ABSTRACT
BACKGROUND: Many endocrine disrupting chemicals (EDCs), for instance phthalates and benzophenones, are associated with adverse fertility outcomes and semen quality parameters. OBJECTIVE: To evaluate if concentrations of selected phthalate metabolites and benzophenones measured in follicular fluid are associated with fertility outcomes (i.e., reproductive hormones, antral follicle count, detected heartbeat at gestational week 7, and live birth) and, in a supplementary study, if measured concentrations of chemicals in follicular fluid can exert biological effects on human spermatozoa. METHODS: Overall, 111 couples from a fertility clinic in Denmark contributed with 155 follicular fluid samples. Concentrations of 43 metabolites from 19 phthalates and phthalate substitutes and six benzophenones were measured in follicular fluid using liquid chromatography-tandem mass spectrometry. Multiple linear and logistic regression with an applied generalized estimating equation model allowing more than one measurement per woman assessed the association between follicular EDC levels and fertility outcomes. The assessment of biological effects of individual and mixtures of EDCs on human spermatozoa was conducted through a human sperm cell based Ca2+-fluorimetric assay. RESULTS: Benzophenone-3 (BP-3) and seven metabolites of five phthalates were detectable in follicular fluid. Women with metabolites of dibutyl phthalate isomers in the highest tertiles had lower antral follicle count (MiBP: ß = -5.35 [95 % CI: -9.06; -2.00], MnBP: ß = -5.25 [95 % CI: -9.00; -2.00]) and lower odds for detecting a heartbeat at gestational week 7 (MiBP: OR = 0.35 [95 % CI: 0.14; 0.91], MnBP: OR = 0.39 [95 % CI: 0.13; 1.15]). Mixtures of the measured concentrations of BP-3 and the seven phthalate metabolites induced a small significant increase in the intracellular calcium ion concentration in human spermatozoa from healthy donors (n = 3). DISCUSSION: Phthalate metabolites and BP-3 were detectable in follicular fluid and high concentrations of some phthalate metabolites were linked with lower chance of successful fertility treatment outcomes. Chemical mixture concentrations in follicular fluid induced a calcium response in human spermatozoa highlighting possible biological effects at physiologically relevant concentrations.
Subject(s)
Endocrine Disruptors , Environmental Pollutants , Phthalic Acids , Humans , Male , Female , Follicular Fluid/metabolism , Semen Analysis , Calcium , Semen/metabolism , Phthalic Acids/metabolism , Endocrine Disruptors/metabolism , Benzophenones/metabolism , Environmental Pollutants/metabolismABSTRACT
Previous studies have suggested that variants in the protocadherin-1 (PCDH1) gene, which is important for cell-cell adhesion, are associated with asthma, bronchial, hyperresponsiveness and atopic dermatitis in school children. Our aim was to associate common variants of the PCDH1 gene with longitudinally assessed asthma phenotypes and atopic dermatitis in early childhood. We analysed eight single-nucleotide polymorphisms in PCDH1 from 411 children born to asthmatic mothers from the Copenhagen Prospective Studies on Asthma in Childhood birth cohort. Asthma and atopic dermatitis were diagnosed prospectively to the age of 7 years and asthma was categorised by temporal pattern: transient early respiratory symptoms, persistent symptoms and late-onset symptoms. Bronchial responsiveness was measured at age 6 years. We used additive genetic models. Kaplan-Meier plots revealed early onset in hetero- and homozygotes for the rs10063472-T allele. Significant association was observed between the transient early phenotype and rs10063472-T (transient early versus all: OR 1.91, 95% CI 1.21-3.01, p=0.0058; transient early versus asymptomatic: OR 2.00, 95% CI 1.23-3.25, p=0.0053). No association was observed for other symptom patterns or bronchial responsiveness. Significant association was observed for atopic dermatitis and rs11167761-A (OR 1.85, 95% CI 1.24-2.75, p=0.0026). Common variations in PCDH1 increase the risk of developing both transient early asthma and atopic dermatitis in early childhood.