Predictors and long-term reproducibility of urinary phthalate metabolites in middle-aged men and women living in urban Shanghai

Phthalate and DINCH exposure and ovarian reserve markers among women seeking infertility care

Phthalate exposure can adversely impact ovarian reserve, yet investigation on the influence of its alternative substance, the non-phthalate plasticizer diisononyl-cyclohexane-1,2-dicarboxylate (DINCH), on ovarian reserve is very sparce. We aimed to investigate the associations of phthalate and DINCH exposure as well as their combined mixture with ovarian reserve. This present study included 657 women seeking infertility care in Jiangsu, China (2015-2018). Urine samples during enrollment prior to infertility treatment were analyzed using high-performance liquid chromatography-isotope dilution tandem mass spectrometry (UPLC-MS/MS) to quantify 17 phthalate metabolites and 3 DINCH metabolites. Multivariate linear regression models, Poisson regression models and weighted quantile sum (WQS) regression were performed to access the associations of 17 urinary phthalate metabolites and 3 DINCH metabolites with ovarian reserve markers, including antral follicle count (AFC), anti-Mullerian hormone (AMH), and follicle-stimulating hormone (FSH). We found that the most conventional phthalates metabolites (DMP, DnBP, DiBP, DBP and DEHP) were inversely associated with AFC, and the DINCH metabolites were positively associated with serum FSH levels. The WQS index of phthalate and DINCH mixtures was inversely associated with AFC (% change = -8.56, 95 % CI: -12.63, -4.31) and positively associated with FSH levels (% change =7.71, 95 % CI: 0.21, 15.78). Our findings suggest that exposure to environmental levels of phthalate and DINCH mixtures is inversely associated with ovarian reserve.

Year-to-year variation in phthalate metabolites in the Midlife Women's Health Study

BACKGROUND

Humans are widely exposed to phthalates, which are metabolized in the body and excreted in urine. Phthalate metabolites are excreted within hours of exposure, making urinary phthalate biomarker concentrations highly variable.

OBJECTIVE

The goal of this study was to characterize the long-term variability in phthalate biomarker concentrations in women across the midlife transition and to identify factors that may be associated with increased variability in those phthalate biomarker concentrations by analyzing longitudinal urinary phthalate metabolite data from the Midlife Women's Health Study (2006-2015).

METHODS

A total of 741 women were enrolled in the study for a period of up to 4 years, during which they each provided 2-4 urine samples per year over 4 consecutive weeks that were pooled for analysis (1876 total pools). Nine phthalate metabolites were assessed individually and as molar sums representative of common compounds (all phthalates: ƩPhthalates; DEHP: ƩDEHP), exposure sources (plastics: ƩPlastic; personal care products: ƩPCP), and modes of action (anti-androgenic: ƩAA). Phthalate metabolites were analyzed by quartile using generalized linear models. In addition, the impact of explanatory variables (race, annual family income, and type of work) on phthalate quartile was examined using ordinal logistic regression models.

IMPACT STATEMENT

Phthalate biomarker concentrations are highly variable among midlife women over time, and annual sampling may not be sufficient to fully characterize long-term exposure.

Exposure to bisphenols, parabens and phthalates during pregnancy and postpartum anxiety and depression symptoms: Evidence from women with twin pregnancies

BACKGROUND

Women are vulnerable to suffer from the common mental disorders like anxiety and depression during the postpartum period. Exposure to bisphenols, parabens, and phthalates has been linked to anxiety and depression symptoms in the general population. However, little is known about their impacts on postpartum women.

OBJECTIVE

To evaluate the effects of individual and joint exposure to 11 nonpersistent chemicals during pregnancy on postpartum anxiety and depression.

METHODS

Among 278 mothers from the Wuhan Twin Birth Cohort (WTBC), bisphenols, parabens, and phthalate metabolites were measured in maternal urine samples from each trimester. Self-rating Anxiety Scale (SAS) and Edinburgh Postnatal Depression Scale (EPDS) were administrated at early pregnancy and 1 month and 6 months postpartum to determine anxiety and depression symptoms, respectively. Associations between urinary chemical biomarkers (individual or mixtures) and anxiety and depression symptoms were estimated using multiple informant model and quantile-based g-computation.

