A meta-analysis of studies investigating the effects of occupational lead exposure on thyroid hormones

Am J Ind Med. 2016 Jul;59(7):583-90. doi: 10.1002/ajim.22591. Epub 2016 Apr 20.

Abstract

Introduction: Investigations of the effects of occupational exposure to lead on the concentrations of thyroid hormones in the blood have not produced consistent results. A meta-analysis was performed to assess the effect of occupational exposure to lead on thyroid hormone concentrations using the results from published studies.

Methods: Group means from studies of the thyroid function of persons occupationally exposed to lead were used in a meta-analysis. Differences between the control and exposed groups, and the slopes between thyroid hormone concentrations and log10 blood lead concentrations or duration of exposure to lead were estimated using mixed models. The hormones analyzed were thyroid stimulating hormone, total and free thyroxine, and total and free triiodothyronine.

Results: No differences in mean thyroid hormone concentrations were found between the exposed and control groups. No relationships were found between blood lead or the duration of exposure to lead and thyroid hormone concentrations.

Conclusion: The results of the analysis do not provide evidence for an effect of occupational lead exposure on thyroid function in men. Am. J. Ind. Med. 59:583-590, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Keywords: blood lead; thyroid stimulating hormone; thyroxine; triiodothryonine.

Publication types

  • Meta-Analysis

MeSH terms

  • Adult
  • Humans
  • Lead / analysis
  • Lead / blood*
  • Occupational Exposure / adverse effects
  • Occupational Exposure / analysis*
  • Thyroid Hormones / blood*

Substances

  • Thyroid Hormones
  • Lead