Yongze Li1, Di Teng1, Jianming Ba2, Bing Chen3, Jianling Du4, Lanjie He5, Xiaoyang Lai6, Xiaochun Teng1, Xiaoguang Shi1, 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, Guang Ning32, Yiming Mu2, Jiajun Zhao33, 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 and Health Science Affiliated Zhoupu Hospital, Shanghai, P.R. China. 21. Department of Endocrinology, The First Hospital of Anhui 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. 32. Department of Endocrinology and Metabolism, The Institute of Endocrinology, Rui-Jin Hospital Affiliated with Shanghai Jiao-Tong University School of Medicine, Shanghai, P.R. China. 33. Department of Endocrinology, Shandong Provincial Hospital affiliated with Shandong University, Ji'nan, P.R. China.
Abstract
Background: Mandatory universal salt iodization (USI) has been implemented in China for 20 years. Although iodine deficiency disorders are effectively controlled, the risk of excess iodine have been debated. Methods: A nationally representative cross-sectional study with 78,470 enrolled participants, aged 18 years or older, from all 31 provincial regions of mainland China was performed. The participants were given a questionnaire and underwent B-mode ultrasonography of the thyroid. Serum concentrations of thyroid hormones, thyroid antibodies, and urine iodine concentration (UIC) were measured. Results: The median UIC of the adult population was 177.89 μg/L. The weighted prevalence of thyroid disorders in adults were as follows: 0.78% of overt hyperthyroidism, 0.44% of subclinical hyperthyroidism, 0.53% of Graves' disease, 1.02% of overt hypothyroidism, 12.93% of subclinical hypothyroidism, 14.19% of positive thyroid antibodies, 10.19% of positive thyroid peroxidase antibodies, 9.70% of positive thyroglobulin antibodies, 1.17% of goiter, and 20.43% of thyroid nodules. Iodine excess was only associated with higher odds of overt hyperthyroidism and subclinical hypothyroidism, while iodine deficiency was significantly associated with higher odds of most thyroid disorders. In addition, increased iodine intake was significantly associated with elevated serum thyrotropin levels but was inversely associated with thyroid antibodies and thyroid nodules. Conclusions: The long-term mandatory USI program with timely adjustments is successful in preventing iodine deficiency disorders, and it appears to be safe. The benefits outweigh the risks in a population with a stable median iodine intake level of up to 300 μg/L.
Background: Mandatory universal salt iodization (USI) has been implemented in China for 20 years. Although iodine deficiency disorders are effectively controlled, the risk of excess iodine have been debated. Methods: A nationally representative cross-sectional study with 78,470 enrolled participants, aged 18 years or older, from all 31 provincial regions of mainland China was performed. The participants were given a questionnaire and underwent B-mode ultrasonography of the thyroid. Serum concentrations of thyroid hormones, thyroid antibodies, and urine iodine concentration (UIC) were measured. Results: The median UIC of the adult population was 177.89 μg/L. The weighted prevalence of thyroid disorders in adults were as follows: 0.78% of overt hyperthyroidism, 0.44% of subclinical hyperthyroidism, 0.53% of Graves' disease, 1.02% of overt hypothyroidism, 12.93% of subclinical hypothyroidism, 14.19% of positive thyroid antibodies, 10.19% of positive thyroid peroxidase antibodies, 9.70% of positive thyroglobulin antibodies, 1.17% of goiter, and 20.43% of thyroid nodules. Iodine excess was only associated with higher odds of overt hyperthyroidism and subclinical hypothyroidism, while iodine deficiency was significantly associated with higher odds of most thyroid disorders. In addition, increased iodine intake was significantly associated with elevated serum thyrotropin levels but was inversely associated with thyroid antibodies and thyroid nodules. Conclusions: The long-term mandatory USI program with timely adjustments is successful in preventing iodine deficiency disorders, and it appears to be safe. The benefits outweigh the risks in a population with a stable median iodine intake level of up to 300 μg/L.
Entities:
Keywords:
China; iodine; prevalence; thyroid disorders; universal salt iodization