RESULTS

With adjustment for confounders, one quartile increase in the overall chemical mixture (bisphenols, parabens and phthalate metabolites) during the second trimester was associated with 1.03-point (95% CI: 0.07, 1.99, P = 0.036) higher EPDS score at 1 month postpartum, in which bisphenol A (BPA) and bisphenol F (BPF) contributed the most to the positive association. Consistent effects were also observed in the multiple informant models. We found that second-trimester BPA and BPF exposure individually showed the strongest and significant associations with anxiety and depression symptoms, and some of associations differed across trimesters (P_{trimester-int} < 0.05).

CONCLUSIONS

Second-trimester nonpersistent chemical exposure was associated with increased postpartum anxiety and depression symptoms.

Phthalates and bone mineral density: a systematic review

BACKGROUND

Exposure to endocrine disruptors, such as phthalates, may impact bone mineral density (BMD) through a variety of mechanisms. Studies of phthalate exposure and BMD in humans are scarce.

OBJECTIVES

To synthesize published data on the association between phthalate metabolites and BMD in humans and to provide methodological suggestions for future research.

METHODS

A single investigator searched PubMed for relevant studies, including observational studies of phthalate exposure and BMD in children and postmenopausal women. Twelve studies were screened with 5 meeting the eligibility criteria and included for review. A quality assessment form was used as a quality measure and key information was extracted from the included studies.

RESULTS

In one prospective study among postmenopausal women, higher levels of monocarboxyoctyl phthalate (MCOP) and monocarboxynonyl phthalate (MCNP) were significantly associated with lower BMD among nonusers of hormone therapy (HT). In cross-sectional studies of postmenopausal women, monoethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono (3-carboxypropyl) phthalate (MCPP), and mono-benzyl phthalate (MBzP) were negatively associated with BMD, and MCNP was positively associated with BMD, but these results were not replicated across studies. In studies of fetal exposure to phthalates and childhood BMD, significant positive associations between MCPP and BMD in children at age 12 years were found in 1 study, while associations were null in the other study.

CONCLUSIONS

Studies among postmenopausal women provide suggestive evidence of an association between urinary phthalate metabolite concentration and decreased BMD. Results from studies of childhood BMD are inconclusive given the limited data and their limitations. More research is needed to address limitations and further investigate the association between phthalate exposure and human BMD.

Combining Urinary Biomarker Data From Studies With Different Measures of Urinary Dilution

BACKGROUND

Guidance is lacking for how to combine urinary biomarker data across studies that use different measures of urinary dilution, that is, creatinine or specific gravity.

METHODS

Among 741 pregnant participants from four sites of The Infant Development and Environment Study (TIDES) cohort, we assessed the relation of maternal urinary di-2-ethylhexyl phthalate (DEHP) concentrations with preterm birth. We compared scenarios in which all sites measured either urinary creatinine or specific gravity, or where measure of dilution differed by site. In addition to a scenario with no dilution adjustment, we applied and compared three dilution-adjustment approaches: a standard regression-based approach for creatinine, a standard approach for specific gravity (Boeniger method), and a more recently developed approach that has been applied to both (covariate-adjusted standardization method). For each scenario and dilution-adjustment method, we estimated the association between a doubling in the molar sum of DEHP (∑DEHP) and odds of preterm birth using logistic regression.

RESULTS

All dilution-adjustment approaches yielded comparable associations (odds ratio [OR]) that were larger in magnitude than when we did not perform dilution adjustment. A doubling of ∑DEHP was associated with 9% greater odds of preterm birth (OR = 1.09, 95% confidence interval [CI] = 0.91, 1.30) when applying no dilution-adjustment method, whereas dilution-adjusted point estimates were higher, and similar across all scenarios and methods: 1.13-1.20 (regression-based), 1.15-1.18 (Boeniger), and 1.14-1.21 (covariate-adjusted standardization).

CONCLUSIONS

In our applied example, we demonstrate that it is possible and straightforward to combine urinary biomarker data across studies when measures of dilution differ.

