Urinary concentrations of phenols, parabens, and triclocarban in relation to uterine leiomyomata incidence and growth

To examine the association of urinary concentrations of phenols, parabens, and triclocarban with incidence and growth of uterine leiomyomata (UL; fibroids). Case-cohort study, nested within the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study. Clinic visits at baseline and every 20 months for 60 months. 754 Black women aged 23–35 years residing in the Detroit, Michigan area (enrolled during 2010–2012). None. At each study visit, women underwent transvaginal ultrasound for measurement of UL incidence and growth and provided urine specimens in which we quantified concentrations of seven phenols, four parabens, and triclocarban. We used Cox proportional hazards regression to estimate hazard ratios and 95% confidence intervals (CIs) characterizing the relation of urinary biomarker concentrations with UL incidence during the 60 months of follow-up. In a subset of UL detected and measured at multiple time points, we used linear regression to assess the associations between biomarker concentrations and UL growth. Urinary biomarker concentrations were generally inversely associated with UL incidence, but the associations were weak and nonmonotonic. For example, hazard ratios comparing concentrations ≥90th with