Goiter rate

Goiter rate, including the rate of palpable or visible goiter classified according to accepted criteria (Anonymous, WHO... 

Humic substances may increase the occurrence of goiter, and the inconsistency in the association between goiter rate and iodine intake may be caused by humic substances. 

In populations with even mild iodine deficiency, an increased goiter rate can be seen. Delange et al. (1997) have measured thyroid volume and urinary iodine excretion in 5709 children aged 7—15 years in different sites in 12 European countries. All ultrasound examinations and urinary iodine assays were performed by the same investigators. An inverse relationship was found (Figure 55.3). 

Since the iodization of salt, there has been an increase in the daily consumption of iodine among the population, leading to a decrease in the prevalence of iodine deficiency disorders. In a survey (Toteja et ai, 2004) carried out on 1 45 264 children aged 6—12 years in 15 districts in India in 1997—2000, the goiter rate was found to have decreased to 4.78% as compared to a previous report of 21% in 1984—1986 (IGMR, 1989). Follow-up surveys carried out in the same region of the country over the period have shown a decrease in the prevalence of goiter over the years, as exemphfied by data from the National Capital Territory of Delhi (Table 87.1). 

However, despite the decrease in the overall goiter rate in India, the prevalence of goiter, albeit at a lower rate, continues. This partial persistence of goiter in the country and its possible causes have been discussed elsewhere in this book. These may include incomplete correction of iodine deficiency, ingestion of goitrogens, or the presence of autoimmune thyroid disease. 

Note Decrease in the prevalence of goiter rate in the National Capital Territory of Delhi after salt iodization. Source Pandav etal., (1980) Sharmaeta/., (1988) Pandavef a/., (1996) Kapil etal., (2004) Gopalakrishnan etal., (2006). 

Suzuki and Mashimo (1973) Observational study Japan Association of increased goiter rates with higher consumption of kelp in coastal districts compared with an inland city decrease in goiter prevalence following reduction in kelp intake... 

The implemented monitoring of iodine deficiency in Bulgaria during the period 1994—2001 assessed on the basis of iodine excretion and goiter rate of representative groups of the population indicated an increase in iodine intake and a decrease in individuals with low iodine intake. On the basis of this indicator the iodine intake of the population after 1994 can be considered as adequate and iodine deficiency successfully controlled (ICCIDD, WHO, UNICEF, 2001 Ivanova 2001). 

Goiter rate among children, schoolchildren and pregnant women exposed to high nitrate levels in drinking water... 

In Minas Gerais, for example, a study showed an endemic mean goiter rate of 44% and identified cretinism, deaf-mutism, and mental retardation in the most affected areas. In Sao Paulo, between 1940 and 1947, 22000 preschool children and adolescents were assessed, and the occurrence of goiter varied from 5 to 10% in the coastal... 

The Department of Health of the Ministry of Public Health is the main office responsible for implementing intervention programs on IDD alleviation. The pilot project for salt iodization was first launched in 1965 in one of the northern districts where the prevalence of goiter rate had been very high. Later in 1968, the salt iodization program was expanded to all affected areas in the country (Figure 126.3). 

Figure 126.8 The decline in total goiter rate in schoolchildren (Nutrition Division, Department of Health, Ministry of Public Health).

Mali is a landlocked country in West Africa, and is one of the poorest countries in the world. Iodine deficiency disorders (IDD) have been prevalent in several areas of the country, especially in the southern part. This chapter provides a historic overview of the changes in IDD over time, and of the various strategies that have been implemented to combat IDD. While the national total goiter rate was estimated to be 30% in 1974, a nationwide survey in 2005 found a total goiter rate of 8%, with 88% of the households using iodized salt. The latest figures indicate that Mali still suffers from iodine deficiency, and that efforts must continue in order to reach the goal of universal salt iodization. 

The endocrine implications of iodine deficiency can be largely discussed with regard to the presence of cretinism, neonatal hypothyroidism, goiter rates, thyroid dysfunction... 

While goiter rates also decline with iodine supplementation, several reports suggest the persistence of endemic prevalence of goiter several years after iodine supplementation. The exact cause for this has yet to be elucidated although an increase in thyroid autoimmunity and the influence of other environmental goitrogens remain possible explanations. 

Thus, the dramatic situation observed by Marandn in 1922 was still present almost 50 years later, despite efforts to improve the socioeconomic situation of the area. Our data showed that iodine deficiency was the most likely cause of the goiter rate, of the low plasma PBI and high plasma TSH, and of the high incidence of cretins, in agreement with data from many other endemias. 

Figure 2.- Frequency distributions for urinary iodine and creatinine, plasma T4, weight and height percentiles, corresponding to 6-12 yrs.-old children from Las Hurdes (Casares, Cabezo, Aceitunillo) and from Miranda del Castaf1ar+ Cepeda, tested by Bleichrodt et al.. Goiter rates were 66 % and 23 %, respectively. indicates P<.001 n.s., P>.05.

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