Association between recurrent breast cancer and phthalate exposure modified by hormone receptors and body mass index

The association between phthalate exposure and breast cancer remains controversial. We performed a prospective patient cohort design to explore the interaction between creatinine-corrected urinary phthalate metabolites and hormone receptors as well as body mass index (BMI) on recurrent breast cancer. In this follow-up study, 636 female breast cancer patients and 45 new recurrent cases diagnosed for a total of 1576.68 person-years of follow-up were recruited. Mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) was negatively associated with breast cancer recurrence, with adjusted hazard ratio (aHR) 3rd vs. 1st quartile of 0.15 (95% CI 0.04–0.51). The MEOHP presented as a non-monotonic dose–response (NMDR) curve, being U-shaped. In the stratification of hormone receptors, MEOHP still exhibited a U-shaped dose–response curve. The third quartile of MEOHP showed significant lowest recurrent risk in the status of ER-positive (aHR 0.18, 95% CI 0.05–0.66), PR-negative (aHR 0.14, 95% CI 0.03–0.63), and HER2-negative (aHR 0.24, 95% CI 0.08–0.76). Whether in BMI < 25 or in BMI ≥ 25, the third quartile of MEOHP was negatively associated with recurrent breast cancer, and there was a negative interaction on an additive scale between MEOHP and BMI (p_interaction = 0.042). The association between MEOHP and recurrent breast cancer was modified by hormone receptors and BMI.

Temporal exposure and consistency of endocrine disrupting chemicals in a longitudinal study of individuals with impaired fasting glucose

Endocrine disrupting chemicals (EDCs) include non-persistent exogenous substances such as parabens, bisphenols and phthalates which have been associated with a range of metabolic disorders and disease. It is unclear if exposure remains consistent over time. We investigated change in indicators of EDC exposure between 2009 and 2016 and assessed its consistency between and within individuals over a median follow-up time of 47 months in a sample of Dutch individuals. Of 500 Dutch individuals, two 24 h urine samples were analysed for 5 parabens, 3 bisphenols and 13 metabolites of in total 8 different phthalates. We calculated per-year differences using meta-analysis and assessed temporal correlations between and within individuals using Spearman correlation coefficients, intra-class correlation coefficients (ICC) and kappa-statistics. We found a secular decrease in concentrations of methyl, ethyl, propyl and n-butyl paraben, bisphenol A, and metabolites of di-ethyl phthalate (DEP), di-butyl phthalate (DBP), di-(2-ethyl-hexyl) phthalate (DEHP), and butylbenzyl phthalate (DBzP) which varied from 8 to 96% (ethyl paraben, propyl paraben) between 2009 and 2016. Within-person temporal correlations were highest for parabens (ICC: 0.34 to 0.40) and poorest for bisphenols (ICC: 0.15 to 0.23). For phthalate metabolites, correlations decreased most between time periods (ICC < 48 months: 0.22 to 0.39; ≥48 months: 0.05 to 0.32). When categorizing EDC concentrations, 33-54% of individuals remained in the lowest or highest category and temporal correlations were similar to continuous measurements. Exposure to most EDCs decreased between 2009 and 2016 in a sample of individuals with impaired fasting glucose from the Dutch population. Temporal consistency was generally poor. The inconsistency in disease associations may be influenced by individual-level or temporal variation exhibited by EDCs. Our findings call for the need for repeated measurements of EDCs in observational studies before and during at-risk temporal windows for the disease.

The role of epigenetics in the reproductive toxicity of environmental endocrine disruptors

Environmental endocrine disruptors (EEDs) seriously endanger human health by interfering with the normal function of reproductive systems. In males, EEDs can affect sperm formation and semen quality as well spermatogenesis, ultimately reducing fertility. In females, EEDs can affect uterine development and the expression levels of reproduction-related genes, ultimately reducing female fertility and the normal development of the fetus. There are a large number of putative mechanisms by which EEDs can induce reproductive toxicity, and many studies have shown the involvement of epigenetics. In this review, we summarize the role of DNA methylation, noncoding RNAs, genomic imprinting, chromatin remodeling and histone modification in the reproductive toxicity of EEDs.

Predictors of phthalate metabolites in urine and follicular fluid and correlations between urine and follicular fluid phthalate metabolite concentrations among women undergoing in vitro fertilization

BACKGROUND

Phthalate metabolites in follicular fluid (FF) may negatively affect normal folliculogenesis; however, the predictors of phthalate metabolite concentrations in urine and FF and relationships between urine and FF phthalate metabolite concentrations among women undergoing in vitro fertilization (IVF) are poorly understood.

