February 05, 2016
Study: “Environmental Research” publishes Emory University study offering evidence that PFOA exposure is not associated with early menopause, refuting earlier studies
Perfluorooctanoic acid (PFOA), a suspected endocrine disruptor, is a bio-persistent chemical found at low levels in the serum of nearly all U.S. residents. Early menopause has been positively associated with serum PFOA in prior cross-sectional studies.
We conducted a longitudinal analysis of age at menopause among women, aged ≥40 years, (N=8759) in a Mid-Ohio Valley community cohort, exposed to high PFOA levels via contaminated drinking water. Using estimated retrospective year-specific serum PFOA concentrations (1951–2011), we examined the associations between PFOA, as cumulative exposure or year-specific serum estimates, and natural menopause using a Cox proportional hazards models. As participants were initially recruited in 2005–2006, we also analyzed the cohort prospectively (i.e., from the time of enrollment), using both modeled cumulative PFOA, and PFOA serum levels measured in 2005-2006. Women with hysterectomy (a competing risk) were either censored or excluded from the analysis.
Neither in the retrospective nor the prospective cohort did we find a significant (at α=0.05) trend between PFOA exposure and natural menopause. The non-significant, hazard ratios by quintile of increasing cumulative serum PFOA were 1.00 (referent), 1.00, 1.09, 1.05 and 1.06 (trend test for log cumulative exposure: p=0.37) with hysterectomies censored, and 1.00 (referent), 1.06, 1.13, 1.09 and 1.11 (trend test for log cumulative exposure: p=0.85) with hysterectomies excluded. Year-specific serum estimates were also not associated with early menopause.
Our data suggest that earlier age at menopause is not associated with PFOA exposure.