Daily Bisphenol A Excretion and Associations with Sex Hormone Concentrations: Results from the InCHIANTI Adult Population Study

Abstract

BackgroundBisphenol A (BPA) is a high production volume chemical widely used in packaging for food and beverages. Numerous studies have demonstrated that BPA can alter endocrine function in animals, yet human studies remain limited.ObjectiveWe estimated daily excretion of BPA among adults and examined hypothesized associations with serum estrogen and testosterone concentrations.MethodsWe conducted cross-sectional analyses using data from the InCHIANTI Study, a prospective population-based study of Italian adults. Our study included 715 adults between 20 and 74 years old. BPA concentrations were measured by liquid chromatography–mass spectrometry in 24-hr urine samples. The main outcome measures were serum concentrations of total testosterone and 17β-estradiol.ResultsGeometric mean urinary BPA concentration was 3.59 ng/mL [95% confidence interval (CI), 3.42–3.77 ng/mL], and mean excretion was 5.63 μg/day (5th population percentile, 2.1 μg/day; 95th percentile, 16.4 μg/day). We found higher excretion rates among men, younger respondents, and those with increasing waist circumference (p = 0.013) and weight (p = 0.003). Higher daily BPA excretion was associated with higher total testosterone concentrations in men, in models adjusted for age and study site (p = 0.044), and in models additionally adjusted for smoking, measures of obesity, and urinary creatinine concentrations (β = 0.046; 95% CI, 0.015–0.076; p = 0.004). We found no associations with the other serum measures. We also found no associations with the primary outcomes among women, but we did find an association between BPA and SHBG concentrations in the 60 premenopausal women.ConclusionHigher BPA exposure may be associated with endocrine changes in men. The mechanisms involved in the observed cross-sectional association with total testosterone concentrations need to be clarified.

Bisphenol A exposure and associations with obesity among adults: a critical review

“…For six of the articles, body composition (BMI, WC and/or weight) was the primary outcome of interest (62)(63)(64)67,71,74) . Seven studies included only women (65,67,69,73,74,77,78) , nine of the studies were in general adult populations (62)(63)(64)66,67,70,71,75,76) , one study included men and women ≥60 years (72) and another included only 70-year-old men and women (79) .…”

“…Six studies measured serum BPA levels; four using a competitive ELISA (65,68,73,78) , one using HPLC paired with an electrochemical detector (77) and one using LC and tandem MS (LC-MS/MS) (79) . Ten studies measured total BPA in spot urine samples (62)(63)(64)67,(70)(71)(72)(74)(75)(76) , one study used the geometric mean for two spot samples collected during the same in vitro fertilization cycle (69) and one study measured total BPA in a 24 h urine sample (66) . Urinary BPA levels were measured using GC-MS (63) and/or HPLC and tandem MS (HPLC-MS/MS) (62)(63)(64)66,67,71,72,74) .…”

“…Twelve of the eighteen studies were rated as negative quality (65,(67)(68)(69)(71)(72)(73)(75)(76)(77)(78)(79) , six were neutral quality (62)(63)(64)66,70,74) and none were positive quality. The lack of positive quality studies was typically due to limitations and issues related to BPA exposure measurement (validity question 5), temporality problems (validity question 6) and/or lack of evaluation of confounding factors (validity question 7).…”

“…Urinary BPA levels are much higher and consist largely of conjugated BPA, which can only be formed in vivo, thus acting as a marker for ruling out contamination by extraneous sources (88) . In fourteen of the studies (64,(66)(67)(68)(69)(70)(71)(72)(73)(75)(76)(77)(78)(79) , including five of six studies that measured serum BPA levels, the manuscripts lacked sufficiently detailed information to determine whether BPA-free materials were used to collect, process and store biospecimens. Failure to use BPA-free laboratory materials could lead to sample contamination and inaccurate BPA measurements, particularly with serum measurements (64,65,67,68,73,88) .…”

Parallel assessment of the effects of bisphenol A and several of its analogs on the adult human testis

“…The highest levels of urinary BPA have been associated with elevated estrogen levels in men (Kim et al, 2014;Lassen et al, 2014), as well as with elevated concentrations of serum LH and testosterone (Galloway et al, 2010;Lassen et al, 2014). Urinary BPA levels in BPAexposed workers, compared to non-exposed workers have also been associated with significantly higher risks of male sexual dysfunction (Li et al, 2010), decreased semen quality (Li et al, 2011), and decreased androgen levels (Zhou et al, 2013).…”