OBJECTIVE

To investigate predictors of phthalate metabolites in urine and FF and correlations between urine and FF phthalate metabolite concentrations among women undergoing IVF.

METHOD

We recruited 305 women seeking infertility treatment at a reproductive center in Wuhan, China, from October to November 2016. Information regarding demographic characteristics, personal care product use and plastic material contact was obtained through direct interviews. Concentrations of 8 phthalate metabolites in urine and FF samples were measured using high-performance liquid chromatography and tandem mass spectrometry. Associations regarding metabolite concentrations in urine and FF samples were analysed by Spearman's correlation and linear regression. Generalized linear regression was used to examine potential predictors of phthalate metabolite concentrations in urine and FF.

RESULTS

Weak to moderate associations between urine and FF samples were found for monoethyl phthalate (MEP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) (correlation coefficient: MEP, 0.350; MEOHP, 0.377); no associations were observed for other metabolites. The predictive powers of urinary metabolite concentrations in determining FF metabolite concentrations were uniformly low, with R² ≤ 0.113. Body mass index (BMI) and educational level were inversely associated with the urinary concentrations of certain metabolites. Higher household income, intake of bottled drinks within 48 h, and use of shower gel and soap were frequently associated with higher urinary metabolite concentrations. BMI, higher household income and use of disposable plastic cups within 48 h were associated with higher metabolite concentrations in FF.

CONCLUSION

Phthalate metabolite concentrations in urine and FF vary according to sociodemographic characteristics and lifestyle factors. Phthalate metabolite concentrations in urine may not be appropriate for estimating ovary phthalate exposure.

Association between the exposure to phthalates and adiposity: A meta-analysis in children and adults

BACKGROUND

Exposure to environmental chemicals has become one of the major concerns in the past decades. Phthalates are a family of synthetic organic chemicals used in the manufacture of plastics, solvents, and personal care products. These compounds are considered as endocrine-disrupting compounds (EDCs) since they may interfere with the endocrine system and disrupt its physiologic function.

AIM

The purpose of this work is to synthesize results from published literature on the association between the exposure to phthalates and adiposity in adults and children.

METHODS

We searched PubMed from inception up to 01 August 2019, to retrieve original papers reporting data on the association between EDCs and adiposity, using the following search expression: (("Endocrine disruptor" OR Endocrine disruptor[mh] OR phthalate) AND (Obesity OR Overweight OR BMI OR "Body fat" OR Adipose tissue[mh] OR Body size[mh] OR "body size" OR "body weight" OR Anthropometry OR "anthropometric measures")) AND (humans[mh]). The study variables and characteristics were collected during data extraction, namely the study design, sample, exposure, outcome, descriptive and association measures. Study quality was assessed using the STROBE template for observational studies. Although studies examined several adiposity measures, Body Mass Index (BMI) and Waist Circumference (WC) were the most commonly used, therefore, we used the beta coefficients regarding BMI and WC, and odds ratios when BMI outcome was categorical to perform the meta-analysis. Data from the studies were combined using fixed effects meta-analyses to compute summary regression coefficients or odds ratios and corresponding 95% confidence intervals (95% CI). Heterogeneity between studies was assessed by the I2 statistic.

RESULTS

In the systematic review we found 29 publications addressing the association between phthalate compounds and adiposity. The vast majority of the included studies reported associations that were not statistically significant. For most of the phthalate compounds there were few studies providing compatible measures and therefore it was not possible to combine the results in a meta-analysis. Both for BMI and WC, the meta-analysis for MiBP, MCPP and MbzP showed negative associations and null association for MBP in children, although none of them was significant. For MEP, positive but not significant associations were found both in children and adults. Conversely, for MEHP a negative association was found also in children and adults although it did not reach statistical significance. Only for MECPP a significant association was found for obesity in adults (OR = 1.67 (95% CI 1.30; 2.16).

CONCLUSION

In general, a positive association between phthalates and adiposity measures was found, especially in adults. However, most of the results did not reach statistical significance and the inconsistencies found between studies did not allow to reach a definitive conclusion. Additionally, we cannot exclude a possible effect of publication bias.

