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

Prevalence and determinants of goitre among children of South Kordofan state, Sudan, 2021: an urgent need for effective implementation of universal salt iodisation

OBJECTIVE

This study aimed to determine the prevalence and determinants of goitre among children aged 6-12 years at South Kordofan state.

DESIGN

This was a cross-sectional facility-based study.

SETTING

The study was conducted in twenty villages of South Kordofan state during a medical mission.

PARTICIPANTS

All 575 school-age children (6-12 years) who attended the medical day were examined for clinical assessment of goitre.

RESULTS

The prevalence of goitre among children of South Kordofan was 42·8 % (grade 1: 15·7 %, grade 2: 27·1 %). Only 24·2 % of caregivers reported using iodised salt. Mothers working as farmers (OR: 3·209, CI 95 % 1·437, 7·167; P = 0·004) and children of Darforian tribes (OR: 21·799, CI 95 % 2·566, 185·226; P = 0·005) were found to be significantly associated with higher prevalence of goitre among children. This contrasts with children of African tribes, where they were found to have less goitre prevalence (OR: 0·432, CI 95 % 0·213, 0·875; P = 0·02). Iodised salt utilisation (OR = 0·523, CI 95 % 0·320, 0·854; P = 0·01) was found associated with a lower prevalence of goitre.

CONCLUSION

Even though National Iodine Deficiency Disorders control programs were initiated in Sudan more than 25 years ago, the prevalence of goitre among children in South Kordofan state was alarming (42·8 %). Efforts to improve access to iodised salt, increase utilisation and raise awareness are urgently needed.

Clinicopathological profile and management of thyroid carcinoma: a Sub-Saharan country experience

BACKGROUND

In Sudan, there is limited knowledge on the epidemiology, clinical characteristics and pathological patterns of thyroid cancer. To address this shortcoming, we studied the clinical, pathological and treatment patterns of thyroid cancer at the National Cancer Institute ‒ University of Gezira (NCI-UG), Sudan.

METHODS

We performed a retrospective health facility-based study of patients with thyroid cancer who were treated at NCI-UG from January 2009 to December 2017.

RESULTS

A total of 139 patients with thyroid cancer were identified during the study period. Tumors were more common among women (69%). Goiter was the main presenting symptom (85%). The most common type of thyroid cancer was follicular carcinoma (41%), followed by papillary carcinoma (24%), then anaplastic carcinoma (20%). The mean age of the women was 56.3 years (SD ± 14.7), compared to 52.5 years (SD ± 16.6) for the men. The frequencies of stage I, II, III, and IV were 17%, 22%, 16%, and 45%, respectively. Different types of thyroidectomies were performed in 79% of the cases, lobectomy in 4%, and no surgery in 17%. Only 28% of the cases received radioactive iodine. Palliative chemotherapy and radiotherapy were prescribed to 17% and 37% of the cases, respectively.

CONCLUSION

Thyroid cancer is more prevalent among women and most patients present at later stages. The dominance of follicular type suggests that the majority of this population is iodine-deficient.

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.

Knowledge, attitude, and practice of iodized salt use in Al-Riyadh and Al-Ozozab areas, Khartoum, Sudan

Iodine deficiency and subsequent iodine deficiency disorders have been a longstanding problem in many areas of the world, including Sudan, and still remains as the leading cause of preventable brain damage. According to the Sudan Household Health Survey, in 2006, the consumption of iodized salt in Sudan was 11%, only to deteriorate later on in 2011 to 9.5%. This is a descriptive cross sectional study which assesses the knowledge, attitude, and practice regarding the use of iodized salt in two socioeconomically different residential areas, Al-Riyadh and Al-Ozozab, Khartoum city, Sudan. From total of 152 participants selected from Al-Riyadh and Al-Ozozab areas (50% from each), there were 87 (57 %) females. Participants from Al-Riyadh had a higher educational and income level than those from Al-Ozozab, and better knowledge regarding the importance of regular iodized salt consumption to treat iodine deficiency (61% and 54%, respectively). However, only 39% of the participants were actually buying iodized salt. There was a significant relationship between residency and buying of iodized salt among the participants from Al-Riyadh (49%) and Al-Ozozab (30%) areas (p-value = 0.02). There was also significant association between the educational level and buying iodized salt (p-value = 0.014), but not with the income (p-value = 0.23). The consumption of potential goitrogenic foods (pearl millet or peanut butter) was high among the participants (n = 142) from Al-Riyadh and Al-Ozozab, and constituted 76% and 83%, respectively. Compulsory national salt specification needs to be established in Sudan, together with monitoring the market availability of iodized salt.

