Adolescents aged 12 to 21 years are two to three times more sensitive than the general population to common environmental contaminants that can disrupt thyroid function and therefore should have the latter checked, according to US researchers.
The thyroid-blocking effects of exposure to three common environmental contaminants — perchlorate, thiocyanate, and nitrate — also appear to be different in boys and girls, say Jenica McMullen, New York University School of Medicine, New York, and colleagues in their report published online April 20 in the Journal of Clinical Endocrinology and Metabolism.
Perchlorate, thiocyanate, and nitrate all inhibit the function of sodium-iodide symporter (NIS) in thyroid follicular cells at levels currently found in the environment, they point out. NIS function is key to thyroid-hormone synthesis, and disruption is a leading cause of hypothyroidism.
In adolescents, disruptions of normal thyroid function can profoundly affect every organ system, including cognitive and cardiac function, bone strength, and metabolism. Clinically, this can present as declining growth rates and changes in academic performance, including poor attention, the researchers say.