Association between phthalate exposure and glycosylated hemoglobin, fasting glucose, and type 2 diabetes mellitus: A case-control study in China

Epidemiological studies have shown that exposure to phthalates (PAEs) is associated with type 2 diabetes mellitus (T2DM) and related markers, but limited evidence has been found in Chinese people. Given that China has the highest number of people with DM and Chinese people show relatively higher exposure levels of PAEs, a case-control study was conducted in China to explore the associations of PAE exposure with T2DM and two glycemic indicators, including fasting glucose and glycosylated hemoglobin (HbA1c). Two hundred fifty people with T2DM and 250 controls were recruited in this study. Multivariable logistic regression analyses showed significant positive associations between urinary concentrations of most studied PAE metabolites (mPAEs) and T2DM, with odd ratios comparing extreme mPAEs quartiles ranging from 2.09 to 40.53, whereas two secondary metabolites, mono (2-ethyl-5-carboxypentyl) phthalate and mono [(2-carboxymethyl) hexyl] phthalate showed significant inverse relationships with T2DM. In addition, multivariable linear regression analyses showed that urinary concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate were positively associated with HbA1c levels in controls (β = 0.013; 95% CI: 0.003, 0.023). A significant positive association was also observed for urinary mono (2-ethylhexyl) phthalate and fasting glucose (β = 0.009; 95% CI: 0.002, 0.016). In the stratified analyses, the significant associations of mPAEs with T2DM were more likely to be observed in the younger people, compared to the older people. The significant positive associations between urinary mPAEs and HbA1c levels were more likely to be found in the lower body mass index (BMI) subgroup. Additionally, urinary specific mPAEs were found to be significantly positively related to fasting glucose in males and the older people. The findings suggest that exposure to PAEs is associated with T2DM, fasting glucose, and HbA1c levels in Chinese people and the associations of exposure to PAEs with T2DM, fasting glucose, and HbA1c may differ between sexes, BMIs, or ages.

The extent and predictors of phthalate exposure among couples undergoing in vitro fertilization treatment

Phthalates are chemicals used as plasticizers and solvents in many consumer products but are suspected of disrupting the endocrine system and are known for their reproductive/developmental health risks. This study examined the extent and predictors of phthalate exposure among 599 couples undergoing in vitro fertilization. A questionnaire was administered to obtain sociodemographic, health, and lifestyle data, and two spot urine samples were collected from the couples to analyze eight phthalate metabolites, cotinine (COT) as a smoking index, and creatinine to adjust for urine dilution. Seven phthalate metabolites were detected in > 94% of the urine samples, and monobenzyl phthalate (MBzP) was found in 24% of the women and 26% of their male partners. Median phthalate levels were highest for monoethyl phthalate (MEP), at 333.26 μg/l in women and 290 μg/l in male partners, and lowest for MBzP, at 1.17 μg/l in women and 1.14 μg/l in male partners. Correlation coefficients of ≥ 0.4 between the women and their male partners for the eight urinary phthalate metabolites may indicate a shared source of exposure. A multivariate regression model was used to assess the association between predictors and each urinary phthalate metabolite. Several potential predictors for the variations in specific urinary phthalate metabolites were identified, including the body mass index, age, socioeconomic status, and regional distribution for both women and their male partners but with slightly different patterns. Women with a history of breastfeeding, using bottled water for cooking and storing food in plastic bags had lower MEP (8.7%), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP) (9.2%), and both mono-iso-butyl phthalate and MECPP (8.2 and 8.1%). A history of contraceptive use was associated with an increase in MECPP (8.7%), mono-(2-ethyl-5-hydroxyhexyl) phthalate (11.4%), mono-(2-ethyl-5-oxohexyl) phthalate (7.6%), and the molar sum of bis (2-ethylhexyl) phthalate metabolites (8.9%). Urinary COT levels were associated with an increase of 10-16% in all urinary metabolites in women but of only 10.5% in mono-(2-ethylhexyl) phthalate in male partners. More than 95% of the couples reported the use of cosmetics, perfumes, and personal-care products, but we were not able to find associations with urinary phthalate metabolites, perhaps due to their short half-lives. MEP levels associated with the use of household cleaning products were 11.2% higher in male partners. Our levels were generally higher than those reported elsewhere, perhaps due to different lifestyles, cultural practices, dietary habits, use of personal-care products, and governmental legislation.

