Maternal phthalate exposure and BMI trajectory in children-an 18-year birth cohort follow-up study

BACKGROUND

Obesity is a major health concern worldwide. Previous studies have suggested that phthalate plasticizers are obesogens. However, the relationship between early-life phthalate exposure and long-term obesity development remains unknown.

OBJECTIVE

We investigated the association between prenatal phthalate exposure and children's body mass index (BMI) patterns in an 18-year birth cohort follow-up study in Taiwan.

METHODS

Our analytical lab quantified seven phthalate metabolites in maternal urine during pregnancy using quantitative liquid chromatography-tandem mass spectrometry. In addition, we calculated BMI z scores for participated children at each follow-up, utilized trajectory analysis to describe children's BMI z-score patterns at 2-18 years of age, and adopted generalized estimating equations (GEE) and multivariate logistic regression models to assess the association between prenatal phthalate exposure and BMI z scores in children.

RESULTS

A total of 208 mother-child pairs were included in the analysis. Maternal urinary diethyl phthalate (DEP) metabolites were associated with the increase of BMI z scores in children aged 2-18 years in the GEE model. Doubled maternal urinary ∑mDEHP (3 mono hexyl-metabolites of di-ethyl-hexyl phthalate (DEHP) increased the risk of children being in the stable-high BMI trajectory group until the age of eighteen.

IMPACT STATEMENT

We observed that BMI trajectories of children remained stable after the age of 5 years. During each follow-up, a higher frequency of overweight or obese was observed in children, ranging from 15.9% to 35.6% for girls and 15.2-32.0% for boys, respectively. Prenatal phthalate exposure was associated with increasing BMI z scores in children. Prenatal DEHP exposure was associated with a stable-high BMI trajectory in children up to the age of 18 years.

Prenatal phthalate exposure and sex steroid hormones in newborns: Taiwan Maternal and Infant Cohort Study

BACKGROUND

Newborn anogenital distance (AGD) has been associated with prenatal exposure of phthalates. The association between prenatal phthalate exposure and sex steroid hormones in newborns is unclear.

OBJECT

This study aimed to examine whether cord-blood sex hormone levels were associated with prenatal phthalate exposure and newborn anogenital distance (AGD).

METHODS

In the Taiwan Maternal and Infant Cohort Study, we recruited 1,676 pregnant women in their third trimester in 2012-2015 in Taiwan. We determined 11 urinary phthalate metabolites in pregnant women, three maternal and five cord-blood steroid sex-hormone concentrations. Five hundred and sixty-five mother-infant pairs with sufficient data were included. Trained neonatologists measured 263 newborns' AGD. We examined the associations of prenatal phthalate metabolite levels with AGD and hormones using linear regression models and evaluated correlations between maternal and cord-blood sex hormone levels and AGD.

RESULTS

Compared with the male newborns exposed to maternal phthalate metabolites at the first tertile, AGD was -3.75, -3.43, and -3.53 mm shorter among those exposed at the median tertile of di-2-ethylhexyl phthalate (DEHP) metabolites, monobenzyl phthalate (MBzP), and monomethyl phthalate (MMP), respectively. Compared with those who had exposed at the first tertile, cord-blood follicle-stimulating hormone (FSH) decreased among male newborns exposed at higher levels of MMP, mono-n-butyl phthalate (MnBP), MBzP and DEHP, and among female newborns exposed at higher levels of MMP, MBzP and mono(2-ethyl-5-hydroxyhexyl) phthalate. However, we did not observe significant correlations of maternal or cord-blood sex steroid hormones with newborns' AGDs.

CONCLUSIONS

Alterations in cord-blood sex steroid hormone levels were associated with prenatal phthalate exposures, particularly in male newborns. Women aspiring to be pregnant should be alerted of the need of reducing phthalate exposure.

