Author:

Keywords:

Adult, Animals, Belgium, Biomarkers, Cell Line, Tumor, Diet, Dioxins, Environmental Pollutants, Estradiol, Follicle Stimulating Hormone, Humans, Inhibins, Luteinizing Hormone, Male, Rats, Receptors, Aryl Hydrocarbon, Sex Hormone-Binding Globulin, Sperm Count, Testosterone, Science & Technology, Life Sciences & Biomedicine, Environmental Sciences, Public, Environmental & Occupational Health, Toxicology, Environmental Sciences & Ecology, dioxin, DR-CALUX, egg consumption, hormones, male fertility, semen volume, sperm concentration, TCDD, testosterone, POLYCHLORINATED AROMATIC-HYDROCARBONS, SEMINAL-VESICLE, SEMEN QUALITY, PERSISTENT ORGANOCHLORINES, INFERTILE MEN, MALE-RATS, EXPOSURE, 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN, BIPHENYLS, HUMANS, Flemish Environment and Health Study Group, 05 Environmental Sciences, 11 Medical and Health Sciences, 32 Biomedical and clinical sciences, 41 Environmental sciences, 42 Health sciences

Abstract:

BACKGROUND: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and some related environmental contaminants are aryl hydrocarbon receptor (AhR) ligands that exert reproductive and developmental toxicity in laboratory animals. In humans, fertility-related effects are less documented. OBJECTIVE: The aim of this study was to investigate the relationship between dioxin-like biological activity in serum and parameters of reproductive status in men from the general population 5 months after a polychlorinated biphenyl and dioxin food-contamination episode in Belgium. DESIGN: In the framework of the cross-sectional Flemish Environment and Health Study (FLEHS), we recruited 101 men 20-40 years of age and evaluated sperm parameters, measured sex hormones, and gathered information on a number of lifestyle factors. In addition, we determined the AhR-mediated enzymatic response elicited by individual serum samples and expressed it as TCDD equivalent concentrations (CALUX-TEQs) using an established transactivation assay. RESULTS: Age (p = 0.04) and the frequency of fish (p = 0.02) and egg (p = 0.001) consumption were independent positive determinants of serum dioxin-like activity. After correcting for possible confounders, we found that a 2-fold increase in CALUX-TEQ > 16 pg/L was associated with a 7.1% and 6.8% (both p = 0.04) decrease in total and free testosterone, respectively. We also observed a more pronounced drop in semen volume of 16.0% (p = 0.03), whereas sperm concentration rose by 25.2% (p = 0.07). No relationship was found with total sperm count or sperm morphology. CONCLUSIONS: These data suggest an interaction of dioxin-like compounds with the secretory function of the seminal vesicles or prostate, possibly indirectly through an effect on testosterone secretion, at levels not affecting spermatogenesis as such.