Bisphenol A and phthalates and endometriosis the Endometriosis Natural History Diagnosis and Outcomes Study
Several phthalates but not bisphenol A were associated with incident endometriosis in the population cohort, whereas two phthalates emerged in sensitivity analyses for the operative cohort.
Germaine M. Buck Louis, Ph.D., C. Matthew Peterson, M.D., Zhen Chen, Ph.D., Mary Croughan, Ph.D., Rajeshwari Sundaram, Ph.D., Joseph Stanford, M.D., Michael W. Varner, M.D., Anne Kennedy, M.D., Linda Giudice, M.D., Ph.D., Victor Y. Fujimoto, M.D., Liping Sun, M.S., Lei Wang, Ph.D., Ying Guo, Ph.D., Kurunthachalam Kannan, Ph.D.
Volume 100, Issue 1, Pages 162-169.e2, July 2013
To explore the relation between bisphenol A and 14 phthalate metabolites and endometriosis.
Matched cohort design.
Fourteen clinical centers.
The operative cohort comprised 495 women undergoing laparoscopy/laparotomy, whereas the population cohort comprised 131 women matched on age and residence.
Main Outcome Measure(s):
Surgically visualized or pelvic magnetic resonance imaging diagnosed endometriosis in the two cohorts, respectively.
Odds ratios (OR) and 95% confidence intervals (CIs) were estimated using logistic regression adjusting for age, body mass index, and creatinine. In the population cohort, six phthalate metabolites—mono-n-butyl phthalate, mono-[(2-carboxymethyl) hexyl] phthalate, mono (2-ethyl-5-carboxyphentyl) phthalate, mono (2-ethylhexyl) phthalate, mono (2-ethyl-5-hydroxyhexyl) phthalate, and mono (2-ethyl-5-oxohexyl) phthalate—were significantly associated with an approximately twofold increase in the odds of an endometriosis diagnosis. Two phthalates were associated with endometriosis in the operative cohort when restricting to visualized and histologic endometriosis (monooctyl phthalate; OR 1.38; 95% CI 1.10–1.72) or when restricting comparison women to those with a postoperative diagnosis of a normal pelvis [mono (2-ethylhexyl) phthalate; OR 1.35; 95% CI 1.03–1.78].
Select phthalates were associated with higher odds of an endometriosis diagnosis for women with magnetic resonance imaging–diagnosed endometriosis. The lack of consistency of findings across cohorts underscores the impact of methodology on findings.