Sex-specific interactive effect of melamine and DEHP on a marker of early kidney damage in Taiwanese adults: A national population-based study from the Taiwan Biobank

Taiwan had the high incidence of chronic kidney disease (CKD) worldwide. Our objective was to examine associations between daily exposure of phthalates and melamine, two common nephrotoxins, and kidney damage risk in a well-established nationwide cohort. Study subjects were from Taiwan Biobank (TWB) with existing data of questionnaire and biochemical examinations. Average daily intake (ADI) levels of melamine and seven parental phthalates, including DEHP (di-2-ethylhexylphthalate), DiBP (Dibutyl phthalate), DnBP (Di-n-butyl phthalate), BBzP (Butyl benzyl phthalate), DEP (Diethyl phthalate), and DMP (Dimethyl phthalate) were estimated using a creatinine excretion-based model from urine melamine and 10 phthalate metabolites. Urine microalbumin to creatinine ratio (ACR) was used to represent for the outcome of kidney damage. Two statistical strategies were used: First, a weighted quantile sum (WQS) regression model to select the most important exposure variables of ADI levels of phthalates and melamine associated with ACR; Second, to examine effects of those most important exposure variables on ACR in multivariable linear regression models. In total, 1153 eligible adults were left for analyses. Of them, 591 (51.3%) and 562 (48.7%) were men and women, respectively, with a median age of 49 years old. By WQS, a significant and positive association was found between ADI of melamine and phthalates and ACR (β = 0.14, p = 0.002). ADI levels of melamine had the highest weight (0.57), followed by DEHP (0.13). Next, examining the two most important exposures in association with ACR, we found that the higher the melamine and DEHP intakes, the higher the ACR levels were found. An interaction effect was also found between melamine and DEHP intakes on urine ACR (p = 0.015). This result was more prominent in men (p = 0.008) than in women (p = 0.651). Environmental co-exposure of melamine and DEHP can potentially affect ACR in the community-dwelling Taiwanese adult population.

Maternal di-(2-ethylhexyl) phthalate exposure elicits offspring IFN-λ upregulation: Insights from birth cohort, murine model, and in vitro mechanistic analysis

Maternal exposure to di-(2-ethylhexyl)-phthalate (DEHP), an environmental endocrine disruptor, may lead to developmental immunotoxicity in offspring. The causal relationship and underlying mechanism require further study. A subset of Taiwan Maternal and Infant Cohort Study data (n = 283) was analyzed and found a significant association between urinary DEHP metabolite levels from the third trimester of pregnancy and plasma levels of IL-28A and IL-29, named IFNλs, in cord blood. A trans-maternal murine model mimicking human DEHP exposure way showed that bone marrow-derived dendritic cells from maternal DEHP-exposed F1 offspring secreted higher IL-28A levels than control cells, indicating a potential causal relationship. Human bronchial epithelial cell lines treated with DEHP or its primary metabolite, mono-(2-ethyl-5-hexyl) phthalate (MEHP), expressed significantly higher levels of IFNλs mRNA or protein than controls. MEHP's effect on IFNλs expression was blocked by peroxisome proliferator-activated receptor α (PPARα) and PPARγ antagonists, and inhibited by a histone acetyltransferase inhibitor or a histone methyltransferase inhibitor. Chromatin immunoprecipitation assay showed that MEHP treatment promoted histone modifications at H3 and H4 proteins at the promoter regions of Il28a and Il29 genes. These results suggest maternal DEHP exposure could result in high IFNλ expression in offspring, and the health risk of early-life exposure requires further investigation.

Di(2-ethylhexyl) phthalate mediates IL-33 production via aryl hydrocarbon receptor and is associated with childhood allergy development

Background

Few studies assess cord blood biomarkers to predict prenatal exposure to di(2-ethylhexyl) phthalate (DEHP) on the development of allergic diseases later in childhood. IL-33 has been indicated to play an important role in allergic diseases. We evaluated the association of prenatal DEHP exposure and IL-33 in cord blood on the development of allergic diseases. We also investigated the mechanism of DEHP in human lung epithelial cells and asthma animal models.

