RESUMEN
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 612 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 Clâ», Fâ», Ca²âº, Mg²âº and total hardness of drinking water. SUBJECTS: Schoolchildren (n 654) aged 612 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 46,4µg/dl. Out of thirty-one pupils from Port Sudan, twenty-four (77.42 %) were found to have urinary iodine concentration greater than 30µg/dl and twelve (38.71 %) had different degrees of biochemical hypothyroidism. Excessive concentrations of Clâ», Ca²âº, Mg²âº and water hardness (369.2, 116.48, 60.21 and 539.0mg/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.
Asunto(s)
Agua Potable/química , Bocio Endémico/epidemiología , Hipotiroidismo/etiología , Yodo/administración & dosificación , Estado Nutricional , Glándula Tiroides/patología , Biomarcadores/sangre , Calcio/análisis , Niño , Cloruros/análisis , Estudios Transversales , Bocio Endémico/sangre , Bocio Endémico/orina , Dureza , Humanos , Hipotiroidismo/sangre , Hipotiroidismo/epidemiología , Hipotiroidismo/orina , Yodo/orina , Magnesio/análisis , Prevalencia , Sudán/epidemiologíaRESUMEN
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.