Milken Institute School of Public Health Poster Presentations (Marvin Center & Video)
Phthalate exposure and risk of bacterial vaginosis among U.S. reproductive-aged women, NHANES 2001-2004
Poster Number
39
Document Type
Poster
Status
Staff
Abstract Category
Environmental and Occupational Health
Keywords
Vaginal microbiota, endocrine disruptors, NHANES, women’s health
Publication Date
Spring 2018
Abstract
Introduction: Consumer product chemicals, such as phthalates, that are found in feminine products may affect the vaginal microbiota and the etiology of bacterial vaginosis (BV). Our objective was to estimate the association between phthalate exposure and BV in a cross-sectional, population-based sample of reproductive-aged women.
Methods: We used data on 940 women aged 18-49 in the National Health and Nutrition Examination Survey, 2001-2004. Phthalate metabolites were measured in urine and include mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), and metabolites of di (2-ethylhexyl) phthalate (DEHP). To control for measurement error from urinary diluteness, we used covariate-adjusted standardization with inclusion of urinary creatinine concentration as a covariate. BV was assessed using Nugent’s Gram stain score, categorized as no BV (score 0-3), intermediate (4-6) and Nugent-score BV (7-10). We used survey-weighted multinomial logistic regression to model the Nugent-score categories, adjusting for age, race/ethnicity, BMI, education, and past six-month vaginal douching.
Results: In unadjusted models, MnBP (Q4 RR 3.12, 95% CI 1.79, 5.41, p trend <0.001), and ΣDEHP metabolites (Q4 RR 2.43, 95% CI 1.43, 4.12, p trend=0.04) were associated with BV. The association of MnBP with BV persisted after adjustment for confounders (Q4 RR 2.25, 95% CI 1.24, 4.20, p trend=0.02). However, associations for MnBP and ΣDEHP were attenuated after creatinine adjustment (MnBP Q4 RR 1.11, 95% CI 0.63, 1.96, p trend = 0.55; ΣDEHP Q4 0.72, 95% CI 0.37, 1.39, p trend=0.35).
Conclusion: Elevated urinary concentrations of phthalates were observed among women with Nugent-score BV. Associations were attenuated after creatinine adjustment; however, this adjustment may not be optimal as urinary diluteness may be physiologically related to BV. We recommend further investigation of environmental chemicals and BV using novel methods for direct assessment of intravaginal exposure.
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Phthalate exposure and risk of bacterial vaginosis among U.S. reproductive-aged women, NHANES 2001-2004
Introduction: Consumer product chemicals, such as phthalates, that are found in feminine products may affect the vaginal microbiota and the etiology of bacterial vaginosis (BV). Our objective was to estimate the association between phthalate exposure and BV in a cross-sectional, population-based sample of reproductive-aged women.
Methods: We used data on 940 women aged 18-49 in the National Health and Nutrition Examination Survey, 2001-2004. Phthalate metabolites were measured in urine and include mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), and metabolites of di (2-ethylhexyl) phthalate (DEHP). To control for measurement error from urinary diluteness, we used covariate-adjusted standardization with inclusion of urinary creatinine concentration as a covariate. BV was assessed using Nugent’s Gram stain score, categorized as no BV (score 0-3), intermediate (4-6) and Nugent-score BV (7-10). We used survey-weighted multinomial logistic regression to model the Nugent-score categories, adjusting for age, race/ethnicity, BMI, education, and past six-month vaginal douching.
Results: In unadjusted models, MnBP (Q4 RR 3.12, 95% CI 1.79, 5.41, p trend <0.001), and ΣDEHP metabolites (Q4 RR 2.43, 95% CI 1.43, 4.12, p trend=0.04) were associated with BV. The association of MnBP with BV persisted after adjustment for confounders (Q4 RR 2.25, 95% CI 1.24, 4.20, p trend=0.02). However, associations for MnBP and ΣDEHP were attenuated after creatinine adjustment (MnBP Q4 RR 1.11, 95% CI 0.63, 1.96, p trend = 0.55; ΣDEHP Q4 0.72, 95% CI 0.37, 1.39, p trend=0.35).
Conclusion: Elevated urinary concentrations of phthalates were observed among women with Nugent-score BV. Associations were attenuated after creatinine adjustment; however, this adjustment may not be optimal as urinary diluteness may be physiologically related to BV. We recommend further investigation of environmental chemicals and BV using novel methods for direct assessment of intravaginal exposure.