The Effects of PCB Exposure and Fish Consumption on Endogenous Hormones. (Articles)
Persky, Victoria, Turyk, Mary, Anderson, Henry A., Hanrahan, Lawrence P., Falk, Claire, Steenport, Dyan N., Chatterton, Robert, Jr., Freels, Sally, Environmental Health Perspectives
Previous studies have suggested that exposure to polychlorinated biphenyls (PCBs) may alter thyroid function, but data on effects of PCB exposure on other endogenous hormones has been lacking. The current study is ancillary to a larger investigation of the effects of Great Lakes fish consumption on PCBs and reproductive function. In the current study we examine associations of PCBs, 1,1-bis (4-chlorophenyl)-2,2-dichloroethene (DDE), and fish consumption with thyroid and steroid hormones in 178 men and PCBs, DDE, and fish consumption with thyroid hormones in 51 women from the original study. Serum PCB level and consumption of Great Lakes fish are associated with significantly lower levels of thyroxine ([T.sub.4]) and free thyroxine index (FTI) in women and with significantly lower levels of [T.sub.4] in men. Fish consumption, but not PCB level, is significantly and inversely associated with triiodothyronine ([T.sub.3]) in men. Results for thyroid-stimulating hormone (TSH) are inconsistent. Among men, there are significant inverse associations of both PCB and fish consumption with sex hormone-binding globulin (SHBG)-bound testosterone, but no association with SHBG or free testosterone. There are no significant overall associations of PCB, DDE, or fish consumption with estrone sulfate, follicle-stimulating hormone, luteinizing hormone, or dehydroepiandrosterone sulfate. The results of this study are consistent with previous studies showing effects of fish consumption and PCB exposure on thyroid hormones and suggest that PCBs may also decrease steroid binding to SHBG. Elucidation of specific mechanisms must await future investigations. Key words: consumption, fish, hormones, PCBs, steroid, thyroid. Environ Health Perspect 109:1275-1283 (2001). [Online 30 November 2001]
There is an increasing body of animal data suggesting that high levels of polychlorinated biphenyl (PCB) exposure may be associated with a wide variety of health effects, including changes in hormonal balance. Of particular interest are effects on thyroid hormones. The concern over in utero effects of low-level PCB exposure relates to known neurotoxic effects of hypothyroidism on developing organisms (1), with potential effects being delayed neurodevelopment, decreased intelligence, and hearing deficits. Human studies of low-level exposures, however, are sparse. Alterations in thyroid hormones have been seen after exposure to PCBs and polychlorinated dibenzofurans after a mass contamination in Yusho, Japan (2), in children living near an industrial waste incinerator in Germany (3), and in some (4,5) but not all studies (6) of children exposed to low levels of PCBs in utero. Studies of PCB effects on other hormones have been notably lacking.
A consortium that was formed to assess exposure risks of contaminated Great Lakes fish consumption (7,8) offered a unique opportunity to examine the effects of low-level PCB exposure and fish consumption on endogenous hormone levels. This consortium is an outgrowth of The Great Lakes Water Quality Agreement of 1978 in which the health departments of Wisconsin, Illinois, Indiana, Ohio, and Michigan formed the consortium to assess health risks of exposure to contaminated Great Lakes fish (9). Previous investigations of this cohort have shown that PCB and DDE levels were significantly correlated with age, body mass index, male versus female sex, and frequency of sport fish and Great Lakes sport fish consumption (10,11). In this report we summarize the associations of thyroid hormones with PCB and DDE levels in males and females, and the associations of steroid hormones with PCB and DDE levels in males in a subset of the original cohort.
Prior to initiation of this study protocol, it was reviewed and approved by the University of Wisconsin-Madison Medical School Human Subjects Committee and University of Illinois-Chicago Human Subjects Review Boards. …