Associations between iodine intake, thyroid volume, and goiter rate in school-aged Chinese children from areas with high iodine drinking water concentrations
| Autor: | Jun Shen, Wen Chen, Elizabeth N. Pearce, Michael B. Zimmermann, Wanqi Zhang, Xiang Li, Alicia L. Carriquiry, Yalan Wu, Long Tan, Wei Wang, Wen Jiang, Jianchao Bian, Xiaoming Wang |
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| Rok vydání: | 2017 |
| Předmět: |
Male
0301 basic medicine China medicine.medical_specialty Goiter Thyroid Gland Medicine (miscellaneous) chemistry.chemical_element 030209 endocrinology & metabolism Excessive iodine intake Urine Iodine Excretion 03 medical and health sciences 0302 clinical medicine Animal science Reference Values Internal medicine Prevalence medicine Humans Child High iodine Iodine intake 030109 nutrition & dietetics Nutrition and Dietetics Drinking Water Thyroid medicine.disease Trace Elements Cross-Sectional Studies Endocrinology medicine.anatomical_structure chemistry Female |
| Zdroj: | The American Journal of Clinical Nutrition. 105:228-233 |
| ISSN: | 0002-9165 |
| DOI: | 10.3945/ajcn.116.139725 |
| Popis: | BACKGROUND Excessive iodine intake may have adverse effects on the thyroid, particularly in children, but the safe upper iodine intake concentration in children is unclear. OBJECTIVE We assessed the adverse effects of high iodine intake from iodine-rich drinking water on thyroid size in children by examining associations between thyroid volume (Tvol), total goiter rate (TGR), and iodine intake. DESIGN In a multistage cross-sectional survey, we collected two 24-h urine samples on 2 nonconsecutive days and determined 24-h urinary iodine excretion, then calculated habitual daily iodine intake. Ultrasonographic Tvol was measured, and TGR was calculated based on international and Chinese reference ranges for Tvol in children. RESULTS This study included 2089 children from Shandong province, where the median (IQR) drinking water iodine concentration was 183 μg/L (69-406 μg/L). The median (IQR) 24-h urinary iodine concentrations for the 2 collections were 381 μg/L (203-649 μg/L) and 398 μg/L (202-687 μg/L), respectively. The median (IQR) habitual daily iodine intake of children was 298 μg/d (186-437 μg/d). Tvols were slightly higher in boys than in girls (P = 0.035). The overall TGR was 9.7% and did not differ by sex. The TGR was ∼5% for children aged 7-10 and 11-14 y at iodine intakes of 200-249 and 250-299 μg/d, respectively. With the use of logistic regression and 2-step linear regression, a nonlinear association was observed between Tvol, TGR, and iodine intake, with a threshold intake of 150 μg/d. CONCLUSIONS Tvol begins to increase in children when iodine intake is ≥150 μg/d, and the TGR exceeds 5% when daily iodine intake is ≥250 μg/d for children aged 7-10 y and ≥300 μg/d for children aged 11-14 y. Our findings suggest that 150-249 and 150-299 μg/d seem to be safe upper iodine intake ranges for children aged 7-10 and 11-14 y, respectively. This trial was registered at clinicaltrials.gov as NCT02915536. |
| Databáze: | OpenAIRE |
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