Reference intervals of thyroid hormones in Khartoum, Sudan

Objectives

This study aimed to establish the reference intervals (RIs) of thyroid function test among the adult Sudanese population in Khartoum, Sudan. A multi-stage survey stratified sampling method was used. Total triiodothyronine (TT3), total thyroxine (TT4) level and thyroid stimulating hormone (TSH) levels were measured using radioimmunoassay gamma counter (Riostad, Germany) to determine the reference intervals.

Result

A total of 390 adults aged 20–75 years (male: 40.5%, female: 59.5%) were recruited. The median (95% intervals) serum TSH, TT4 and TT3 levels were 1.2 (0.50–3.1) mIU/L, 103.0 (63.0–159.0) nmol/L and 1.4 (0.8–2.7) nmol/L respectively. Compared with males; females had significantly lower TSH level and significantly higher TT4 level, but there was no significant difference when the TT3 level was assessed. While there was no significant difference in the level of TSH and T3 in the age group, T4 levels have shown a progressive increase with age. In summary the RIs for TSH, TT4 and TT3 in this setting were different from the levels provided by the manufacturers. A significant different was observed in TSH and FT4 when considering gender issue. The RIs were not different in the different age groups except for FT4.

Reference intervals of thyroid hormones in a previously iodine-deficient area in Darfur, Sudan

BACKGROUND

Thyroid-stimulating hormone (TSH), thyroxin (T4) and T3 levels are varied in the different settings with disorders of thyroid homeostasis. It is recommended that every setting has to establish its own reference intervals (RIs) for these hormones.

METHODS

A multi-stage stratified sampling method was used to select a representative sample of a Sudanese adult (>20 years of age) in Nyala in western Sudan in the Darfur region during the period between January and June 2016 to establish RIs of thyroid-related hormones (TSH, T4 and T3).In this study, 1753 serum samples (male and female) with different age groups were investigated. A radioimmunoassay gamma counter was used to measure the level of these hormones.

RESULTS

The median (95% intervals) of serum TSH, T4 and T3 levels was 1.2 (0.50-3.0) mIU/l, 111.0 (72.0-161.0) nmol/l and 1.5 (0.8-2.8) nmol/l respectively.While the level of TSH was significantly higher in the age group between 31 and 40 years, both T4 and T3 levels have shown a progressive increase with age. There was no significant difference in the TSH, T4 and T3 level when the RIs were compared between males and females.

CONCLUSION

The RIs for TSH, T4 and T3 in this setting were different from the levels provided by the manufacturers. The RIs were different in the different age groups.

Nitric oxide is involved in the hypothyroidism with significant morphology changes in female Wistar rats induced by chronic exposure to high water iodine from potassium iodate

Epidemiological studies indicated that chronic exposure to high water iodine is associated with primary hypothyroidism (PH) and subclinical hypothyroidism (SCH). However, the mechanism is not well understood. In this study, we explored whether chronic exposure to high water iodine from potassium iodate (KIO₃) can induce hypothyroidism in addition to determining if nitric oxide (NO) is involved in the pathogenesis. 96 female Wistar rats were divided into six groups: control, I_1000μg/L, I_3000μg/L, I_6000μg/L, N-nitro-L-arginine methylester (L-NAME) and L-NAME+I_6000μg/L. After 3 months, urine iodine concentration, thyroid hormone, NO and nitric oxide synthase (NOS) serum levels were determined. Additionally, thyroid expression of inducible nitric oxide synthase (iNOS) was also investigated. Thyroid morphology was observed under light microscopy and transmission electron microscope. SCH as indicated by elevated serum thyrotropin (TSH) was induced among rats exposed to 3000 μg/L I^-, while rats treated with 6000 μg/L I^- presented PH characterized by elevated TSH and lowered total thyroxine in serum. Moreover, serum NO, NOS and iNOS expression in the thyroid were significantly increased in I_3000μg/L and I_6000μg/L groups. Changes in thyroid function and morphology in the L-NAME+I_6000μg/L group were extenuated compared to I_6000μg/L group. These findings suggested that chronic exposure to high water iodine from KIO₃ likely induces hypothyroidism with significant morphology changes in female Wistar rats and NO appears to be involved in the pathogenesis.

