title: Iodinated Contrast Medium Exposure During Computed Tomography Increase the Risk of Subsequent Development of Thyroid Disorders in Patients Without Known Thyroid Disease: A Nationwide Population-Based, Propensity Score-Matched, Longitudinal Follow-Up Study.
abstract: To investigate the association between iodinated contrast medium (ICM) exposure during computed tomography (CT) and the subsequent development of thyroid disorders in patients without known thyroid disease in Taiwan, an iodine-sufficient area. We conducted a population-based cohort study by using data from 1996 to 2012 in the Taiwan National Health Insurance Research Database. A total of 33,426 patients who underwent ICM-enhanced CT were included as the study cohort. To avoid selection bias, we used propensity score and matched for the index year (defined as the year of first ICM exposure) to retrieve 33,426 patients as the comparison cohort. No patients in the 2 cohorts had any known thyroid disease before the index year. Patients with a history of amiodarone treatment or coronary angiography and those with <1 year follow-up were excluded. Participants were followed until a new diagnosis of thyroid disorder or December 31, 2011. Hazard ratios (HRs) with 95% confidence interval (95% CI) were calculated using the Cox proportional hazards regression. An association was identified between ICM exposure and the subsequent development of thyroid disorders after adjustment for potential confounders (adjusted HR = 1.17; 95% CI: 1.07-1.29; P = 0.001). Male patients and patients' ages ≥40 years in the ICM-exposure cohort had a higher adjusted HR for developing thyroid disorders than did those in the non-ICM-exposure cohort. Hypothyroidism had the highest adjusted HR (HR = 1.37; 95% CI: 1.06-1.78; P < 0.05) among all thyroid disorders and had a higher risk of development or detection during >0.5-year post-ICM exposure compared with that during ≤0.5-year post-ICM exposure (HR = 1.26; 95% CI: 1.01-1.58; P < 0.05). Repeated ICM exposure increased the risk of thyroid disorders in patients who accepted >1 time of ICM per year on average compared with those who accepted ≤1 time per year on average (adjusted HR = 3.04; 95% CI: 2.47-3.73; P < 0.001). This study identified ICM exposure during CT as a risk factor for the subsequent development of thyroid disorders in patients without known thyroid disease, particularly in patients with repeated exposure.
authors.affiliation: From the Department of Emergency Medicine, Taipei Veterans General Hospital, Taoyuan Branch, Taoyuan, Taiwan, R.O.C. (M-SH); Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, R.O.C. (M-SH); School of Medicine, National Yang-Ming University, Taipei, Taiwan, R.O.C. (M-SH, C-SC, S-YL); Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan, R.O.C. (M-SH); Department of Dermatology (C-SC), Center for Geriatrics and Gerontology, Taichung Veterans General Hospital, Taichung, Taiwan, R.O.C. (S-YL), Department of Radiology (M-YL), Department of Education and Research (C-SC, M-LS), and Department of Emergency Medicine (S-YH), Taichung Veterans General Hospital, Taichung, Taiwan, R.O.C.; Rong Hsing Research Center for Translational Medicine (C-SC, M-LS) and Institute of Biomedical Sciences (C-SC, M-LS), National Chung Hsing University, Taichung, Taiwan, R.O.C.; Department of Medicinal Botanicals and Health Applications, Da-Yeh University, Changhua, Taiwan, R.O.C. (C-SC, S-LC); Department of Cosmetic Science, Providence University, Taichung, Taiwan, R.O.C. (C-SC); Graduate Institute of Integrated Medicine, College of Chinese Medicine, Research Center for Chinese Medicine and Acupuncture (W-CC, J-HC), College of Medicine (J-HC), and Management Office for Health Data (J-HC), China Medical University, Taichung, Taiwan, R.O.C.; Sex Hormone Research Center, Departments of Obstetrics and Gynecology, Urology, and Medical Research (W-CC) and Department of Medical Research, Obstetrics and Gynecology, Dermatology, and Urology (W-CC), China Medical University Hospital, Taichung, Taiwan, R.O.C.; School of Medicine (S-YH) and Institute of Medicine (S-YH), Chung Shan Medical University, Taichung, Taiwan, R.O.C.; Department of Nursing, College of Health, National Taichung University of Science and Technology, Taichung, Taiwan, R.O.C. (S-YH).
authors.forename: Ming-Shun
authors.initials: MS
authors.lastname: Hsieh
authors.forename: Chien-Shan
authors.initials: CS
authors.lastname: Chiu
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Chen
authors.forename: Jen-Huai
authors.initials: JH
authors.lastname: Chiang
authors.forename: Shih-Yi
authors.initials: SY
authors.lastname: Lin
authors.forename: Meng-Yu
authors.initials: MY
authors.lastname: Lin
authors.forename: Shih-Liang
authors.initials: SL
authors.lastname: Chang
authors.forename: Meei-Ling
authors.initials: ML
authors.lastname: Sheu
authors.forename: Sung-Yuan
authors.initials: SY
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000009:adverse effects*; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007348:Insurance, Health; D017613:Iodine Compounds / Q000009:adverse effects*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D013624:Taiwan / Q000453:epidemiology; D013959:Thyroid Diseases / Q000453:epidemiology*; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D017613:Iodine Compounds