Di Teng1, Wenqing Yang1, Xiaoguang Shi1, Yongze Li1, Jianming Ba2, Bing Chen3, Jianling Du4, Lanjie He5, Xiaoyang Lai6, Yanbo Li7, Haiyi Chi8, Eryuan Liao9, Chao Liu10, Libin Liu11, Guijun Qin12, Yingfen Qin13, Huibiao Quan14, Bingyin Shi15, Hui Sun16, Xulei Tang17, Nanwei Tong18, Guixia Wang19, Jin-An Zhang20, Youmin Wang21, Yuanming Xue22, Li Yan23, Jing Yang24, Lihui Yang25, Yongli Yao26, Zhen Ye27, Qiao Zhang28, Lihui Zhang29, Jun Zhu30, Mei Zhu31, Zhongyan Shan1, Weiping Teng1. 1. Department of Endocrinology and Metabolism, The Institute of Endocrinology, The First Hospital of China Medical University, Shenyang, P.R. China. 2. Department of Endocrinology, Chinese PLA General Hospital, Beijing, P.R. China. 3. Department of Endocrinology, Southwest Hospital, Third Military Medical University, Chongqing, P.R. China. 4. Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, Dalian, P.R. China. 5. Department of Endocrinology, Cardiovascular and Cerebrovascular Disease Hospital of Ningxia Medical University, Yinchuan, P.R. China. 6. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Nanchang University, Nanchang, P.R. China. 7. Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China. 8. Department of Endocrinology, Hohhot First Hospital, Hohhot, P.R. China. 9. Department of Endocrinology and Metabolism, The Second Xiangya Hospital, Central South University, Changsha, P.R. China. 10. Research Center of Endocrine and Metabolic Diseases, Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, P.R. China. 11. Department of Endocrinology and Metabolism, Fujian Institute of Endocrinology, Fujian Medical University Union Hospital, Fuzhou, P.R. China. 12. Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital, Zhengzhou University, Zhengzhou, P.R. China. 13. Department of Endocrine, First Affiliated Hospital of Guangxi Medical University, Nanning, P.R. China. 14. Department of Endocrinology, Hainan General Hospital, Haikou, P.R. China. 15. Department of Endocrinology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, P.R. China. 16. Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, P.R. China. 17. Department of Endocrinology, The First Hospital of Lanzhou University, Lanzhou, P.R. China. 18. Department of Endocrinology and Metabolism, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, P.R. China. 19. Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, P.R. China. 20. Department of Endocrinology, Shanghai University of Medicine & Health Sciences-Affiliated Zhoupu Hospital, Shanghai, P.R. China. 21. Department of Endocrinology, The First Hospital of An Hui Medical University, Hefei, P.R. China. 22. Department of Endocrinology, The First People's Hospital of Yunnan Province, Kunming, P.R. China. 23. Department of Endocrinology and Metabolism, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, P.R. China. 24. Department of Endocrinology, The First Hospital of Shanxi Medical University, Taiyuan, P.R. China. 25. Department of Endocrinology and Metabolism, People's Hospital of Tibet Autonomous Region, Lhasa, P.R. China. 26. Department of Endocrinology, Qinghai Provincial People's Hospital, Xining, P.R. China. 27. Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, P.R. China. 28. Department of Endocrinology and Metabolism, Affiliated Hospital of Guiyang Medical University, Guiyang, P.R. China. 29. Department of Endocrinology, Second Hospital of Hebei Medical University, Shijiazhuang, P.R. China. 30. Department of Endocrinology, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, P.R. China. 31. Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, P.R. China.
Abstract
Background: Iodine intake is associated with thyroid autoimmunity. In this study, we evaluated the changes in thyroid autoimmunity after 20 years of universal salt iodization (USI) in China. Methods: A total of 78,470 subjects (18 years or older) from 31 provincial regions of mainland China participated in the study. Serum thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), TSH receptor antibody, thyrotropin (TSH), and urinary iodine concentration (UIC) were measured. Results: Positive TPOAb and TgAb were detected in 10.19% [CI 9.80-10.59] and 9.70% [CI 9.28-10.13] of the subjects, respectively. The prevalence of positive isolated TPOAb (i-TPOAb), positive isolated TgAb (i-TgAb), and double positive TPOAb and TgAb (d-Ab) was 4.52%, 4.16%, and 5.94%, respectively. The prevalence of thyroid antibody positivity was the highest in the iodine-deficient (UIC <100 μg/L) groups. The prevalence of i-TPOAb was inversely associated with more than adequate iodine intake (MAI) and excessive iodine intake (EI); the odds ratio (OR) was 0.89 [CI 0.81-0.98] for MAI and 0.90 [CI 0.81-0.99] for EI. We observed that i-TgAb, like i-TPOAb, was a high-risk factor for subnormal TSH levels (OR = 3.64 [CI 2.62-5.05]) and elevated TSH levels (OR = 1.62 [CI 1.49-1.77]). The prevalence of thyroid antibody positivity varied among five ethnic groups. Conclusions: After two decades of USI, the prevalence of thyroid antibody positivity has remained low. MAI and EI had an inverse relationship with TPOAb positivity, which reveals that UIC between 100 and 299 μg/L is optimal and safe for thyroid autoimmunity. These conclusions need to be confirmed in a follow-up study because this study was a cross-sectional study.
Background: Iodine intake is associated with thyroid autoimmunity. In this study, we evaluated the changes in thyroid autoimmunity after 20 years of universal salt iodization (USI) in China. Methods: A total of 78,470 subjects (18 years or older) from 31 provincial regions of mainland China participated in the study. Serum thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb), TSH receptor antibody, thyrotropin (TSH), and urinary iodine concentration (UIC) were measured. Results: Positive TPOAb and TgAb were detected in 10.19% [CI 9.80-10.59] and 9.70% [CI 9.28-10.13] of the subjects, respectively. The prevalence of positive isolated TPOAb (i-TPOAb), positive isolated TgAb (i-TgAb), and double positive TPOAb and TgAb (d-Ab) was 4.52%, 4.16%, and 5.94%, respectively. The prevalence of thyroid antibody positivity was the highest in the iodine-deficient (UIC <100 μg/L) groups. The prevalence of i-TPOAb was inversely associated with more than adequate iodine intake (MAI) and excessive iodine intake (EI); the odds ratio (OR) was 0.89 [CI 0.81-0.98] for MAI and 0.90 [CI 0.81-0.99] for EI. We observed that i-TgAb, like i-TPOAb, was a high-risk factor for subnormal TSH levels (OR = 3.64 [CI 2.62-5.05]) and elevated TSH levels (OR = 1.62 [CI 1.49-1.77]). The prevalence of thyroid antibody positivity varied among five ethnic groups. Conclusions: After two decades of USI, the prevalence of thyroid antibody positivity has remained low. MAI and EI had an inverse relationship with TPOAb positivity, which reveals that UIC between 100 and 299 μg/L is optimal and safe for thyroid autoimmunity. These conclusions need to be confirmed in a follow-up study because this study was a cross-sectional study.
Entities:
Keywords:
China; iodine; prevalence; thyroid antibody; universal salt iodization