Search

Endemic cretinism is still present in an endemic goiter area of the central Apennines (Montefeltro) (goiter prevalence 55%; mean urinary iodine level 39 micrograms/g creatinine). Clinical and biochemical features of patients with myxedematous, neurologic, and mixed cretinism were studied. Also, in this area, as in most other, neurologic cretinism is more prevalent than myxedematous and mixed forms. The hormonal profiles of the three types of cretinism were clearly different. Nevertheless, all myxedematous cretins had some neurologic disorders (hyperreflexia, increased muscle tone, disorder of gait, Babinski sign, hypoacusia) that were similar to those present in neurologic cretins. These findings suggest that neurologic damage is very similar in all forms of endemic cretinism, reflecting a diffuse insult to the developing fetal nervous system. Furthermore, these data support the hypothesis that the primary pathophysiologic event in the different types of endemic cretinism is represented by maternal and fetal hypothyroidism, while differences may be explained by the extent and duration of postnatal hypothyroidism. All the cretins were over 35 of age, suggesting a severe iodine deficiency in the past decades, and a progressive improvement of nutritional status resulted in "silent iodine prophylaxis." However, recent studies have revealed the persistence of a moderate iodine deficiency, a high prevalence of neurologic hypoacusia, and reduction of mental performance in normal schoolchildren of this area. These findings constitute strong evidence in favor of adequate iodine prophylaxis.

We have evaluated neuropsychic development in 70 normal schoolchildren in an area of severe endemic goitre and cretinism in the Central Apennines (Montefeltro). In each subject we have studied auxological, psychometric and audiometric parameters, together with tympanograms and stapedial reflexograms. Auxological data were in the normal range, as were the stapedial reflexograms and tympanograms. On the contrary, 54.8% of the sample performed below the 25th percentile in psychometric tests (Raven test PM-47), being also 22.8% below the 5th percentile. Audiometric data showed a neurological hearing impairment in 3.1% of the children tested, as compared with 0.28% in the area of Pisa. These data point out that an impairment of central nervous system function still persists in this area of severe endemic goitre.

The goitrogenic role of autoimmune phenomena in endemic goiter is still uncertain. Scanty and discrepant results have been reported in different areas of the world. This prompted us to evaluate the prevalence of circulating thyroid antibodies in an area of North-Western Tuscany during a survey for endemic goiter. The survey was carried out according to the P.A.H.O. criteria in a stable community. In all schoolchildren (n = 142, age range 7-15 yr) and in most of their parents (n = 159), thyroid size was evaluated and urine was collected for iodine determination. Blood was drawn for determination of circulating thyroid microsomal (MAb) and thyroglobulin antibodies (TgAb), TT3, TT4 and TSH. Prevalence of goiter in schoolchildren was 77.9% and 94.8% in their parents. Mean (+/- SD) urinary iodine excretion was 55.0 +/- 2.1 micrograms/24 h. The overall frequency of TgAb and MAb in the adult population was 14.4%, statistically higher than that of control subjects matched for sex and age. The frequency in schoolchildren was 4.3%. The presence of goiter in children was unrelated to the presence of thyroid antibodies in parents, whether goitrous or nongoitrous. A higher prevalence of goiter was found in children with goitrous parents as compared to children with nongoitrous parents (p less than 0.005). In conclusion, the frequency of thyroid autoantibodies in the adult population of the endemic area studied was increased, but showed no relation with the presence of goiter. The prevalence of goiter in children was associated with the presence of goiter but not of thyroid autoantibodies in parents. These data suggest that autoimmune phenomena are of limited importance in the development of endemic goiter.

Subjects living in iodine deficient areas were reported to have elevated serum thyroglobulin (Tg) concentrations. This finding was interpreted as related to thyroid stimulation. Discrepant results, however, were found when serum Tg concentrations were correlated either with serum TSH or with goitre size. In this study we investigated the relationships between goitre size, serum Tg and serum TSH in 488 unselected adult subjects living in an endemic area of North-Western Tuscany (Garfagnana district). The control group comprised 352 subjects residing in a non-endemic area. In the endemic area a high prevalence of goitre was found (80.1%), thyroid enlargement being slight to moderate in the majority of cases and very large only in six subjects. Serum Tg concentrations increased and serum TSH levels decreased with the size of goitre. Statistical analysis by the chi-square cross correlation test showed that the converse changes of serum Tg and serum TSH in relation to goitre size were highly significant. These findings indicate that the increase of serum Tg occurring in endemic goitrous subjects may be related to factors other than TSH stimulation. Functional autonomy of the thyroid may account for the finding of low serum TSH and elevated serum Tg values in patients with large goitres. The present data do not exclude the possibility that the release of Tg is influenced by TSH stimulation, but indicate that other factors may be responsible for the increased levels of Tg found in endemic goitre.

Background:The aims of the study were: (i) to determine iodine status of schoolchildren living in northeast Italy; (ii) to assess dietary habits and iodine status and (iii) to investigate the level of knowledge concerning iodine sufficiency and ways to ameliorate iodine status.Methods:One thousand three hundred seventy-five consecutive 12-13 year-old completed questionnaires collecting demographic data and information about the use of iodized salt and food frequency habits. Iodine concentration in urine samples (UIC) and in commercially available milk samples has been measured.Results:The median UIC was found to be 81 μg/l (95% confidence interval (CI) 74-87); 40% of the subjects had an UIC of 100 μg/l. Iodine deficiency was prevalent in subjects living in hilly areas. Median iodine concentration in milk was 264 μg/l. Only the combined use of iodized salt plus daily milk normalized UIC, resulting into a median value of 108 μg/l. A logistic regression model confirmed independent associations between low UIC and low intake of milk, use of non-iodized salt and geographical location (P<0.0001). Only 45% of the subjects were aware of the importance of iodine.Conclusions:Northeast Italy is still characterized by mild iodine deficiency. An adequate iodine status was achieved only when iodized salt was combined with daily milk intake. The national iodine prophylaxis program has led to greater consumption of iodized salt and, it is now used in 60-70% of the Italian households. The low level of awareness highlights the need for public programs to promote knowledge and efforts to improve iodine status. [ABSTRACT FROM AUTHOR]