Prevalence of Goitre in Raichur District (Karnataka): A Descriptive Study

This prevalence study was exclusively for the goitre detection in individuals who has no prior awareness of thyroid disorder and also those patients giving history of signs and symptoms of such conditions. Subjects underwent investigations for (T3, T4, TSH and FNAC) to analyze status and type of Goitre. Of the first 30 cases, only 8 cases were investigated and later on personal  interest  for confirmation of goitre disorder prevalence additional 70 cases were assessed of which 51 cases were investigated. On basis of investigation and epidemiology, we concluded that probably soil and water sources contain less iodine. Sample shown are comparatively less, but in our area number of goitre  cases are more and it needs further extensive survey.

Urinary iodine concentration and thyroid hormones: Korea National Health and Nutrition Examination Survey 2013-2015

PURPOSE

An epidemiologic study that evaluated population's iodine nutrition status and its relationship with thyroid hormones is lacking in iodine-sufficient area. This nationwide study aimed to evaluate the iodine nutrition status in Korea and relationship between urine iodine concentration (UIC) and thyroid hormones.

METHODS

A total of 8318 subjects of the Korea National Health and Nutrition Examination Survey VI (2013-2015) with UIC and thyroid hormone evaluation were included. Median UIC level and estimated 24-h iodine intake were calculated. The prevalence of iodine deficiency or excess was obtained using estimated average requirement or above the tolerable upper intake level cut-point method by estimated iodine intake. We analyzed UIC with regard to age, sex, social economic status, and geographic characteristics.

RESULTS

The median UIC in general population and estimated iodine intake in adult population were 293.9 μg/L (above requirement according to World Health Organization classification) and 249.3μg/day, respectively. The prevalence of iodine deficiency and excess was 14.0 and 13.4%. The median UIC was higher among SAC [511 (299.9-948.5)] and lower among seventies [251.2 (98.9-761.6)] compared to other age groups. The median UIC increased with household income level (p for trend < 0.001). The subjects living in rural and inland region had lowest UIC among the enrolled subjects. The subgroups with higher median UIC were associated with higher mean TSH levels.

CONCLUSIONS

This first nationwide study in Korea demonstrated that the median of UIC and estimated iodine intake lie at nearly 300 µg/L and 250 µg/day, respectively, which shows an overall excellent iodine nutrition.

Environmental, urinary iodine status and prevalence of goitre among schoolchildren in a high altitude area of Saudi Arabia

Objective:

This study aimed to assess the iodine deficiency, prevalence of goitre among schoolchildren and measuring environmental iodine in Taif city, Saudi Arabia.

Methods:

A cross-sectional multistage cluster-sampling methodology was done on 1887 schoolchildren. Their urinary iodine concentration (UIC) and goitre prevalence was assessed. Blood level of triiodothyronin, thyroxine and thyroid-stimulating-hormone was carried out for students with normal, mild; moderate and sever iodine deficiency. The iodine content of salt, water and soil was also assessed.

Results:

Goitre prevalence was 7.4% and about 71% of the participants had UIC less than 100μg/L. An inverse relationship between median UIC and the percent prevalence of goitre was found. The mean serum T3, T4 and TSH were 1.05ng/dL, 6.81µg/dL, and 5.69mIU/L, respectively. A significant positive correlation was found between the mean value of urinary iodine and the mean value of both T3 and T4. While a significant negative correlation between the mean value of urinary iodine and the mean value of TSH was also noted.

Conclusions:

The results revealed the presence of a potential public health problem of iodine deficiency among school going children in high altitude areas of Saudi Arabia. There is a need to monitor and evaluate the salt iodization process, and distribute adequately iodized salt in the affected areas.

A cross-sectional comparison study on the iodine nutritional status between rural and urban residents in Zhejiang Province, China

OBJECTIVES

To evaluate the difference of iodine nutritional status between rural and urban residents under the universal salt iodisation policy.

SETTING

A multistage cluster sampling technique was employed in the present cross-sectional study. In total, 3300 rural and 3300 urban households were selected where the investigation was conducted.

PARTICIPANTS

A total of 8553 rural and 8909 urban residents participated in this provincial survey.

PRIMARY AND SECONDARY OUTCOME MEASURES

Spot urine samples were collected and the iodine concentration in urine was determined by the modified acid-digestion method.