Methods

66 pregnant women were recruited, and their children followed when they were aged 3 years. Maternal urinary DEHP metabolites were determined using liquid chromatography-electrospray-ionization-tandem mass spectrometry. The effect of DEHP on IL-33 production was investigated in human lung epithelial cells and club cell-specific aryl hydrocarbon receptor (AhR) deficiency mice. ELISA and RT-PCR, respectively, measured the IL-33 cytokine concentration and mRNA expression.

Results

The concentrations of maternal urinary DEHP metabolites and serum IL-33 in cord blood with childhood allergy were significantly higher than those in the non-childhood allergy group. DEHP and MEHP could induce IL-33 production and reverse by AhR antagonist and flavonoids in vitro. Enhanced ovalbumin-induced IL-4 and IL-33 production in bronchoalveolar lavage fluid (BALF) by DEHP exposure and suppressed in club cell-specific AhR null mice. Kaempferol has significantly reversed the DEHP effect in the asthma animal model.

Conclusions

Cord blood IL-33 level was correlated to childhood allergy and associated with maternal DEHP exposure. IL-33 might be a potential target to assess the development of DEHP-related childhood allergic disease. Flavonoids might be the natural antidotes for DEHP.

Associations of urinary phthalate metabolites with household environments among mothers and their preschool-age children

Phthalates have become a matter of public health concern due to their extensive use worldwide and negative health effects. The evaluation of potential sources of phthalate exposure is crucial to design prevention strategies, especially for vulnerable populations. This study included 528 mother-child pairs in the Taiwan Mother Infant Cohort Study who were followed up at ages 3-6 years between 2016 and 2020. Each mother was interviewed by using a structured questionnaire containing questions on demographic characteristics and household environment factors, such as the use of plastic food packaging, residential visible mold, insecticide sprays, and electric mosquito repellents. Eleven phthalate metabolites were analyzed in urine samples simultaneously collected from the mother-child pairs. The phthalate metabolite urinary concentrations were higher among the children than among their mothers, except those of mono-ethyl phthalate (MEP) and mono-2-ethylhexyl phthalate (MEHP). Multiple linear regression analyses showed that urine samples collected during the summer showed higher concentrations of phthalate metabolites than those collected during the winter. Family income levels had negative associations with the concentrations of MnBP and metabolites of di-2-ethylhexyl phthalate (DEHP) in children. The use of plastic food packaging was positively associated with mono-n-butyl phthalate (MnBP) and metabolites of DEHP in mothers. Residential visible mold or mold stains were significantly associated with higher MnBP and DEHP metabolite concentrations in children. The use of insecticide sprays was positively associated with MnBP concentrations in children. Significant associations between household environmental factors and phthalate exposure were mostly found in children, potentially indicating different exposure pathways between mothers and their children. Findings from this study provide additional information for the design of prevention strategies to protect the health of children and women.

Prenatal DEHP exposure predicts neurological disorders via transgenerational epigenetics

Recent experimental and observational research has suggested that childhood allergic asthma and other conditions may be the result of prenatal exposure to environmental contaminants, such as di-(2-ethylhexyl) phthalate (DEHP). In a previous epidemiological study, we found that ancestral exposure (F0 generation) to endocrine disruptors or the common plasticizer DEHP promoted allergic airway inflammation via transgenerational transmission in mice from generation F1 to F4. In the current study, we employed a MethylationEPIC Beadchip microarray to examine global DNA methylation in the human placenta as a function of maternal exposure to DEHP during pregnancy. Interestingly, global DNA hypomethylation was observed in placental DNA following exposure to DEHP at high concentrations. Bioinformatic analysis confirmed that DNA methylation affected genes related to neurological disorders, such as autism and dementia. These results suggest that maternal exposure to DEHP may predispose offspring to neurological diseases. Given the small sample size in this study, the potential role of DNA methylation as a biomarker to assess the risk of these diseases deserves further investigation.

