely to further depress iodine bioavailability. Other dietary compounds, notably flavonoids were suspected to contribute. Overall nutritional and general health appeared satisfactory. The affected population is borderline euthyroid with a trend towards hypothyroidism in protracted disease. This area of Guinea may be regarded as the epicentre of the west African endemic and as one of the most severely goitrous regions ever described, requiring urgent public health measures.

Endemic juvenile hypothyroidism in a severe endemic goitre area of Sudan

OBJECTIVE

The aim of the study was to assess thyroid function, iodine intake and exposure to dietary goitrogens of children living in an area with a high prevalence of goitre, in the region of Darfur, Sudan.

DESIGN

In a village where goitre affected approximately 85% of children, a cross-sectional survey of thyroid function was performed in children 0-7 years old.

PATIENTS

Twenty neonates and 190 children, aged 1 month to 7 years, were included.

MEASUREMENTS

Thyroid hormones, urinary iodide and thiocyanate excretion were measured.

RESULTS

Mean +/- SD serum T4 was below the normal range at birth (82 +/- 50 nmol/l) and in the age group less than 2 years (73 +/- 46). Children older than 2 years had even lower serum T4: 37 +/- 37 (P < 0.001) at 3-4 years and 36 +/- 38 (P < 0.001) at 5-7 years. Mean serum TSH was 25.8(6.2-107.7) mU/l at birth, 8.3(2.5-27.8) in the group less than 2 years, 15.3(2.9-79.1) at 3-4 years and 16.4(2.7-98.3) at 5-7 years. The overall prevalence of hypothyroidism (TSH > 50 mU/l) was 24%. Mean urinary thiocyanate was high at birth (107 +/- 69 mumol/l), normal in the group less than 2 years and higher in children older than 2 years (126 +/- 69 mumol/l) (P < 0.001). All age groups had a low urinary iodide concentration.

CONCLUSION

Hypothyroidism was very frequent in each age group. The higher frequency of hypothyroidism observed in weaned children (> 2 years) was attributed to the combined effects of iodine deficiency and goitrogens (thiocyanate and glycosylflavones) derived from millet.

Goitre in Ethiopia

A stratified goitre survey was conducted on 35,635 schoolchildren and 19,158 household members in all Regions of Ethiopia except Eritrea and Tigrai. The gross goitre prevalence (mean of male and female values) among schoolchildren and household members was 30.6 and 18.7% respectively, while that of visible goitre was 1.6 and 3.2% respectively. Prevalence was higher in females (27.3% in household members and 36.1% in schoolchildren) than in males (10.1% in household members and 25.1% in schoolchildren) and increased with age more in females than in males. The prevalence rates at higher altitudes were higher than those at lower altitudes in both schoolchildren and household members. Using an epidemiological model the consequences of iodine deficiency, including cretinism and maternal wastage, have been estimated.

Epidemiology of iodine deficiency

Iodine deficiency (ID) causes goiter, cretinism, neonatal hypothyroidism, irreversible mental retardation, and child and infant death. Over one billion people are at risk, most of them in developing countries. While ID is the primordial factor in these conditions, other environmental and host factors significantly modify the magnitude and clinical presentation of iodine deficiency disorders. The interactions and mechanisms by which these factors operate are complex and mostly unknown, requiring more investigation.

Endemic goitre--iodine deficiency disorders

Endemic goitre occurs when the prevalence of thyroid enlargement in the population of an area exceeds 10%. With few exceptions its cause is iodine deficiency superimposed on other goitrogenic factors normally present and responsible for sporadic goitre. Iodine deficiency causes significant health problems and so, the term iodine deficiency disorders (IDD) has been introduced. The earliest sign of IDD is goitre, but these disorders also include cretinism, neonatal hypothyroidism and congenital defects, as well as retardation of mental and physical development etc. IDD are a worldwide problem: WHO estimates that substantially more than 800 million people are at risk and more than 190 millions suffer from IDD; over 3 million people have cretinism and in the largest and worst affected areas many millions suffer from mental and physical developmental defects. IDD can be totally eliminated by prophylaxis using iodine administered in salt, oil or some other vehicle. Problems over preventing iodine deficiency relate to difficulties in the handling and distribution of the iodized vehicle in some parts of the world and on the political will to introduce preventive schemes. In only a very few areas does the presence of goitrogenic agents in the environment cause endemic goitre despite adequate iodine supply. In a limited number of places excessive iodine from seaweed used as staple food results in endemic goitre.

