Effect of the phthalates exposure on sex steroid hormones in the US population.
Level 4 - case-series / case-control
Cross-sectional analysis of survey data
PubMed 35051761 · doi:10.1016/j.ecoenv.2022.113203
What was done
Using data from the National Health and Nutrition Examination Survey (NHANES) 2015–2016, researchers analyzed 1,768 U.S. adults to evaluate associations between 16 urinary phthalate metabolites (including legacy phthalates and newer replacement compounds) and three serum sex hormones (testosterone, estradiol, and sex hormone-binding globulin). Adjusted multiple linear regression and logistic regression models were used to estimate gender-specific associations.
What was found
Most urinary phthalate metabolite concentrations were below 50 ng/mL. In the overall sample, phthalate exposure was associated with decreased testosterone and increased estradiol and SHBG. In males, testosterone levels were inversely associated with MnBP (β: -0.05, 95% CI: -0.09, 0), MEOHP (β: -0.05, 95% CI: -0.09, -0.01), MEHHP (β: -0.04, 95% CI: -0.08, 0), MECPP (β: -0.07, 95% CI: -0.11, -0.03), MEP (β: -0.03, 95% CI: -0.06, 0), and MiBP (β: -0.05, 95% CI: -0.10, -0.01). In females, ln-transformed estradiol increased by 0.18 pg/mL (95% CI: 0.05, 0.31) per 1 ln-unit increase in MEHP and by 0.15 pg/mL (95% CI: 0.01, 0.29) per 1 ln-unit increase in MNP.
Why it matters
This study provides population-level evidence that exposure to both legacy phthalates and newer replacement alternatives is correlated with altered sex steroid hormone levels in adults, indicating that replacement compounds warrant continued endocrine-disruption screening.
Limits
The cross-sectional design prevents causal or temporal inferences. Phthalates and hormones were measured from single-spot biospecimens, which may not capture temporal variability or pulsatile hormone secretion. Residual confounding from unmeasured environmental co-exposures or diet remains possible.
Cited by
- supports Higher levels of phthalates correlate with decreased testosterone levels in males.