Co-exposure to toxic metals and phthalates in pregnant women and their children's mental health problems aged four years - Taiwan Maternal and Infant Cohort Study (TMICS)

BACKGROUND

Childhood and adolescent mental health problems may increase the global burden of disease. Neurotoxic metals are associated with inflammation and cytotoxicity in the brain. In addition, prenatal phthalate ester (PAE) exposure is associated with cognitive function deficits. However, the effect of co-exposure to toxic metals, PAEs, and their association with child behavior is less well studied. Hence, we aimed to investigate prenatal co-exposure to the metals and PAEs and the consequent behavioral outcomes in early childhood.

METHODS

We followed pregnant women and their newborns from the Taiwan Maternal and Infant Cohort Study between 2015 and 2017, with a focus on women from the central, southern, and eastern areas of Taiwan. We quantified maternal urinary concentrations of metals and metabolites of PAEs as surrogates of prenatal exposure. We recorded the Child Behavior Checklist scores according to caregiver reports at 4 years of age, and identified Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)-oriented problems.

RESULTS

Ultimately, 408 children were included in the statistical analysis. Maternal urinary copper levels were significantly associated with depressive problems (odds ratio [OR] = 2.13) in children. Maternal urinary concentrations of mono-n-butyl phthalate (MnBP) and mono-isobutyl phthalate (MiBP) were also significantly associated with depressive symptoms (odds ratio [OR] = 1.51 and 1.53, respectively). Further analysis considering prenatal co-exposure to metals and PAEs showed that co-exposure to these materials was significantly associated with autism spectrum problems (OR = 3.11).

CONCLUSIONS

We observed that prenatal single exposure or co-exposure to metals and PAEs may play a role in some DSM-5-oriented problems in children at 4 years of age. Reduction of exposure to toxic metals and PAEs in pregnancy is suggested to prevent increased mental health problems in children.

Associations between maternal phthalate exposure and neonatal neurobehaviors: The Taiwan maternal and infant cohort study (TMICS)

Previous studies have shown associations between prenatal phthalate exposure and neurobehavioral changes in children. However, few studies have focused on neonatal neurobehavioral development. This study aimed to examine the associations between prenatal phthalate exposure and neonatal neurobehavioral development in the early days of life after birth. This cohort study included 283 mother-infant pairs who participated in the Taiwan Mother Infant Cohort Study during 2012-2015. Each mother was interviewed, and urine samples were collected during the third trimester of pregnancy (weeks 29-40). Eleven common phthalate metabolites in maternal urine were analyzed. The Chinese version of the Neonatal Neurobehavioral Examination was used to evaluate early infant neurobehavioral development within five days of birth. We performed multiple linear regressions to explore the associations between phthalate exposure and neonatal neurobehavioral development. Sex differences in the association between phthalate metabolites and neonatal neurobehaviors were noted. Among girls, tertiles of phthalate metabolite concentrations were associated with worse behavioral responses and tone and motor patterns in the high-molecular-weight phthalate (HMW) and low-molecular-weight phthalate (LMW) groups. Girls in the highest tertile of di-2-ethylhexyl phthalate (DEHP) and mono-isobutyl phthalate (MiBP) had a negative association with tone and motor patterns. Girls in the highest tertile of mono-n-butyl phthalate (MnBP) and MiBP showed a negative association with behavioral responses. In contrast, tertiles of phthalate metabolite exposure were associated with improved neurobehaviors in mono-methyl phthalate (MMP) among boys. The highest tertile of MMP was positively associated with behavioral responses, primitive reflexes, and tone and motor patterns. Our findings suggest that maternal phthalate exposure affects neonatal neurobehavioral development in a sex-specific manner. Despite the relatively small sample size, our findings add to the existing research linking maternal phthalate exposure to neonatal neurobehavioral development. Additional research is needed to determine the potential long-term effects of prenatal phthalate exposure on children.