Endemic goiter and endemic thyroid disorders

The primary role of iodine deficiency in goitrogenesis and the prevention and treatment of endemic goiter by iodine supplementation is firmly established. Unfortunately, implementation of iodine prophylaxis programs has met with considerable technical and socioeconomic difficulties. Besides, lack of knowledge concerning some of the other causative factors of endemic goiter has prevented development of appropriate measures for its complete eradication in those areas where goiter persists in spite of prolonged and adequate iodine supplementation. At present, no less than 5% of the world's population have goiters and associated disorders, resulting in a public health and socioeconomic problem of major proportions. Seventy-five percent of people with goiter live in less developed countries where iodine deficiency is prevalent. Goiter prevalence rates of more than 50% and the highest frequency of severe cases of iodine deficiency disorders, namely, cretinism, congenital hypothyroidism, and various degrees of impairment of growth and mental development are found in endemic areas with extreme iodine deficiency. Goiters are usually multinodular and of very large size, producing, on occasion, signs of compression that require surgery. Recurrence rates are as high as 25-30% and second surgery accounts for 16% of all thyroidectomies. Unfortunately, most of these goiters occur in areas with highly restricted medical and surgical facilities. Twenty-five percent of people with goiters live in more developed countries where goiter continues to occur in certain areas despite iodine prophylaxis. Iodine-sufficient goiters are associated with autoimmune thyroiditis, hypothyroidism, hyperthyroidism, and thyroid carcinoma. Goiter is of considerable surgical significance in iodine-sufficient endemic areas and, to a lesser degree, in nonendemic areas where it is called "sporadic" goiter. Recurrence rates of iodine-sufficient goiter are 10-19% following thyroidectomy. Since most of these goiters grow by mechanisms other than increased thyrotropin (TSH) stimulation, treatment with suppressive doses of L-thyroxine is inefficient and, because of possible complications, not recommended. Although Graves' hyperthyroidism is not directly related to endemic goiter, it does relate adversely with ingestion or administration of iodine. At present, Graves' disease is treated with 131I or antithyroid drugs in more than 90% of the cases. The incidence rates of papillary, follicular, and anaplastic thyroid carcinomas appear to be related to endemic goiter and iodine supplementation, with surgery being required in essentially all of these cases.

Goitrogens

A large number of agents in the environment and some medications are known to interfere with thyroid gland function, posing the danger of thyroid disease. Pollutants that cause goitre are known as environmental goitrogens which may cause the condition by acting directly on the thyroid gland but also indirectly by altering its regulatory mechanisms and the peripheral metabolism and excretion of thyroid hormones. However, the mechanism that induces the trophic changes leading to goitre formation, and in some instances with hypothyroidism, is not well understood. Antithyroid compounds may enter into the water, air and food exposure pathways, becoming an important environmental goitrogenic factor in man and other animals. Naturally-occurring and anthropogenic agents may act as goitrogens, as well as some drugs, which in the presence of dietary iodine deficiency may exaggerate the goitre and associated disorders. In iodine-sufficient areas, these compounds may be responsible for the development of some "sporadic' goitres or the persistence of the goitre endemia with its associated disorders. At present, medical or surgical treatments for the individual, but not measures for prevention and control at community level, are being applied in iodine-sufficient goitre areas.

Prophylaxis and treatment of endemic goitre in Western Sudan with intramuscular iodized oil

A single injection of iodized oil was administered intramuscularly in a dose of 0.2-2 ml (475 mg iodine per ml) to 383 children from the villages of Kas and Dibbis of the Darfur region in Western Sudan, where goitre is prevalent. After one year the prevalence of goitre had declined from 76% to 49.6%. Of the goitrous children, 81.1% showed either complete resolution of goitre or definite regression of its size. None of the nongoitrous children developed goitre and none of the existing goitres became larger. No cases of hyper- or hypothyroidism were observed. The full 270 children were followed up for four-and-a-half years after treatment and compared with untreated controls from the same area. The prevalence of goitre was significantly lower in the treated than in the untreated group. In treated children the mean urinary iodine excretion three-and-a-half years after treatment was 188.7 micrograms/g creatinine. This was significantly higher than in the untreated group (P less than 0.001). One year later the mean urinary excretion of iodine in the treated children had decreased to 87.1 micrograms/g creatinine. There was no difference in the mean serum values of T3 and T4 in the treated and untreated groups. The level of thyroid stimulating hormone was significantly lower in the treated [mean (S.D.) = 3.5 (0.9)] than in the untreated children [6.0 (3.5)]. It is concluded that a single injection of iodized oil is safe and effective in prevention of goitre development, reduces goitre size and maintains a sufficient iodine supply to prevent goitre for at least four-and-a-half years in children from goitre-endemic areas in Western Sudan.