Nine phthalate metabolites in human urine for the comparison of health risk between population groups with different water consumptions

Phthalates are a group of high production volume chemicals widely detected in environment matrix and human specimens. Potential health risks due to the prevalence of their exposure through water consumption and the endocrine-disrupting activities have become an important issue. This work aims to compare the distributions of phthalate levels and potential health risks caused by phthalate exposure among three groups of participants ingesting different types of water. Here, a method with good performance was applied for the analysis of nine common phthalate metabolites in 125 human urine samples collected from Wuhan women. Seven analytes (mono‑ethyl, mono‑benzyl, mono‑n‑butyl, mono‑(2‑ethylhexyl), mono‑(2‑ethyl‑5‑oxohexyl), mono‑(2‑ethyl‑5‑hydroxyhexyl), and mono‑(2‑ethyl‑5‑carboxypentyl) phthalate) were detected in over 80% of the samples. By measuring urinary concentrations of phthalate monoesters, the exposure levels of respective parent phthalates, exposure patterns, the estimated daily intakes and accumulative risk assessments were investigated in three groups of participants consuming water from different sources (bottled water, filtered water and boiled tap water). The results showed that the exposure patterns of phthalates varied among the population groups with different water intakes, and the health risk was higher for people ingesting the boiled tap water than that of the groups consuming bottled water (purified water) and filtered water with filter cartridge containing activated carbon.

Personal care products use and phthalate exposure levels among pregnant women

BACKGROUND

Fetuses are susceptible to phthalates, known endocrine disrupting chemicals, within sensitive windows of development. It is crucial to determine the major sources of phthalates to reduce exposure. This study aims to examine the associations between usage patterns of personal care products (PCPs) and urinary levels of phthalate metabolites across pregnancy in a multi-hospital based birth cohort.

METHODS

During 2012-2015, we conducted a birth cohort study named the Taiwan Mother Infant Cohort Study (TMICS). Usage patterns of PCPs were obtained using structured questionnaires during the third trimester of pregnancy. Spot urine samples were collected at each trimester, and levels of eleven phthalate metabolites were measured by liquid chromatography tandem mass spectrometry. The association of PCPs use with urinary phthalate metabolite concentrations was assessed using GEE models.

RESULTS

Among the 1676 pregnant women participated in TMICS, 281 who provided two or three urine samples across pregnancy were included. The levels of several phthalate metabolites were significantly associated with the use of PCPs, particularly leave-on PCPs. With the increasing use of skin toners (11.7%; 95% CI: 1.5%, 22.9%), lipsticks (13.2%; 95% CI: 4.6%, 22.5%), and essential oils (21.8%; 95% CI: 9.1%, 36.0%), individuals are exposed to higher concentrations of mono-ethyl phthalate (MEP). Additionally, a positive trend was found regarding the number of leave-on PCPs used and the measured change in MEP concentrations (P for trend = 0.01). Other positive associations included MBzP and body lotions (7.9%; 95% CI: 0.1%, 16.2%). With regard to rinse-off PCPs, we found a positive association between urinary MBzP and shampoo use, and a negative association between urinary MMP and face wash.

CONCLUSION

Leave-on PCPs were found to be a more probable source of phthalate exposure than the use of rinse-off PCPs. We suggest pregnant women reduce the frequency of leave-on PCPs use during pregnancy to avoid such phthalate exposure.

Urinary Phthalate Metabolite Concentrations and Breast Cancer Incidence and Survival following Breast Cancer: The Long Island Breast Cancer Study Project

BACKGROUND

Phthalates, known endocrine disruptors, may play a role in breast carcinogenesis. Few studies have examined phthalates in relation to breast cancer (BC), and, to our knowledge, none have considered survival following BC.

OBJECTIVES

We examined 11 urinary phthalate metabolites, individually and as molar sum groupings, in association with BC incidence and subsequent survival.

