Epidemiološki trendi bolezni ščitnice, ki so povezane z jodom: primer Slovenije

The epidemiology of thyroid disorders is significantly associated with iodine supply. In 1999, Slovenia increased iodine content in kitchen salt from 10 mg to 25 mg of potassium iodide per kg of salt. According to the WHO criteria, Slovenia shifted from a mildly iodine-deficient country to a country with adequate iodine intake. Ten years after the increase in iodine intake, the incidence of diffuse goitre and thyroid autonomy decreased. Now patients with diffuse goitre and thyroid autonomy reach older age than the patients before the increase in iodine intake. In addition, patients with thyroid autonomy are less frequently hyperthyroid than ten years ago and iodine-induced hyperthyroidism is less severe. The incidence of highly malignant thyroid carcinoma has also dropped. However, the incidence of Hashimoto’s thyroiditis increased, most probably in genetically predisposed individuals. Over the last ten years, many animal and in vitro studies evaluated the effects of endocrine disrupting chemicals (EDC) on various aspects of the thyroid function. They mostly studied the effects of polychlorinated biphenyls (PCBs) and dioxins, brominated flame retardants, phthalates, bisphenol A, perfluorinated chemicals, and perchlorate. However, human studies on the effects of EDCs on the thyroid function are very scarce, especially the long-term ones. What they do suggest is that PCBs and dioxins interfere with the transport of thyroid hormones and adversely affect the thyroid function. Many authors agree that iodine deficiency predisposes the thyroid gland to harmful effects of EDCs. Therefore the effects of EDCs in iodine-deficient areas could be more severe than in areas with adequate iodine intake.Epidemiologija bolezni ščitnice je pomembno povezana z jodno preskrbo. V Sloveniji smo leta 1999 zvečali vsebnost joda v kuhinjski soli z 10 mg na 25 mg kalijevega jodida na kg soli. Glede na kriterije SZO smo se iz države z blagim pomanjkanjem joda spremenili v državo z ustreznim vnosom joda. Ugotovili smo, da se je v desetih letih po zvečanju jodne preskrbe zmanjšala pojavnost difuzne golše in avtonomnega tkiva v ščitnici. Bolniki z difuzno golšo in avtonomnim tkivom so sedaj starejši kot pred zvečanjem jodne preskrbe. Poleg tega so bolniki z avtonomnim tkivom redkeje hipertirotični kot pred desetimi leti, hipertiroza, ki je posledica čezmernega vnosa joda, pa je manj izražena. Zmanjšala se je pojavnost najbolj maligne oblike ščitničnega karcinoma. Povečala se je pojavnost Hashimotovega tiroiditisa, verjetno pri genetsko predisponiranih posameznikih. V zadnjem desetletju so v številnih raziskavah na živalih in v raziskavah in vitro ugotavljali vpliv kemijskih povzročiteljev hormonskih motenj (KPHM) na različne vidike ščitnične funkcije. Najpogosteje testirani KPHM so bili poliklorirani bifenili (PCB) in dioksini, bromirani zaviralci gorenja, ftalati, bisfenol A, perfluorirane kemikalije in perklorat. Vendar pa so raziskave o učinkih KPHM na delovanje ščitnice pri ljudeh, zlasti dolgoročne raziskave, zelo redke. Zdi se, da zlasti PCB in dioksini vplivajo na transport ščitničnih hormonov in negativno učinkujejo na delovanje ščitnice. Številni avtorji menijo, da pomanjkanje joda poveča dovzetnost ščitnice za škodljive učinke KPHM. Torej bi lahko bili škodljivi učinki KPMH na področjih pomanjkanja joda resnejši kot na področjih zadostnega vnosa joda

Hashimoto's Thyroiditis: From Genes to the Disease

Hashimoto’s thyroiditis (HT) is the most prevalent autoimmune thyroid disorder. Intrathyroidal lymphocytic infiltration is followed by a gradual destruction of the thyroid gland which may lead to subclinical or overt hypothyroidism. Biochemical markers of the disease are thyroid peroxidase and/or thyroglobulin autoantibodies in the serum which are present with a higher prevalence in females than in males and increase with age. Although exact mechanisms of aetiology and pathogenesis of the disorder are not completely understood, a strong genetic susceptibility to the disease has been confirmed predominantly by family and twin studies. Several genes were shown to be associated with the disease occurrence, progression, and severity. Genes for human leukocyte antigen, cytotoxic T lymphocyte antigen-4, protein tyrosine phosphatase nonreceptor-type 22, thyroglobulin, vitamin D receptor, and cytokines are considered to be of utmost importance. Amongst endogenous factors for the disease development, the attention is focused predominantly on female sex, pregnancy with postpartum period and fetal microchimerism. Environmental factors influencing HT development are iodine intake, drugs, infections and different chemicals. Disturbed self-tolerance accompanied by the increased antigen presentation is a prerequisite for the HT occurrence, whereas proper interaction of thyroid cells, antigen presenting cells, and T cells are necessary for the initiation of thyroid autoimmunity. Secreted cytokines lead predominantly to T-helper type 1 (Th1) response as well as to Th 17 response which has only recently been implicated. Final outcome of HT is thyroid destruction which is mostly a consequence of the apoptotic processes combined with T-cell mediated cytotoxicity

Ten-year follow-up of thyroid epidemiology in Slovenia after increase in salt iodization

