Interacting effects of selected trace and toxic metals on thyroid function

Abstract

Interacting effects of blood levels of manganese (Mn), selenium, cadmium (Cd), lead (Pb), and mercury, and serum levels of iron (Fe), zinc (Zn), and copper (Cu) on thyroid function in general US population were evaluated. Data from the National Health and Nutrition Examination Survey for 2011–2012 were used for this evaluation. The variables used to evaluate thyroid function were as follows: thyroid-stimulating hormone, free and total triiodothyronine (FT3, TT3), free and total thyroxine (FT4, TT4), and thyroglobulin (Tg). Levels of FT4 were positively associated with the levels of copper and negatively associated with the levels of Fe for males only. Elevated levels of Mn and Fe were associated with increased levels of FT3 for both males and females. TT4 had a positive association with the levels of Cu and a negative association with the levels of Fe for both males and females.

Keywords:

• manganese
• iron
• copper
• zinc
• cadmium
• lead
• mercury
• selenium
• thyroid

Acknowledgement

The views expressed herein are those of the author(s) and do not reflect the official policy of the Department of the Army, Department of Defense, the US Government or Empiristat, Inc.

Disclosure statement

The authors declares that except RBJ being a contractor and YSC being an employee of Womack Army Medical Center, they have no financial and other conflicts that could have affected the conclusions arrived at in this paper.

Additional information

Funding

No funds were provided to the author to conduct this research. All data used in this research are available free of charge from www.cdc.gov/nchs/nhanes.htm.