Radiation Dose-Response Relationships for Thyroid Nodules and Autoimmune Thyroid Diseases in Hiroshima and Nagasaki Atomic Bomb Survivors 55-58 Years After Radiation Exposure

Department of Clinical Studies, Radiation Effects Research Foundation, Nagasaki, Japan.
JAMA The Journal of the American Medical Association (Impact Factor: 35.29). 04/2006; 295(9):1011-22. DOI: 10.1001/jama.295.9.1011
Source: PubMed

ABSTRACT Effects of irradiation on thyroid diseases such as thyroid nodules and autoimmune thyroid diseases have not been evaluated among people exposed to radiation more than 50 years in the past.
To evaluate the prevalence of thyroid diseases and their radiation-dose responses in atomic bomb survivors.
Survey study comprising 4091 cohort members (mean age, 70 [SD, 9] years; 1352 men and 2739 women) who participated in the thyroid study at the Radiation Effects Research Foundation. Thyroid examinations were conducted between March 2000 and February 2003.
Prevalence of thyroid diseases, including thyroid nodules (malignant and benign) and autoimmune thyroid diseases, and the dose-response relationship of atomic bomb radiation in each thyroid disease.
Thyroid diseases were identified in 1833 (44.8%) of the total participants (436 men [32.2% of men] and 1397 women [51.0% of women]) (P<.001). In 3185 participants, excluding persons exposed in utero, not in the city at the time of the atomic bombings, or with unknown radiation dose, the prevalence of all solid nodules, malignant tumors, benign nodules, and cysts was 14.6%, 2.2%, 4.9%, and 7.7%, respectively. The prevalence of positive thyroid antibodies, antithyroid antibody-positive hypothyroidism, and Graves disease was 28.2%, 3.2%, and 1.2%, respectively. A significant linear dose-response relationship was observed for the prevalence of all solid nodules, malignant tumors, benign nodules, and cysts (P<.001). We estimate that about 28% of all solid nodules, 37% of malignant tumors, 31% of benign nodules, and 25% of cysts are associated with radiation exposure at a mean and median thyroid radiation dose of 0.449 Sv and 0.087 Sv, respectively. No significant dose-response relationship was observed for positive antithyroid antibodies (P = .20), antithyroid antibody-positive hypothyroidism (P = .92), or Graves disease (P = .10).
A significant linear radiation dose response for thyroid nodules, including malignant tumors and benign nodules, exists in atomic bomb survivors. However, there is no significant dose response for autoimmune thyroid diseases.

