Lower Serum Testosterone Associated with Elevated Polychlorinated Biphenyl Concentrations in Native American Men

Abstract

BackgroundPolychlorinated biphenyls (PCBs) and chlorinated pesticides are endocrine disruptors, altering both thyroid and estrogen hormonal systems. Less is known of action on androgenic systems.ObjectiveWe studied the relationship between serum concentrations of testosterone in relation to levels of PCBs and three chlorinated pesticides in an adult Native American (Mohawk) population.MethodsWe collected fasting serum samples from 703 adult Mohawks (257 men and 436 women) and analyzed samples for 101 PCB congeners, hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (DDE), and mirex, as well as testosterone, cholesterol, and triglycerides. The associations between testosterone and tertiles of serum organochlorine levels (both wet weight and lipid adjusted) were assessed using a logistic regression model while controlling for age, body mass index (BMI), and other analytes, with the lowest tertile being considered the referent. Males and females were considered separately.ResultsTestosterone concentrations in males were inversely correlated with total PCB concentration, whether using wet-weight or lipid-adjusted values. The odds ratio (OR) of having a testosterone concentration above the median was 0.17 [95% confidence interval (CI), 0.05–0.69] for total wet-weight PCBs (highest vs. lowest tertile) after adjustment for age, BMI, total serum lipids, and three pesticides. The OR for lipid-adjusted total PCB concentration was 0.23 (95% CI, 0.06–0.78) after adjustment for other analytes. Testosterone levels were significantly and inversely related to concentrations of PCBs 74, 99, 153, and 206, but not PCBs 52, 105, 118, 138, 170, 180, 201, or 203. Testosterone concentrations in females are much lower than in males, and not significantly related to serum PCBs. HCB, DDE, and mirex were not associated with testosterone concentration in either men or women.ConclusionsElevation in serum PCB levels is associated with a lower concentration of serum testosterone in Native American men.

Obesity and age affect male fertility potential

“…The inhibin-B concentration decreased significantly in men classified as obese compared with those with normal BMIs, confirming results by Globerman et al (23), who studied men with severe obesity (BMI > 40 kg/m 2 ), and Winters et al (24), who reported on 72 healthy men aged 18-24 years. The serum concentration of total T was significantly lower in obese men compared with men with normal BMIs, consistent with previous results (8,25). However, in linear or multiple regressions, BMIs were not correlated with T or FSH.…”

Associations of lead and cadmium with sex hormones in adult males

“…For example, we did not control for polychlorinated biphenyls (PCBs) or phthalate exposures, which have both been identified to be inversely associated with testosterone in males (Goncharov et al, 2009;Meeker and Ferguson, 2014;Specht et al, 2014). These associations tend to be opposite in direction to the positive association between lead and testosterone this analysis identified.…”

Exposure to and health effects of volatile PCBs

“…PCBs also alter sex hormone function, with many congeners and hydroxylated metabolites having estrogenic activity (59). Elevated PCB exposure results in earlier puberty in girls (60) and a reduction in testosterone levels in men and boys (61,62). PCBs suppress the immune system, leading to increased respiratory infections in children (63,64) and elevations in cases of asthma (64,65).…”