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. 2009 May;117(5):745-50.
doi: 10.1289/ehp.0800184. Epub 2008 Dec 15.

Subclinical hypothyroidism after radioiodine exposure: Ukrainian-American cohort study of thyroid cancer and other thyroid diseases after the Chornobyl accident (1998-2000)

Evgenia Ostroumova  1 , Alina Brenner, Valery Oliynyk, Robert McConnell, Jacob Robbins, Galina Terekhova, Lydia Zablotska, Ilya Likhtarev, Andre Bouville, Viktor Shpak, Valentin Markov, Ihor Masnyk, Elaine Ron, Mykola Tronko, Maureen Hatch
Affiliations

Subclinical hypothyroidism after radioiodine exposure: Ukrainian-American cohort study of thyroid cancer and other thyroid diseases after the Chornobyl accident (1998-2000)

Evgenia Ostroumova et al. Environ Health Perspect. 2009 May.

Abstract

Background: Hypothyroidism is the most common thyroid abnormality in patients treated with high doses of iodine-131 (131I). Data on risk of hypothyroidism from low to moderate 131I thyroid doses are limited and inconsistent.

Objective: This study was conducted to quantify the risk of hypothyroidism prevalence in relation to 131I doses received because of the Chornobyl accident.

Methods: This is a cross-sectional (1998-2000) screening study of thyroid diseases in a cohort of 11,853 individuals < 18 years of age at the time of the accident, with individual thyroid radioactivity measurements taken within 2 months of the accident. We measured thyroid-stimulating hormone (TSH), free thyroxine, and antibodies to thyroid peroxidase (ATPO) in serum.

Results: Mean age at examination of the analysis cohort was 21.6 years (range, 12.2-32.5 years), with 49% females. Mean 131I thyroid dose was 0.79 Gy (range, 0-40.7 Gy). There were 719 cases with hypothyroidism (TSH > 4 mIU/L), including 14 with overt hypothyroidism. We found a significant, small association between (131)I thyroid doses and prevalent hypothyroidism, with the excess odds ratio (EOR) per gray of 0.10 (95% confidence interval, 0.03-0.21). EOR per gray was higher in individuals with ATPO < or = 60 U/mL compared with individuals with ATPO > 60 U/mL (p < 0.001).

Conclusions: This is the first study to find a significant relationship between prevalence of hypothyroidism and individual (131)I thyroid doses due to environmental exposure. The radiation increase in hypothyroidism was small (10% per Gy) and limited largely to subclinical hypothyroidism. Prospective data are needed to evaluate the dynamics of radiation-related hypothyroidism and clarify the role of antithyroid antibodies.

Keywords: Chernobyl nuclear accident; Chornobyl; dose–response relationship; hypothyroidism; ionizing radiation.

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Figures

Figure 1
Figure 1
Study flow diagram.
Figure 2
Figure 2
Association between prevalence of subclinical hypothyroidism and 131I thyroid dose estimates: Ukrainian–American cohort study of thyroid cancer and other thyroid diseases after the Chornobyl accident, 1998–2000. Dose–response line was adjusted to pass through the lowest 131I dose category. Data points are 131I dose category-specific ORs with 95% CIs. Line represents fitted ORs based on linear EOR model.
See this image and copyright information in PMC

References

    1. Agate L, Mariotti S, Elisei R, Mossa P, Pacini F, Molinaro E, et al. Thyroid autoantibodies and thyroid function in subjects exposed to Chernobyl fallout during childhood: evidence for a transient radiation-induced elevation of serum thyroid antibodies without an increase in thyroid autoimmune disease. J Clin Endocrinol Metab. 2008;93:2729–2736. - PubMed
    1. Andersen S, Bruun NH, Pedersen KM, Laurberg P. Biologic variation is important for interpretation of thyroid function tests. Thyroid. 2003;13:1069–1078. - PubMed
    1. Åsvold BO, Bjøro T, Nilsen TI, Vatten LJ. Tobacco smoking and thyroid function: a population-based study. Arch Intern Med. 2007;167:1428–1432. - PubMed
    1. Belin RM, Astor BC, Powe NR, Ladenson PW. Smoke exposure is associated with a lower prevalence of serum thyroid autoantibodies and thyrotropin concentration elevation and a higher prevalence of mild thyrotropin concentration suppression in the third National Health and Nutrition Examination Survey (NHANES III) J Clin Endocrinol Metab. 2004;89:6077–6086. - PubMed
    1. Bjøro T, Holmen J, Krüger Ø, Midthjell K, Hunstad K, Schreiner T, et al. Prevalence of thyroid disease, thyroid dysfunction and thyroid peroxidase antibodies in a large, unselected population. The Health Study of Nord-Trøndelag (HUNT) Eur J Endocrinol. 2000;143:639–647. - PubMed

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