title: Safe range of iodine intake levels: a comparative study of thyroid diseases in three women population cohorts with slightly different iodine intake levels.
abstract: Iodine excess may lead to thyroid diseases. Our previous 5-year prospective survey showed that the prevalence and incidence of hypothyroidism or autoimmune thyroiditis increased with iodine intake. The aim of the present study was to investigate the optimal range of iodine intake by comparing the prevalence of thyroid diseases in three areas with slightly different levels of iodine intake. In 2005, 778 unselected women subjects from three areas with different iodine intake levels were enrolled. Levels of serum thyroid hormones, thyroid autoantibodies, and urinary iodine were measured, and thyroid B ultrasounds were performed. Among the subjects with mildly deficient iodine intake, those with adequate intake, and those with more than adequate intake, the prevalence of clinical and subclinical hypothyroidism was 0, 1.13, and 2.84%, respectively (P = 0.014); that of thyroid goiter was 24.88, 5.65, and 11.37%, respectively (P < 0.001); that of serum thyrotropin values was1.01, 1.25, and 1.39 mIU/l, respectively; and that of serum thyrotropin/thyroglobulin ratio was 7.98, 6.84, and 5.11, respectively (P < 0.001). In conclusion, median urinary iodine 100~200 mug/l may reflect the safe range of iodine intake levels. Serum thyrotropin/thyroglobulin ratio might be a better index of evaluating iodine status.
authors.affiliation: Department of Endocrinology and Metabolism, The First Affiliated Hospital, China Medical University, No. 155 Nanjing Bei Street, Heping District, Shenyang, Liaoning Province, 110001, People's Republic of China. tengxiaochun@126.com
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Teng
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Shi
authors.forename: Zhongyan
authors.initials: Z
authors.lastname: Shan
authors.forename: Ying
authors.initials: Y
authors.lastname: Jin
authors.forename: Haixia
authors.initials: H
authors.lastname: Guan
authors.forename: Yushu
authors.initials: Y
authors.lastname: Li
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.forename: Weibo
authors.initials: W
authors.lastname: Wang
authors.forename: Yajie
authors.initials: Y
authors.lastname: Tong
authors.forename: Weiping
authors.initials: W
authors.lastname: Teng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D005461:Fluorine / Q000652:urine; D006042:Goiter / Q000453:epidemiology; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology; D007455:Iodine / Q000008:administration & dosage* / Q000652:urine; D008875:Middle Aged; D015995:Prevalence; D012643:Selenium / Q000097:blood; D013954:Thyroglobulin / Q000097:blood; D013959:Thyroid Diseases / Q000139:chemically induced* / Q000453:epidemiology; D013972:Thyrotropin / Q000097:blood; D015032:Zinc / Q000097:blood
chemical_list: D005461:Fluorine; D013972:Thyrotropin; D013954:Thyroglobulin; D007455:Iodine; D012643:Selenium; D015032:Zinc