Iodine Modifies the Susceptibility of Thyroid to Fluoride Exposure in School-age Children: a Cross-sectional Study in Yellow River Basin, Henan, China
- 21 January 2021
- journal article
- research article
- Published by Springer Science and Business Media LLC in Biological Trace Element Research
- Vol. 199 (10), 1-9
- https://doi.org/10.1007/s12011-020-02519-8
Abstract
Excessive fluoride exposure has detrimental effects on the thyroid gland, which may be modified by iodine. However, the role of iodine in it remains unclear. This study aims to evaluate the role of iodine in thyroid abnormalities caused by fluoride exposure in school-age children. A total of 446 children aged 7–12 years were recruited from Tongxu County, Henan province, in 2017 (ZZUIRB 2017-018). We obtained demographic information through questionnaire surveys. The concentrations of urinary fluoride (UF) and urinary iodine (UI) were determined by the ion-selective electrode method and the catalytic spectrophotometric method, respectively. The radiation immunoassay was used to determine the serum concentrations of total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH). The B-mode ultrasound was performed to assess thyroid volumes (Tvols). The associations between fluoride exposure and thyroid-related indicators were tested by linear regression models. We found that Tvols increased by 0.22 (95% CI: 0.14, 0.31) cm3 with each standard deviation increment of UF. Moreover, Tvols in boys were more susceptible to fluoride exposure than those in girls, and the Tvols of children with high urinary iodine are less susceptible to fluoride exposure (P for interaction < 0.05). We also observed that TT3 levels were negatively related to UF concentrations at moderate urinary iodine levels (≤ 300 μg/l). Fluoride exposure can elevate the Tvols of school-age children, especially in boys, and high levels of iodine may alleviate this effect to some extent.Funding Information
- National Natural Science Foundation of China (81972981, 81673116)
- Science and Technology Department of Henan Province (162300410272)
- Zhengzhou University (2020zzuJXLX003)
This publication has 48 references indexed in Scilit:
- Intake of water and beverages of children and adolescents in 13 countriesEuropean Journal of Nutrition, 2015
- Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking waterJournal of Epidemiology and Community Health, 2015
- Ameliorative Effect of Resveratrol Against Fluoride-Induced Alteration of Thyroid Function in Male Wistar RatsBiological Trace Element Research, 2014
- The effects and underlying mechanism of excessive iodide on excessive fluoride-induced thyroid cytotoxicityEnvironmental Toxicology and Pharmacology, 2014
- Role of nitric oxide and vascular endothelial growth factor in fluoride-induced goitrogenesis in ratsEnvironmental Toxicology and Pharmacology, 2012
- Radiation-induced hypothyroidism in head and neck cancer patients: A systematic reviewRadiotherapy and Oncology, 2011
- Fluoride-induced thyroid dysfunction in rats: roles of dietary protein and calcium levelToxicology and Industrial Health, 2009
- Effect of Iodine Intake on Thyroid Diseases in ChinaThe New England Journal of Medicine, 2006
- Is the fluoride/creatinine ratio of a spot urine sample indicative of 24‐h urinary fluoride?Community Dentistry and Oral Epidemiology, 2006
- Sources of halogens in the environment, influences on human and animal healthEnvironmental Geochemistry and Health, 1988