Reference intervals for thyroid hormone, sex hormone, and clinical biochemical tests in cord blood from Taiwanese newborn - TMICS cohort

BACKGROUND/PURPOSE

This study aims to establish reference intervals for important biochemical parameters in cord blood of newborn male and female infants in Taiwan and to investigate their sex difference. We also examined the correlation of the same markers between maternal blood levels and neonatal cord blood levels.

METHODS

2,136 pregnant women receiving regular routine prenatal health assessments in their third trimester (weeks 29-40) were recruited from nine hospitals in Taiwan between 2012 and 2015. After exclusion, we were left with 580 cord blood samples to include in this study.

RESULTS

Cord blood thyroid-stimulating hormone was higher in males than females (p < 0.05). Males also had significantly higher sex hormone levels (estradiol, follicle-stimulating hormone, and sex hormone-binding globulin), while females had higher levels of luteinizing hormone. Male newborns had higher cord blood immunoglobulin E (IgE), while females had higher insulin-like growth factor-1 (IGF-1) levels. We found a slight positive link between maternal blood and cord blood in thyroid hormones and sex hormones.

CONCLUSION

This study found sex differences in cord blood thyroid hormone, sex hormone, IGF-1, and IgE levels and a link between maternal blood levels of thyroid and sex hormones and those in the cord blood of their infants.

Exposure Characteristics and Cumulative Risk Assessment for Phthalates in Children Living near a Petrochemical Complex

BACKGROUND

School-aged children living near plastics-producing factories may have higher risk of exposure to phthalates released during the manufacturing processes.

OBJECTIVES

We aimed to investigate the urinary concentrations of phthalate metabolites in school-aged children living near a petrochemical complex and estimate the cumulative risk of phthalate exposure.

METHODS

We used a well-established cohort (Taiwan Petrochemical Complex Cohort for Children, TPE3C) of school-aged children (6-13 years old) living near polyvinyl chloride (PVC) and vinyl chloride monomer (VCM) factories in central Taiwan from October 2013 to September 2014. A total of 257 children were included from five elementary schools: Syu-Cuo Branch (n = 58, school A, ~0.9 km), Feng-An (n = 40, school B, ~2.7 km), Ciao-Tou (n = 58, school C, ~5.5 km), Mai-Liao (n = 37, school D, ~6.9 km), and Lung-Feng (n = 57, school E, ~8.6 km). We analyzed 11 metabolites of seven phthalates (including di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DnBP)) in urine. Daily intakes (DIs) were compared with acceptable intake levels to calculate the hazard quotient (HQ) for individual phthalates, and the cumulative risk for each child was assessed using a hazard index (HI), which was the sum of the the individual HQs.

RESULTS

The geometric mean and proportion of participants with HIs exceeding one for hepatic (HI_hep) and reproductive (HI_rep) effects were 0.33 (13.2%) and 0.24 (7.8%), respectively. The major contributors to phthalate exposure risk were DEHP, di-iso-butyl phthalate (DiBP) and DnBP in all children. Moreover, we observed a U shaped distribution of DEHP exposure by school distance from the PVC and VCM factories (school A: 7.48 μg/kg/day and school E: 80.44 μg/kg/day). This may be due to emissions (closest) and and being located downwind of PVC scrap incineration (farthest).

CONCLUSIONS

Our findings suggest that children living near a petrochemical complex were at a greater risk of phthalate exposure than normal school-aged children and that phthalate exposure was mainly attributed to DEHP, DiBP and DnBP. In addition, inhalation may have been a risk factor for people living near to PVC and VCM factories.

