Serum Concentration of Thyroid Hormones Long-Term after Sulfur Mustard Exposure.

Background: Despite several reports on the clinical manifestations of sulfur mustard (SM) intoxication, there is no study on serum concentrations of thyroid hormones long-term after SM exposure. In this study, the changes in thyroid functioning parameters 20 yr after SM exposure were evaluated.

Methods: This study is a part of a larger historical cohort study conducted in 2007 following 20 years of the exposure to SM, called Sardasht-Iran cohort study (SICS). We (SICS) comprised an SM-exposed group from Sardasht City, West Azerbaijan Province, Iran (n=169 as hospitalized group and n=203 as non-hospitalized exposed group); and control participants were selected from Rabat, a town near Sardasht (n=126). Peripheral blood samples were taken in fasting state and then the sera were separated. T4, T3, TSH, antithyroglobulin (anti-Tg), and antithyroid peroxidase (anti-TPO) concentrations in the sera were measured by the ELISA method.

Results: The mean of T3 concentration was significantly higher in the exposed than control group (0.88 ± 0.26 nmol/L vs 0.8 ± 0.25 nmol/L, <0.001). The levels of TSH, T4, and T3up were not significantly different between the exposed and control groups. Thyroglobulin level was significantly higher in the exposed non-hospitalized group (56.07 ± 140.22 μg/L vs 17.66 ± 41.49 μg/L, =0.004), but the level of anti-Tg and anti-TPO showed no significant differences between the two groups.

Conclusion: More studies are needed on the alterations in thyroid hormones, their gene expressions, and mechanisms involved in SM exposure to clarify the causes of these alterations.