Goitrogenic anions, thyroid-stimulating hormone, and thyroid hormone in infants.
BACKGROUND
Environmental exposure of infants to perchlorate, thiocyanate, nitrate, might interfere with thyroid function. U.S. women with higher background perchlorate exposure have higher thyroid-stimulating hormone (TSH) and lower thyroxine (T4). There are no studies with individual measures of thyroid function and these goitrogens available in infants.


OBJECTIVE
We examined the association of urinary perchlorate, nitrate, iodide, and thiocyanate with urinary T4 and TSH in infants and whether that association differed by sex or iodide status.


METHODS
We used data and samples from the Study of Estrogen Activity and Development, which assessed hormone levels of full-term infants over the first 12 months of life. The study included 92 full-term infants between birth and 1 year of age seen up to four times. Perchlorate, thiocyanate, nitrate, and iodide were measured in 206 urine samples; TSH and T4 and were measured in urines and in 50 blood samples.


RESULTS
In separate mixed models, adjusting for creatinine, age, sex, and body mass index, infants with higher urinary perchlorate, nitrate or thiocyanate had higher urinary TSH. With all three modeled, children with higher nitrate and thiocyanate had higher TSH, but higher perchlorate was associated with TSH only in children with low iodide. Unexpectedly, exposure to the three chemicals was generally associated with higher T4.


CONCLUSIONS
The association of perchlorate exposure with increased urinary TSH in infants with low urinary iodide is consistent with previous findings. Higher thiocyanate and nitrate exposure were also associated with higher TSH in infants.
Cao
Yang
Y
Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA.
Blount
Benjamin C
BC
Valentin-Blasini
Liza
L
Bernbaum
Judy C
JC
Phillips
Terry M
TM
Rogan
Walter J
WJ
D013956:Antithyroid Agents / Q000652:urine; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007454:Iodides / Q000652:urine; D008297:Male; D009566:Nitrates / Q000633:toxicity / Q000652:urine; D010472:Perchlorates / Q000633:toxicity / Q000652:urine; D013861:Thiocyanates / Q000633:toxicity / Q000652:urine; D013963:Thyroid Hormones / Q000652:urine*; D013972:Thyrotropin / Q000633:toxicity*
D013956:Antithyroid Agents; D007454:Iodides; D009566:Nitrates; D010472:Perchlorates; D013861:Thiocyanates; D013963:Thyroid Hormones; D013972:Thyrotropin; C031760:thiocyanate; C494474:perchlorate