Benchmark dose in the presence of coexposure to melamine and diethylhexyl phthalate and urinary renal injury markers in pregnant women

Environmental exposures to mixtures of toxic chemicals have potential interaction effects that may lead to hazard index values exceeding one. However, current regulation levels, such as tolerable daily intake (TDI), are mostly based on experimental studies conducted with a single chemical compound. In this study, we assessed the relationships between melamine and di-(2-ethylhexyl) phthalate (DEHP) exposure and their coexposure with the early renal injury markers N-acetyl -D-glucosaminidase (NAG), albumin/creatinine ratio (ACR), and microalbuminuria in 1236 pregnant women. Various generalized linear models with interaction terms and Bayesian kernel machine regression models were used for the (co-)exposure response associations. We derived the benchmark dose (BMD) and the corresponding one-sided 95% confidence bound BMDL based on the estimated (covariate-adjusted) average daily intake of melamine and DEHP metabolites measured in spot urine of the women collected during the third trimester. Given a benchmark response of 0.1, the BMDL level of melamine (DEHP) exposure on NAG (ACR, microalbuminuria) was 2.67 (11.20, 4.45) μg/kg_bw/day, and it decreased to as low as 1.46 (3.83, 2.73) μg/kg_bw/day when considering coexposure to DEHP (melamine) up to the 90th percentile. Both the exposure threshold levels of melamine and DEHP for early renal injuries in pregnant women were several-fold to one order lower than the current recommended TDIs by the WHO and the US FDA and EPA and were even lower considering coexposure. Because of concurrent exposures in real-world environments, more stringent regulation levels are recommended in susceptible populations, such as pregnant women, due to potential synergistic mixture effects.

The sex-specific association of prenatal phthalate exposure with low birth weight and small for gestational age: A nationwide survey by the Taiwan Maternal and Infant Cohort Study (TMICS)

The Taiwan Maternal and Infant Cohort Study (TMICS) was launched with the aim to assess the effects of prenatal exposure to phthalic acid esters (PAEs) on infant health. A total of 1102 pregnant women were enrolled in this study from 2012 to 2015. All participants completed a structured questionnaire, and provided urine specimens. The urinary concentrations of PAE metabolites in the third trimester were measured using liquid chromatography-electrospray ionization tandem mass spectrometry. Generalized additive model-penalized regression splines and logistic regression models were employed to determine the risk for low birth weight (LBW) or small for gestational age (SGA) among pregnant women exposed to PAEs. After adjustments for other covariates, each incremental unit of ln-transformed mono-n-butyl phthalate (MnBP) for pregnant women increased the odds of SGA in male neonates by 1.44 (95% CI: 0.92-2.23). An inverse association between SGA and maternal MnBP exposure level was observed in female neonates. An increase in one ln-transformed MnBP concentration unit decreased the risk of female SGA to 0.50 (95% CI: 0.24-0.97). In the penalized regression splines, increased risks of LBW/SGA in male neonates were presented while pregnant women exposed to increased MnBP levels. However, an association in the opposite direction was observed between maternal MnBP and LBW or SGA for male and female neonates. This study indicated that high maternal MnBP exposure in the third trimester was associated with LBW or SGA for male infants. Adverse effects on susceptible populations exposed to high levels of PAEs should be of concern.

The Chinese Adolescent Cohort Study: Design, Implementation, and Major Findings

The importance of diet quality on children's growth is being increasingly recognized. The Chinese Adolescent Cohort (CAC) is a longitudinal cohort study to comprehensively investigate the health impacts of nutritional factors on child growth. From 2013 to 2018, 6,967 children aged 6-8 years have been recruited from 23 primary schools in Sichuan, Guizhou, and Chongqing, which have been planned to be followed up annually until their age of 15 years. Regular assessments included the measurement of height, weight, waist circumference, and skinfold thicknesses; pubertal development was examined by trained investigators according to Tanner stages; dietary intake was obtained by three 24-h recalls and food frequency questionnaire; validated questionnaires were used to estimate socio-demographic characteristics, physical activity, and sedentary behaviors. Findings from the CAC baseline and the first follow-up data suggested that higher protein intake among girls and unhealthy eating habits among children might increase the risk for childhood obesity. Also, higher intakes of grain and meat and lower overall diet quality and intakes of dietary fiber and tuber might be associated with advanced pubertal development. Those results indicated that the CAC study could contribute to the development of strategies for optimizing Chinese children's health.