METHODS

Our study includes 710 women diagnosed with first primary BC in 1996-1997 and 598 women without BC from Long Island, New York. Within 3 mo of diagnosis, participants provided spot urine samples. Nine phthalate metabolites were measured in all women; two [monocarboxyoctyl phthalate (MCOP) and monocarboxy-isononyl phthalate (MCNP)] were measured in 320 women with and 205 without BC. Women with BC were followed since diagnosis using the National Death Index; during follow-up (median=17.6 y), we identified 271 deaths (98 BC related). We examined creatinine-corrected metabolite concentrations in association with: BC, using logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and all-cause/BC-specific mortality, using Cox regression to estimate hazard ratios (HRs) and 95% CIs. We also examined effect modification by body mass index (BMI) and estrogen receptor (ER) status.

RESULTS

The highest (vs. lowest) quintiles of mono(3-carboxypropyl) phthalate (MCPP), monobenzyl phthalate (MBzP), MCNP, and MCOP were associated with BC ORs ranging from 0.71-0.73. The highest (vs. lowest) quintiles of mono(2-ethylhexyl) phthalate (MEHP) and MCOP were associated with BC-specific mortality HRs of 0.54 (95% CI: 0.28, 1.04) and 0.55 (95% CI: 0.23, 1.35), respectively. For BC-specific mortality, interactions were significant between BMI and mono(2-ethyl-5-oxyhexyl) phthalate (MEOHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), with positive associations among women with BMI<25 and inverse associations among women with BMI≥25.0 kg/m².

CONCLUSIONS

Consistent with laboratory evidence, we observed inverse associations between urinary concentrations of several phthalate metabolites and BC and subsequent survival; however, these results should be interpreted with caution given that biospecimen collection among women with BC occurred after diagnosis, which may be of particular concern for our case-control findings. https://doi.org/10.1289/EHP2083.

Prevalence and Social Risk Factors for Hearing Impairment in Chinese Children-A National Survey

Hearing impairment may affect children’s communication skills, social development, and educational achievement. Little is known about the prevalence of hearing impairment among Chinese children. Data were taken from the 2006 second China National Survey on Disability (CNSD). Hearing impairment was defined as moderate (41–60 dB HL), severe (61–80 dB HL), profound (81–90 dB HL), or complete (>91 dB HL). Logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI). A weighted number of 567,915 hearing impairment children were identified, yielding a prevalence of 17.49 per 10,000 people (95% CI: 16.90–18.08), with prevention or treatment options possible for 64.6% of hearing impairment children. The main causes of hearing impairment were hereditary, tympanitis, and drug intoxication. Illiteracy in one or both parents (mother: OR = 1.388, 95% CI: 1.125–1.714, p < 0.0001; father: OR = 1.537, 95% CI: 1.152–2.049, p < 0.0001 relative to no school or primary school), annual family income lower than national average (OR = 1.323, 95% CI: 1.044–1.675, p = 0.0203, relative to higher than national average), household size larger than three people (OR = 1.432, 95% CI: 1.164–1.762, p = 0.0007, relative to smaller than three people) and single-mother family (OR = 2.056, 95% CI: 1.390–3.042, p = 0.0176, relative to intact family) were the independence risk factors for hearing impairment among Chinese children. Lower annual family income, male children, larger household size, single-mother family, and lower levels of maternal and paternal education were independent risk factors for hearing impairment for Chinese children. Further studies on hearing impairment prevention and the relationship between parental social factors and the risk of hearing impairment are needed.

Prevalence and Parental Risk Factors for Speech Disability Associated with Cleft Palate in Chinese Children-A National Survey

Although the prevalence of oral clefts in China is among the highest worldwide, little is known about the prevalence of speech disability associated with cleft palate in Chinese children. The data for this study were collected from the Second China National Sample Survey on Disability, and identification of speech disability associated with cleft palate was based on consensus manuals. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A weighted number of 112,070 disabled children affected by cleft palate were identified, yielding a prevalence of 3.45 per 10,000 children (95% CI: 3.19–3.71). A history of speech disability in the mother (OR = 20.266, 95% CI 5.788–70.959, p < 0.0001), older paternal child-bearing age (OR = 1.061, 95% CI 1.017–1.108, p = 0.0065, per year increase in age), and lower parental education (maternal: OR = 3.424, 95% CI 1.082–10.837, p = 0.0363; paternal: OR = 2.923, 95% CI 1.245–6.866, p = 0.0138) were strongly associated with risk of speech disability associated with cleft palate in the offspring. Our results showed that maternal speech disability, older paternal child-bearing age, and lower levels of parental education were independent risk factors for speech disability associated with cleft palate for children in China. These findings may have important implications for health disparities and prevention.

