Urinary phthalate metabolites are associated with decreased serum testosterone in men, women, and children from NHANES 2011-2012.
Level 4 - case-series / case-control
Cross-sectional analysis of survey data (NHANES)
PubMed 25121464 · doi:10.1210/jc.2014-2555
What was done
This cross-sectional study analyzed data from the 2011–2012 US National Health and Nutrition Examination Survey (NHANES) across the general population. Researchers evaluated the relationship between urinary concentrations of 13 phthalate metabolites and serum total testosterone (measured by isotope dilution-liquid chromatography-tandem mass spectrometry), adjusting for confounders and stratifying by sex and age groups (6–12, 12–20, 20–40, 40–60, and 60–80 years).
What was found
Multiple phthalates were associated with significantly lower testosterone levels in both sexes and specific age brackets. In boys aged 6–12 years, an interquartile range increase in di-2-ethylhexyl phthalate (DEHP) metabolites was associated with a 29% reduction in total testosterone (95% CI, 6% to 47%). In adult men, significant or suggestive inverse associations between metabolites of DEHP and dibutyl phthalate and testosterone were observed specifically in the 40–60 age group. In females, the strongest and most consistent inverse associations occurred among women aged 40–60 years. Other age groups lacked detailed numerical estimates in the abstract.
Why it matters
These findings suggest that common environmental exposures to plasticizers are linked to reduced androgen levels in specific demographic groups, including young boys and middle-aged adults.
Limits
The abstract does not state the exact participant sample size. Because the design is cross-sectional, it cannot establish causality or temporal direction. Urinary phthalates and serum testosterone were assessed at a single time point, which may not capture long-term exposure or hormonal fluctuations.
Cited by
- supports A study in men found that those with the highest phthalate levels had 20% lower testosterone compared to men with lower levels.