Aim To assess iodine supply and follow thyroid epidemiology for ten years after an iodine increase from 10 to 25 mg of potassium iodide per kilogram of salt in 1999. Methods In 2002 and 2003, we determined the thyroid size by palpation and ultrasound and measured urinary iodine concentration (UIC) in 676 schoolchildren from 34 schools throughout Slovenia. From 1999 to 2009, we followed the incidence of diffuse and nodular goiter, thyroid autonomy, Graves’ disease, and Hashimoto’s thyroiditis among adults in the stable catchment area of the University Medical Centre Ljubljana with 1 000 000 inhabitants. Results In children, only 1% had a goiter grade 2 (visible and palpable thyroid gland), median thyroid volume was 5.8 mL, and median UIC was 148 μg/L. In adults, the incidence of diffuse goiter and thyroid autonomy decreased significantly (2009 vs 1999, rate ratio [RR], 0.16; 95% confidence interval [CI], 0.12-0.21 and RR, 0.73; 95% CI, 0.62- 0.86, respectively), with a lower incidence in younger participants in 2009 (P < 0.001). The incidence of multinodular goiter and solitary nodule increased (2009 vs 1999, RR, 1.55; 95% CI, 1.35-1.79 and RR, 1.72; 95% CI, 1.49-1.99, respectively). No long-term changes were observed for Graves’ disease (2009 vs 1999, RR, 0.95; 95% CI, 0.81-1.13), while the incidence of Hashimoto’s thyroiditis increased strongly (2009 vs 1999, RR, 1.86; 95% CI, 1.64-2.12). Conclusions The change from mildly deficient to sufficient iodine supply was associated with a marked change in the incidence of thyroid epidemiology – a significant decline in the incidence of diffuse goiter and thyroid autonomy and a marked increase in the incidence of Hashimoto’s thyroiditis

Hypothyroidism is associated with higher testosterone levels in postmenopausal women with Hashimoto's thyroiditis

Introduction: There are few data about possible interaction of sex hormones and thyroid autoimmunity and function in women with Hashimoto’s thyroiditis (HT) after menopause. Therefore, our aim was to investigate sex hormone levels in euthyroid (EuHT) and hypothyroid (HypoHT) postmenopausal women with HT. Material and methods: We performed a prospective observational clinical study that included 55 women with HT (AllHT) and 18 healthy subjects (HS) after menopause matched by age, body mass index, follicle-stimulating hormone, and menopause duration. According to their thyrotropin (TSH) level, the AllHT patients were divided into two subgroups: EuHT with TSH in the range 0.35–5.5 mU/L and HypoHT with TSH above 5.5 mU/L. Total and free testosterone (T), sex hormone-binding globulin (SHBG), oestradiol (E2), and progesterone (P) were measured in all subjects. Values are presented as mean ± SD. The Mann-Whitney U test was used for comparison of values between the groups. Correlations were tested using Kendall’s tau test. Results: In the HypoHT group, significantly higher free T levels were found in comparison to the HS group (7.89 ± 3.55 pmol/L and 7.13 ± 3.03 pmol/L, p &lt; 0.05). Furthermore, in HypoHT, free T was significantly higher than in EuHT (7.19 ± 5.65 pmol/L, p &lt; 0.05). SHBG was significantly lower in HypoHT compared with HS (45.4 ± 17.4 nmol/L and 60.09 ± 19.51 nmol/L, p &lt; 0.05). No significant correlation was found between sex hormone levels and thyroglobulin and thyroid peroxidase antibodies. Conclusion: We report significantly higher free and total T levels in hypothyroid postmenopausal women with HT. To our knowledge, this is the first study of sex hormone levels in postmenopausal women with HT.

Efficacy and safety of a 30-day methylprednisolone treatment protocol for subacute thyroiditis: a prospective study

Objective: The optimal corticosteroid treatment regimen for subacute thyroiditis has not yet been established. To avoid side effects, tapering of the initial dose of corticosteroid is recommended. With reducing dose, the symptoms can recur. Design: In a prospective clinical study, a 30-day methylprednisolone (MPSL) treatment protocol with a starting dose of 24 mg/day and tapered by 4 mg every 5 days was assessed for effectiveness and safety regarding possible adrenal insufficiency. Methods: Fifty-nine patients with subacute thyroiditis were included. At visit 1, after establishing the diagnosis, a short stimulation adrenocorticotrophic hormone (ACTH) test was performed and methylprednisolone treatment was prescribed. At visit 2 (40 ± 5 days after visit 1), clinical, laboratory (including short stimulation ACTH test), and ultrasound evaluation were repeated. Results: Forty-eight patients (81.4%) were cured by the prescribed protocol, having significantly lower cortisol levels after stimulation at visit 1 than patients who were not cured (mean, 674.9 nmol/L and 764.0 nmol/L, respectively, P = 0.012). Seven patients (12.3%) developed adrenal insufficiency; this group had significantly lower cortisol levels after stimulation at visit 1 than patients without adrenal insufficiency development (mean, 561.5 nmol/L and 704.7 nmol/L, respectively, P = 0.005). Using stimulated cortisol level at visit 1 as the explanatory variable, logistic models were optimized to determine treatment efficacy (AUC = 0.745, optimal threshold 729 nmol/L, specificity 71%, sensitivity 73%) and adrenal function (AUC = 0.861, optimal threshold 629 nmol/L, specificity 73%, sensitivity 100%). Conclusions: The described protocol was efficient for more than 80% of patients. Using this protocol, the corticosteroid treatment interval is shorter than proposed in current guidelines. Significance statement: A short but effective protocol for treatment of subacute thyroiditis with methylprednisolone is presented in this article. Using this protocol, the treatment interval is shorter than proposed in current guidelines. Its safety regarding possible adrenal insufficiency is assessed

Posodobljena priporočila diagnostike in zdravljenja diferenciranega raka ščitnice

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