Associations of individual characteristics and lifestyle factors with metabolism of di-2-ethylhexyl phthalate in NHANES 2001-2012

BACKGROUND

Previous studies suggest that a higher ratio of primary to secondary metabolites of di-2-ethylhexyl phthalate (DEHP), reflective of a slower DEHP conversion rate, is associated with a greater physiologic effect. We examined associations of several individual characteristics and lifestyle factors with the ratio of mono-2-ethylhexyl phthalate to mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHP:MEHHP) and %MEHP (the ratio of MEHP to the sum of the secondary metabolites).

METHODS

We used the data from the National Health and Nutrition Examination Survey, 2001-2012. The study included adults with BMI<30 and no diabetes. Pregnant women were excluded. We examined associations of age, race, gender, Body Mass Index, smoking, alcohol and caffeine consumption, medication use, cancer history, and menopausal status and postmenopausal hormone use (in women) with MEHP:MEHHP and %MEHP using multivariable linear regression. The values for %MEHP were log-transformed in the analysis.

RESULTS

In multivariable analysis, non-Caucasian individuals had higher %MEHP (non-Hispanic Blacks: β=0.114, 95% Confidence interval [CI]: 0.050, 0.177; Hispanic: β=0.089, 95% CI: 0.024, 0.154; other race: β=0.126, 95% CI: 0.033, 0.219). Age was inversely associated with MEHP:MEHHP (β=-0.001, 95% CI: -0.002, -0.001) and %MEHP (β=-0.006, 95% CI: -0.008, -0.004). Overweight individuals had lower MEHP: MEHHP and lower %MEHP (β=-0.035, 95% CI: 0.062, -0.008 and β=-0.104, 95% CI: -0.162, -0.046, respectively). Alcohol consumption was inversely associated with %MEHP among men (p-trend=0.03).

CONCLUSIONS

Individual and lifestyle characteristics are associated with differences in DEHP metabolism. Understanding underlying biological mechanisms could help to identify individuals at a greater risk of adverse effects from DEHP exposure.

The association between phthalates and metabolic syndrome: the National Health and Nutrition Examination Survey 2001-2010

BACKGROUND

Higher exposure to certain phthalates is associated with a diabetes and insulin resistance, with sex differences seen. Yet, little is known about the association between phthalates and metabolic syndrome (MetS), particularly with consideration for differences by sex and menopausal status.

METHODS

We analyzed data from 2719 participants in the National Health and Nutrition Examination Survey (NHANES) 2001-2010 aged 20-80 years. Five urinary phthalate metabolites (MEP, MnBP, MiBP, MBzP, and MCPP) and DEHP metabolites were analyzed by the Centers for Disease Control and Prevention and were evaluated as population-specific quartiles. MetS was defined by National Cholesterol Education Program's Adult Treatment Panel III report criteria. Prevalence odds ratios (POR) and 95 % confidence intervals (CI) were calculated using multivariable logistic regression, adjusting for potential confounders and stratifying by sex and menopausal status.

RESULTS

Participants with MetS (32 % of the study population) had higher concentrations for all urinary phthalate metabolites. After full adjustment, higher DEHP metabolite concentrations were associated with an increased odds of MetS in men, but not women (adj. POR for men Q4 versus Q1: 2.20; 95 % CI: 1.32, 3.68 and adj. POR for women Q4 versus Q1: 1.50; 95 % CI: 0.89, 2.52). When evaluating by menopausal status, pre-menopausal women with higher concentrations of MBzP had close to a 4-fold increased odds of MetS compared to pre-menopausal women with the lowest concentrations of MBzP (adj POR: Q4 versus Q1: 3.88; 95 % CI: 1.59, 9.49).

CONCLUSIONS

Higher concentrations of certain phthalate metabolites were associated with an increased odds of MetS. Higher DEHP metabolite concentrations were associated with an increased odds of MetS for men. In women, the strongest association was between higher concentrations of MBzP and MetS, but only among pre-menopausal women.