Lower serum testosterone associated with elevated polychlorinated biphenyl concentrations in Native American men

Area of Science:

• Environmental Health
• Endocrinology
• Toxicology

Background:

• Polychlorinated biphenyls (PCBs) and chlorinated pesticides are known endocrine disruptors affecting thyroid and estrogenic systems.
• Their impact on androgenic systems, particularly testosterone, is less understood.

Purpose of the Study:

• To investigate the relationship between serum testosterone concentrations and levels of PCBs and specific chlorinated pesticides.
• Focus on an adult Native American (Mohawk) population.

Main Methods:

• Serum samples from 703 adult Mohawks (257 men, 436 women) were analyzed for 101 PCB congeners, HCB, DDE, mirex, testosterone, cholesterol, and triglycerides.
• Logistic regression assessed associations between testosterone and organochlorine levels (wet weight and lipid-adjusted), controlling for age, BMI, and other analytes.
• Analyses were conducted separately for males and females.

Main Results:

• Serum testosterone in males showed an inverse correlation with total PCB concentration (wet-weight and lipid-adjusted).
• Males with the highest tertile of wet-weight PCBs had significantly lower odds of having testosterone above the median (OR=0.17).
• Specific PCBs (74, 99, 153, 206) were inversely related to testosterone; HCB, DDE, and mirex showed no association in either sex. Female testosterone levels were not significantly related to PCBs.

Conclusions:

• Elevated serum PCB levels are associated with reduced serum testosterone concentrations in Native American men.
• PCBs may disrupt the androgenic system in men, warranting further investigation.
• Chlorinated pesticides (HCB, DDE, mirex) did not show a significant association with testosterone in this population.