Association between arsenic exposure and thyroid function: data from NHANES 2007–2010

The association of arsenic variables in urine, total arsenic (UAS), arsenobetaine (UAB), dimethylarsinic acid (UDMA), and arsenic adjusted for arsenobetaine (UAAS) with thyroid-stimulating hormone (TSH), free and total serum thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin (TGN) was evaluated by analyzing data from 2007-2010 National Health and Nutrition Examination Survey. For iodine deficient males, there was a positive association between TSH and UDMA (p < 0.01) and a negative association between the levels of TT4 and UDMA (p < 0.01). Levels of UAAS were inversely associated with the levels of TT4 for both iodine-deficient (p = 0.054) and iodine-replete females (p < 0.01). For iodine-replete females, levels of both TSH and TGN increased with decrease in the levels of both UAB (p < 0.01) and UAS (p < 0.01). There was also a negative association between TSH and UAB as well as UAS (p < 0.01). For iodine-replete males, increased levels of UDMA were associated with decreasing levels of FT4 (p = 0.03).