Association of environmental phenols with endometriosis and uterine leiomyoma: An analysis of NHANES, 2003–2006

Exposure to phenols is widespread since they are found in many everyday products. Given that phenols are considered endocrine disrupting chemicals with the potential to interfere with hormonal activities, they could have adverse effects on female reproductive health. We analyzed cross-sectional data from the National Health and Nutrition Examination Survey (NHANES), 2003–2006 to examine the association between phenols and endometriosis and uterine leiomyoma (fibroids). Levels of bisphenol A (BPA), benzophenone-3, and triclosan were measured using urine samples, and information on endometriosis and fibroids diagnoses as well as other relevant characteristics were ascertained using self-reported questionnaires. Multivariate logistic regression with odds ratios (ORs) and 95 % confidence intervals (CIs) were used to quantify the association between each phenol and female gynecologic condition. Our study included 700 women, of which 53 women had endometriosis and 107 women had fibroids. We found exposure to BPA to be statistically significantly positively associated with endometriosis (p = 0.05); women in the highest exposure quartile had over the three times the odds of having endometriosis relative to women in the lowest quartile (OR=3.58, 95 % CI 1.00–12.89). None of the phenols considered were significantly associated with fibroids. Overall, exposure to BPA increased the odds of having endometriosis, and there appeared to be a dose-response relationship. This suggests that BPA may play a role in the pathogenesis of endometriosis although the cross-sectional nature of NHANES data is a methodological limitation. Additional research on the impact of endocrine disrupting chemicals, like phenols, on female reproductive health should be conducted.