A cross-section analysis of FT3 age-related changes in a group of old and oldest-old subjects, including centenarians’ relatives, shows that a down-regulated thyroid function has a familial component and is related to longevity

Background: several studies suggest that a decreased thyroid activity might be favourable in oldest-old subjects and that subclinical thyroid hyperfunction may be detrimental

Myocardial ultrasonic tissue characterization in patients with thyroid dysfunction

<p>Abstract</p> <p>Background</p> <p>Structural myocardial abnormalities have been extensively documented in hypothyroidism. Experimental studies in animal models have also shown involvement of thyroid hormones in gene expression of myocardial collagen. This study was planned to investigate the ability of ultrasonic tissue characterization, as evaluated by integrated backscatter (IBS), to early identify myocardial involvement in thyroid dysfunction.</p> <p>Patients and Methods</p> <p>We studied 15 patients with hyperthyroidism (HYPER), 8 patients with hypothyroidism (HYPO), 14 patients with subclinical hypothyroidism (SCH) and 19 normal (N) subjects, who had normal LV systolic function. After treatment, 10 HYPER, 6 HYPO, and 8 SCH patients were reevaluated. IBS images were obtained and analyzed in parasternal short axis (papillary muscle level) view, at left ventricular (LV) posterior wall. The following IBS variables were analyzed: 1) the corrected coefficient (CC) of IBS, obtained by dividing IBS intensity by IBS intensity measured in a rubber phantom, using the same equipment adjustments, at the same depth; 2) cardiac cyclic variation (CV) of IBS - peak-to-peak difference between maximal and minimal values of IBS during cardiac cycle; 3) cardiac cyclic variation index (CVI) of IBS - percentual relationship between the cyclic variation (CV) and the mean value of IBS intensity.</p> <p>Results</p> <p>CC of IBS was significantly larger (p < 0.05) in HYPER (1.57 ± 0.6) and HYPO (1.53 ± 0.3) as compared to SCH (1.32 ± 0.3) or N (1.15 ± 0.27). The CV (dB) (HYPO: 7.5 ± 2.4; SCH: 8.2 ± 3.1; HYPER: 8.2 ± 2.0) and the CVI (HYPO: 35.6 ± 19.7%; SCH: 34.7 ± 17.5%; HYPER: 37.8 ± 11.6%) were not significantly different in patients with thyroid dysfunction as compared to N (7.0 ± 2.0 and 44.5 ± 15.1%).</p> <p>Conclusions</p> <p>CC of IBS was able to differentiate cardiac involvement in patients with overt HYPO and HYPER who had normal LV systolic function. These early myocardial structural abnormalities were partially reversed by drug therapy in HYPER group. On the other hand, although mean IBS intensity tended to be slightly larger in patients with SCH as compared to N, this difference was not statistical significant.</p

[Epidemiology of endemic goiter in Italy].

Epidemiological surveys on goiter endemia carried out in Italy in the two last decades were recently reviewed. Iodine deficiency and endemic goiter were documented in the entire country. In recent studies, urinary iodine excretion was higher and prevalence of goiter was lower than that documented in the past, in absence of a national program of prophylaxis. Nevertheless, in a recent study carried out in Basilicata, in schoolchildren a goiter prevalence of 16% was documented. In conclusion, iodine deficiency and endemic goiter are still present in Italy; despite the beneficial effects of "silent prophylaxis", a iodine prophylaxis program is mandatory

[Multinodular goiter. Epidemiology and prevention].

Nodular goiter is the natural evolution of nontoxic goiter, that may be endemic, sporadic or familiar. Iodine deficiency is the cause of endemic goiter, while genetical defects, impairing the thyroid hormone biosynthetic efficiency or altering the number and/or activity of growth factor receptors, play the major role in the pathogenesis of sporadic and familiar nontoxic goiter. The prevalence of nodular goiter is directly related to the degree of iodine deficiency that is still present in several areas of the world. In iodine deficient areas such as some Italian regions, nodular goiter is present in 25-33% of the population, its frequency increasing with age. In iodine sufficient areas the prevalence of nodular goiter is comprised between 0.4 and 7.2% high in iodine deficient areas and about 4% in iodine sufficient countries, its frequency increasing with the age. Dysphagia, dyspnea and coarsening of the voice may occur for esophagous, tracheal or laryngeal nerve compression, respectively. Iodine deficiency has little if any effect on the frequency of thyroid carcinoma, while, with regard to the histological pattern, it leads to an increased ratio papillary/follicular. Thyroid function is normal in uncomplicated nontoxic goiter. However, the evolution of nodular goiter is toward the functional autonomy of nodules that may result in thyrotoxicosis. Hypothyroidism is rare and is usually the result of thyroid autoimmunity. All the cases due to iodine deficiency can be prevented by an adequate iodine prophylaxis that can be accomplished in industrialized countries by the use of sale enriched in iodine

[Efficacy and safety of iodine prophylaxis].

Iodine deficiency and iodine deficiency disorders (IDD) are still present in developing countries as well as in some European areas. It is well known that iodine deficiency correction prevents endemic goiter and other IDD. Iodized oil has been shown to reduce goiter prevalence and cretinism in African countries. In countries where iodine prophylaxis is performed since many years (USA, Switzerland, Scandinavian countries) IDD are dramatically reduced. One example of the efficacy of iodine prophylaxis through iodized salt was reported in a Tuscan village were urinary iodine excretion increased from 47 micrograms/l in 1981 to 130 micrograms/l in 1991. Goiter prevalence in schoolchildren dropped from 60% in 1981 to 8.1% in 1991. In the same children neuropsychological performances were evaluated showing a reduction of motor response to perceptive stimuli assessed by measurement of reaction times in children born before the beginning of iodine prophylaxis. Iodine prophylaxis has no side effects, although a transitory increase of hyperthyroidism has been reported in the past and recently in African countries. A reevaluation by the experts of the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) has pointed out that this phenomenon is not relevant with respect to the efficacy of iodine prophylaxis. In conclusion, universal iodine prophylaxis prevents endemic goiter and other IDD, without side effects

Iodine deficiency disorders in Europe.

Iodine deficiency disorders (IDD) are related to the degree of iodine deficiency. In European countries, characterized by mild to moderate iodine deficiency, neurological deficits or minor neuropsychological impairments have been described. Urinary iodine excretion (UIE) ranged from 30 to 170 mcg/L, 141 millions of people were at risk of IDD, 97 millions were affected by goiter and 0.9 millions had an impaired mental development. Iodine prophylaxis is devoid of adverse reactions with the exception of sporadic cases of transitory hyperthyroidism, associated to the severity of iodine deficiency before the prophylaxis. The International Council for Control of IDD recommends an universal iodine prophylaxis, instituted gradually in severe iodine deficient countries. The total cost of universal iodine prophylaxis is very cheap compared to the social cost of goiter and cretinism. In conclusion, most European countries are still characterized by mild to moderate iodine deficiency. Iodine prophylaxis programs are already operating, its cost is irrelevant with respect to the undebatable beneficial impact on the health. Adverse effects are not observed except in severe iodine deficient areas where iodine intake was abruptly increased