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Available from: Saeko Fujiwara, Sep 26, 2015
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    • "A transient autoimmune reaction without triggering autoimmune disease and with no effect on thyroid function has been reported in 283 exposed individuals in Belarus 13–15 years after exposure in adolescence to 131 I from Chernobyl fallout (Agate et al. 2008). In atomic bomb survivors exposed to acute gamma radiation (Imaizumi et al. 2006; Morimoto et al. 1987; Nagataki et al. 1994), a convex dose–response association for antibody-positive hypothyroidism was shown (Nagataki et al. 1994), although not confirmed in a more recent and larger study (Imaizumi et al. 2006). More prospective data are required to improve our understanding of the complex relationship between 131 I exposure , TSH concentration or hypothyroidism, and thyroid autoimmunity. "
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    ABSTRACT: Background: Thyroid dysfunction after exposure to low or moderate doses of radioactive iodine-131 (131I) at a young age is a public health concern. However, quantitative data are sparse concerning 131I-related risk of these common diseases. Objective: Our goal was to assess the prevalence of thyroid dysfunction in association with 131I exposure during childhood (≤ 18 years) due to fallout from the Chernobyl accident. Methods: We conducted a cross-sectional analysis of hypothyroidism, hyperthyroidism, autoimmune thyroiditis (AIT), serum concentrations of thyroid-stimulating hormone (TSH), and autoantibodies to thyroperoxidase (ATPO) in relation to measurement-based 131I dose estimates in a Belarusian cohort of 10,827 individuals screened for various thyroid diseases. Results: Mean age at exposure (± SD) was 8.2 ± 5.0 years. Mean (median) estimated 131I thyroid dose was 0.54 (0.23) Gy (range, 0.001–26.6 Gy). We found significant positive associations of 131I dose with hypothyroidism (mainly subclinical and antibody-negative) and serum TSH concentration. The excess odds ratio per 1 Gy for hypothyroidism was 0.34 (95% CI: 0.15, 0.62) and varied significantly by age at exposure and at examination, presence of goiter, and urban/rural residency. We found no evidence of positive associations with antibody-positive hypothyroidism, hyperthyroidism, AIT, or elevated ATPO. Conclusions: The association between 131I dose and hypothyroidism in the Belarusian cohort is consistent with that previously reported for a Ukrainian cohort and strengthens evidence of the effect of environmental 131I exposure during childhood on hypothyroidism, but not other thyroid outcomes.
    Environmental Health Perspectives 05/2013; 121(7). DOI:10.1289/ehp.1205783 · 7.98 Impact Factor
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    • "There was a rise after exposure, and progressive attenuation which is similar to the effects noted after radioiodine therapy in Grave's disease, as will be discussed later [58]. Thyroid autoimmunity and radioiodine did not have a dose-response relationship in a study on Hiroshima and Nagasaki Atomic bomb survivors 60 years after the event [60]. "
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    ABSTRACT: Autoantibodies to thyroglobulin and thyroid peroxidase are common in the euthyroid population and are considered secondary responses and indicative of thyroid inflammation. By contrast, autoantibodies to the TSH receptor are unique to patients with Graves' disease and to some patients with Hashimoto's thyroiditis. Both types of thyroid antibodies are useful clinical markers of autoimmune thyroid disease and are profoundly influenced by the immune suppression of pregnancy and the resulting loss of such suppression in the postpartum period. Here, we review these three types of thyroid antibodies and their antigens and how they relate to pregnancy itself, obstetric and neonatal outcomes, and the postpartum.
    Journal of Thyroid Research 04/2013; 2013(1):182472. DOI:10.1155/2013/182472
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    • "In another study with a cohort of exposed children and adolescents from affected areas of the Ukraine, 0.6% of individuals were found to have hyperthyroidism [9]. Among atomic bomb survivors in Hiroshima and Nagasaki, hyperthyroidism was detected in 1.5% and hypothyroidism in 5.6% of 4,091 participants [7]. Previous studies reported the prevalence of hyperthyroidism and hypothyroidism was 0.1% to 2% for hyperthyroidism and 0.3% to 2% for hypothyroidism in the general population [10], [11], [12]. "
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    ABSTRACT: After the accident at the Chernobyl Nuclear Power Plant (CNPP), the incidence of thyroid cancer increased among children. Recently, a strong relationship between solid thyroid nodules and the incidence of thyroid cancer was shown in atomic bomb survivors. To assess the prognosis of benign thyroid nodules in individuals living in the Zhitomir region of Ukraine, around the CNPP, we conducted a follow-up investigation of screening data from 1991 to 2000 in the Ukraine. Participants of this study were 160 inhabitants with thyroid nodules (nodule group) and 160 inhabitants without thyroid nodules (normal control group) intially identified by ultrasonography from 1991 to 2000. All participants were aged 0 to 10 years old and lived in the same area at the time of the accident. We performed follow-up screening of participants and assessed thyroid nodules by fine needle aspiration biopsy. Among the nodule group participants, the number and size of nodules were significantly increased at the follow-up screening compared with the initial screening. No thyroid nodules were observed among the normal control group participants. The prevalence of thyroid abnormality, especially nodules that could be cancerous (malignant or suspicious by fine needle aspiration biopsy), was 7.5% in the nodule group and 0% in the normal control group (P<0.001). Our study indicated that a thyroid nodule in childhood is a prognostic factor associated with an increase in the number and size of nodules in individuals living in the Zhitomir region of Ukraine.
    PLoS ONE 11/2012; 7(11):e50648. DOI:10.1371/journal.pone.0050648 · 3.23 Impact Factor
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