Iodine deficiency disorder Study

Figure 2 The assessment of total discretionary salt use. (Data from Sanchez-Caslillo CP, Branch WJ, and James WPT (1987) A test for the validity of the lithium-marker technique for monitoring dietary sources of salt in man. Clinical Science 72 87-94 Leclerq C and Ferro-Luzzi A (1991) Total and domestic consumption of salt and their determinants in three regions of Italy. European Journal of Clinical Nutrition 45 151-159 Melse-Boonstra A, Rozendaal M, Rexwinkel H, Gerichhausen MJ, van den Briel T, Bulux J, Solomons NW, and West CE (1998) Determination of discretionary salt intake in rural Guatemala and Benin to determine the iodine fortification of salt required to control iodine deficiency disorders studies using lithium-labeled salt. American Journal of Clinical Nutrition 68 636-641.)...

Melse-Boonstra A, Rozendaal M, Rexwinkel H, Gerichhausen MJ, van den Briel T, Bulux J, Solomons NW, and West CE (1998) Determination of discretionary salt intake in rural Guatemala and Benin to determine the iodine fortification of salt required to control iodine deficiency disorders studies using lithium-labeled salt. American Journal of Clinical Nutrition 68 636-641. 

As iodine intake is an important up- or downregulator of the activity of the normal thyroid gland, the iodine intake of a population should be brought to the level at which iodine deficiency disorders are avoided (Laurberg et al., 2000). Thyroid dysfunction is known to be more common in women than in men. The frequency of thyroid abnormalities has been reported in several Norwegian studies... 

Healthcare Service Delivery in Achieving Sustained Elimination of Iodine Deficiency Disorders A Case Study, China... 

In order to combat the prevalence of iodine deficiency disorders, the World Health Organization has recommended that all food salt should be iodized (WHO, 1999), although compliance with this varies. Salt sold in Canada for table use must be iodized according to federal law. The proportion of households using iodized salt is lowest in Europe at 27% compared with 90% in the US (WHO, 1999). The UK has a diet sufficient in iodine, and salt is not routinely supplemented with iodine. There are only trace levels of iodine in noniodized salt, which is therefore entirely safe within a low-iodine diet. Studies testing levels of iodine in sea and rock salt have found only trace levels of iodine (Aquaron, 2000). In one comparison 1.2—1.4p,g iodine/g of noniodized sea salt compared with 52.9— 84.6 rg iodine/g of iodized salt (Fisher, 1980). However, due to the significant quantity of iodine in seawater a common misconception exists that sea salt is also rich in iodine. 

Iodine Nutrition in Bulgaria Results from the National Strategy for Elimination of Iodine Deficiency Disorders in Bulgaria -Epidemiologic Studies on Risk Population Groups... 

The recently completed Australian National Iodine Nutrition Study was designed to obtain a snapshot of urinary iodine levels and thyroid size in 8—10-year-old Australian schoolchildren (Li et al., 2006a). The study was organized and carried out between 2003 and 2004 by the Australian Centre for Control of Iodine Deficiency Disorders (ACCIDD) situated in Westmead Hospital and the Faculty of Medicine of the University of Sydney. Children between 8 and 10 years of age were randomly selected from schools in five of the six states of Australia. Tasmanian children were excluded from the study because the voluntary iodized bread program had already commenced in that state. Using the ThyroMobil kindly provided by the Merck pharmaceutical company, approximately 1800 children underwent ultrasound examination for thyroid volume and provided urine specimens for urinary iodine levels. Median urinary iodine levels varied from one state to another, with the national median level being just under 100 pg/1, which is consistent with mild... 

All this activity has stemmed from a new perception of the effects of iodine deficiency. The concept of the Iodine Deficiency Disorders refers to a broad spectrum of conditions which affect the fetus, the neonate, the child and the adult. Particularly important are the fetal effects, including miscarriage, stillbirth, as well as neurological cretinism which is of special interest to this symposium, as it is the reference point for studies on iodine and the brain. This condition, well known in the ancient and mediaeval worlds, was described in Diderot s Encyclopedie in 1754 when a cretin was defined as an "imbecile with a goitre down to the waist". 

Iodine Deficiency Disorders (IDD) are a major international public health problem (1). The effects of iodine deficiency occur at all ages, but are particularly important during the period of fetal development. The available epidemiological evidence has been complemented by experimental studies of fetal development in animal models. These have focussed particularly on fetal brain development because of its obvious importance Definite effects have been observed in a variety of animal models - the rat, the marmoset and the sheep. In addition studies of the mechanisms involved have been carried out which have revealed the importance of maternal thyroid function for fetal brain development. 

This is a study of the long-term effects of administration of Iodized oil in two Andean rural communities Tocachi and La Esperanza. This program of prophylaxis was started in March 1966 ( ) At that time these two neighboring villages were similar in terms of isolation, ethnic composition, degree of iodine deficiency, and socioeconomic conditions (protein-calorie malnutrition, annual income per capita, cultural deprivation, etc.) They presented similar prevalences of iodine deficiency disorders. 

These studies indicate the large dimension of the brain component in the iodine deficiency disorders. 

Could I ask Dr. Chambon whether the results of your animal studies can be extrapolated to the human species, in particular the implication for the treatment of iodine deficiency disorders ... 

Based on such evidence on iodine-induced disease in individual patients, it would be expected that an increase in population iodine intake would lead to an increase in the incidence and prevalence of certain thyroid disorders. To evaluate this in more detail, and to obtain information on the level of iodine intake where such an increase will take place, epidemiological studies are necessary. As shown in Table 47.1 there is evidence to suggest that a number of abnormalities may be more common when iodine intake becomes high. However, in general the evidence is less strong, compared with the evidence for less disease with eradication of iodine deficiency (Table 47.1), and the sum of burdens is lower (Figure 47.1). 

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