Investigation on the relationship between the urinary fluoride level and structure and function of thyroid in school-age children / 公共卫生与预防医学

ABSTRACT

Objective To explore the relationship between fluoride exposure levels and thyroid structure and function in school-age children, and to provide epidemiological evidence for the prevention and treatment of thyroid diseases and for the control of high fluoride hazards. Methods In 2019, 217 children aged 8-10 years were selected from 3 primary schools in the historical high fluoride area of Tianjin. Basic information was collected by questionnaire surveys. Urine and blood samples were collected for the determination of urine iodine, urine fluoride, and thyroid hormone as well as antibodies. The dental fluorosis was examined by Dean’s method and the thyroid structure was examined by ultrasound. Results There was no significant difference in gender, age and BMI of children with different urine fluoride levels (P>0.05). There was significant difference in the degree of dental fluorosis among children with different urine fluoride levels（χ2=16.263, P=0.012）, and the prevalence of dental fluorosis was higher in children with higher urine fluorine level. There was no significant difference in goiter, nodule, hypothyroidism, hypothyroidism and antibody double positive distribution among children with different urine fluoride levels (P>0.05), but the distribution of TGAb+ or TPOAb+ showed significant difference (χ2=8.697，P=0.034). Logistic analysis showed that there was no correlation between urinary fluoride level and antibody single positive (P>0.05). Conclusion Compared with children with low fluoride exposure levels, children with high fluoride exposure have higher antibody single positive rate, but comprehensive analysis do not find a positive correlation between urinary fluoride level and thyroid structure and disease.