Mercury and thyroid autoantibodies in U.S. women, NHANES 2007-2008

Associations between positive thyroid autoantibodies and total blood mercury in women were evaluated using the National Health and Nutrition Examination Survey (NHANES), 2007-2008. Women are at increased risk for autoimmune disorders, mercury exposure has been associated with cellular autoimmunity and mercury accumulates in the thyroid gland. We used multiple logistic regression to evaluate the associations between total bloodmercury and thyroglobulin autoantibody antibody positivity and thyroid peroxidase autoantibody positivity in non-pregnant, non-lactating women aged 20 and older not currently using birth control pills or other hormone therapies, adjusted for demographic factors, menopausal status, nutrient intake and urine iodine (n=2047). Relative to women with the lowest mercury levels (≤0.40 μg/L), women with mercury >1.81 μg/L (upper quintile) showed 2.24 (95% CI=1.22, 4.12) greater odds for thyroglobulin autoantibody positivity (p(trend)=0.032); this relationship was not evident for thyroid peroxidase autoantibody positivity. Results suggest an association between mercury and thyroglobulin autoantibody positivity.