RESULTS

The median urinary iodine concentration of rural residents was 170.1 μg/L, which was higher than that of urban residents with 153.5 μg/L. For school-aged children, middle-aged people and older people, the median urinary iodine concentration of rural residents was 191.2, 160.2 and 154.0 μg/L, respectively, which was higher than that of urban residents with 166.2, 153.8 and 129.5 μg/L, respectively. Risk factors for urinary concentration of rural residents were age (OR=0.99), terrain (OR=0.83), usual intake of pickled products (OR=1.45) and non-iodised salt intake (OR=0.39), while those for urban residents were age (OR=0.99), terrain (OR=0.83), usual intake of aquatic products (OR=1.24) and non-iodised salt intake (OR=0.27) compared with iodised table salt intake.

CONCLUSIONS

The median urinary iodine concentration of rural residents was higher than that of urban residents although they were both falls in optimal iodine status as recommended by WHO/UNICEF/International Council for the Control of Iodine Deficiency Disorders. Iodised salt intake is the major factor which influences the iodine nutritional status mostly for rural and urban residents. The ongoing monitoring of population iodine status remains crucially important.

Iodine, copper, zinc, selenium and molybdenum levels in children aged between 6 and 12 years in the rural area with iodine deficiency and in the city center without iodine deficiency in Hatay

AIM

Thyroid diseases related with iodine deficiency are observed commonly in our country and in the world. In this study, we aimed to investigate iodine deficiency in urine and selenium, zinc, copper or molybdenum deficiency which may accompany this in children aged between 6 and 12 years in two schools in the province of Hatay (endemic goitre region).

MATERIAL AND METHODS

This study is a case-control field-study in which students aged between 6 and 12 years were included. One hundred fourteen subjects from the village of Tanışma related to the center of our province and 100 subjects from the city center of Hatay (Antakya) were included in the study. Iodine, selenium, zinc, copper and molybdenum levels were measured in the urine samples of the students included in the study.

RESULTS

Iodine deficiency was found with a severe (5%), moderate (18.4%) and mild degree (43%), respectively in the village of Tanışma. Mild iodine deficiency (7%) was found in the center of Hatay. No moderate and severe iodine deficiency was found in the control group. A significant difference was found between the groups in terms of urine iodine excretion (p<0.001). A significant correlation was found between the levels of iodine, selenium, zinc and molybdenum (p<0.05). A moderately positive correlation was found between iodine and selenium (p<0.001). A moderately positive correlation was found between iodine and zinc levels (p<0.001) and a weak correlation was found between iodine and molybdenum (p<0.01). No significant correlation was found between iodine level and copper level (p>0.05).

CONCLUSIONS

Selenium and zinc deficiency may accompany iodine deficiency. Selenium and zinc deficiency should be considered in individuals who are found to have iodine deficiency especially in endemic goitre regions.

Iodized salt consumption in Sudan: present status and future directions

Iodine Deficiency Disorders (IDD) Control Programme in Sudan adopted salt iodization as the long-term strategy in 1994. In 2000, it was found that less than 1% of households were using adequately-iodized salt. The objectives of this study were to: (i) study the coverage and variation of different geographical regions of Sudan regarding access to and use of iodized salt, (ii) explore the possible factors which influence the use of iodized salt, (iii) develop recommendations to help in the implementation of the Universal Salt Iodization (USI) strategy in Sudan. This paper is based on the Sudan Household Health Survey (SHHS) dataset. A total sample of 24,507 households was surveyed, and 18,786 cooking salt samples were tested for iodine levels with rapid salt-testing kits. Nationally, the percentage of households using adequately-iodized salt increased from less than 1% in 2000 to 14.4%, with wide variations between states. Access to iodized salt ranged from 96.9% in Central Equatoria to 0.4% in Gezira state. Population coverage with iodized salt in Sudan remains very low. The awareness and political support for USI programme is very weak. National legislation banning the sale of non-iodized salt does not exist. Utilization of the already-existing laws, like the National Standardization and Metrology Law (2008), to develop a compulsory national salt specification, will accelerate the USI in Sudan.

Iodine status and fish intake of Sudanese schoolchildren living in the Red Sea and White Nile regions

OBJECTIVE

To investigate iodine status and fish consumption of schoolchildren living in the Red Sea and White Nile regions of Sudan.

DESIGN

Cross-sectional study to determine urinary iodine concentration, visible goitre rate, iodine content of salt and fish consumption.

SETTING

Port Sudan (Red Sea) and Jabal Awliya (White Nile), Sudan.

SUBJECTS

Two hundred eighty (n 280) children aged 6-12 years (142 boys, 138 girls).

RESULTS

The median urinary iodine concentration in children from Port Sudan and Jabal Awliya was 553 and 160 μg/l, respectively. Goitre was detected in 17.1 % of children from Port Sudan but only in 1.4 % from Jabal Awliya, The salt samples from Port Sudan contained 150-360 mg iodine (KOI3)/kg salt, whereas those from Jabal Awliya had levels below the detection limit. Despite consuming salt devoid of iodine, children from Jabal Awliya had optimal iodine status. It is plausible that consumption of Nile fish from Jabal Awliya Reservoir, which is a good source of iodine and favoured by the locals, might have provided sufficient iodine. In contrast, children from Port Sudan were at higher risk of iodine-induced hyperthyroidism resulting from consumption of excessively iodised salt.

CONCLUSIONS

The findings of the study clearly demonstrated that (i) Sudan still has a problem with iodine nutrition and quality control and monitoring of salt iodisation and (ii) including fish in the diet could provide a sufficient amount of iodine for schoolchildren.

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.

Single lobe disease in cases of advanced endemic goiter: a new phenotype

OBJECTIVES

To report a new phenotype of advanced endemic goiter that affects only one lobe of the thyroid gland.

PATIENTS AND METHODS

This study included 60 patients from the west of Sudan with long-standing unilateral simple endemic goiter that required obectomy, with emphasis on the gross appearance, measurements and cytological features of the contralateral lobe.

RESULTS

Out of 60 patients with unilateral goiter, 50 (83%) were found to have the disease on the ipsilateral lobe only (monolobar goiter). The contralateral lobe in these 50 patients showed no nodularity, and its volume was within the normal limits. All patients with monolobar disease had total lobectomy on the affected side, and postoperatively they continued to have normal blood levels of T3, T4 and TSH.

CONCLUSION

We report a new phenotype of advanced endemic goiter that affects only one lobe of the thyroid gland, and in the presence of a structurally and functionally normal contralateral lobe.

Epidemiology of thyroid diseases in Africa

BACKGROUND

Thyroid disorders are common endocrine disorders encountered in the African continent. Environmental and nutritional factors are often implicated in the occurrence of some thyroid disorders that occur in this part of the world. This is a narrative review that seeks to document the pattern, prevalence, and management of thyroid disorders in the continent.

MATERIALS AND METHODS

The search engine used for this review were PubMed and Google scholar. All available articles on thyroid disorders from the sub-African continent, published until May 2011, were included.

RESULTS

Iodine deficiency disorders (IDD) which top the list of thyroid disorders and remain the commonest cause of thyroid disorders in the continent is often affected not only by the iodine status in the region but sometimes also by selenium deficiency and thiocyanate toxicity. The reported prevalence rates of endemic goiter range from 1% to 90% depending on the area of study with myxedematous cretinism still a prominent feature of IDD in only a few regions of the continent. The extent of autoimmune thyroid disorders remains unknown because of underdiagnosis and underreporting but the few available studies note a prevalence rate of 1.2% to 9.9% of which Graves diseases is the commonest of these groups of disorders. Rarer causes of thyroid dysfunction such as thyroid tuberculosis and amiodarone related causes are also documented in this review. The onset of new thyroid diseases following amiodarone usage was documented in 27.6% of persons treated for arrhythmia. Reports on thyroid malignancies (CA) in Africa abound and differentiated thyroid malignancies are noted to occur more commonly than the other forms of thyroid CA. The documented prevalence rates of thyroid CA in the African continent are as follows (papillary: 6.7-72.1%, follicular: 4.9-68%, anaplastic: 5-21.4%, and medullary: 2.6%-13.8%). For the differentiated thyroid CA, there is a changing trend toward the more frequent occurrence of papillary CA compared to follicular CA and this may be attributable to widespread iodization programs. Our review shows that diagnosis and evaluation of thyroid disorders are reliant in most regions of the continent on clinical acumen and suboptimal diagnostic facilities and expertise are what obtain in many practices. The frequently employed management options of thyroid disorders in the continent are pharmacological and surgical treatment modalities.

CONCLUSION

Diagnosis and management of thyroid disorders in the African continent remain suboptimal. Thyroid registries may be helpful to determine the scope of the burden of thyroid disorders since this knowledge may help change policies on the approach to the management of these disorders.