Association between two common environmental toxicants (phthalates and melamine) and urinary markers of renal injury in the third trimester of pregnant women: The Taiwan Maternal and Infant Cohort Study (TMICS)

BACKGROUND

Exposure to either melamine or phthalate, two common toxicants, during pregnancy may cause adverse health effects, including kidney damage.

OBJECTIVES

We investigated the independent and interactive effect of exposure to melamine and phthalates, particularly di-(2-ethylhexyl) phthalate (DEHP), on markers of early renal injury in women their third trimester of pregnancy in one nationwide birth cohort, the Taiwan Maternal and Infant Cohort Study (TMICS).

METHODS

Between October, 2012 and May, 2015, participants were administered questionnaires, physical examinations, and blood and urine tests during their third trimester. One-spot overnight urine specimens were used to simultaneously measure melamine, 11 phthalate metabolites, and two markers of renal injury, microalbumin and N-acetyl-beta-D-glucosaminidas (NAG). Estimated daily DEHP intake was calculated based on measurement of three urinary DEHP metabolites. Microalbuminuria was defined as having a urinary albumin/creatinine ratio (ACR) higher than 3.5 mg/mmol.

RESULTS

Total 1433 pregnant women were analyzed. The median value for urinary melamine was 0.63 μg/mmol Cr and estimated DEHP intake was 1.84 μg/kg/day. We found subjects in the highest quartile of estimated DEHP intake to have significantly higher urinary ACR (β = 0.095, p = 0.043) and the prevalence of microalbuminuria (adjusted OR = 1.752, 95% confidence interval = 1.118-2.746), compared to those in the lowest quartile. In addition, there was a significant interactive effect between urinary melamine and estimated DEHP intake on urinary ACR and NAG.

CONCLUSION

Our results suggest these two ubiquitous chemicals together may be associated with markers of early kidney injury in pregnant women.

Association between Phthalate Exposure and Frailty among Community-Dwelling Older Adults: A Repeated Panel Data Study

Only a few studies have examined the impacts of environmental exposure on frailty. This study investigated the association between phthalates and frailty among community-dwelling older adults. The Korean Elderly Environmental Panel II (KEEP II) study is a repeated panel data study of 800 community-dwelling older adults in South Korea. Frailty was measured with five items defined by Fried and colleagues. Environmental pollutants in the form of two types of metabolites for Di-ethylhexyl phthalate (DEHPs)-Mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and Mono (2-ethyl-5-oxohexyl) phthalate (MEOHP)-were obtained from urine specimens. Analyses were performed using repeated linear mixed models. The concentration levels of both MEOHP and MEHHP in urine were significantly higher in the pre-frail or frail group than its counterparts. While adjusting for covariates, MEOHP level was positively associated with the likelihood of being pre-frail or frail in both males and females; the concentration level of MEHHP also had a positive impact on the likelihood of being pre-frail or frail in females. The DEHP metabolite concentrations were significantly lower among adults with daily fruit consumption in both males and females. DEHPs, measured by metabolite concentrations, may increase the risk of frailty among older men and women; further studies are necessary. The preventive effects of nutrition on DEHP risk should also be further investigated.

New trimester-specific reference intervals for clinical biochemical tests in Taiwanese pregnant women-cohort of TMICS

Background

Because there are no published biochemical reference intervals (RI) for pregnant Taiwanese women, we used an established islandwide birth cohort, the Taiwan Maternal and Infant Cohort Study, to establish RIs for important biochemical parameters in women during their 3rd trimester in Taiwan. Additionally, we compared the differences in these biochemical parameters between early third trimester (weeks 28 to 31) and late third trimester (weeks 37 to 40) of pregnant women as well as the differences in them between the third trimester and after delivery.

Methods

Between 2012 and 2015, we recruited a total of 2,136 pregnant women from nine hospitals located in northern (n = 3), central (n = 3), southern (n = 2), and eastern Taiwan (n = 1) to receive regular prenatal health examinations during their third trimester (weeks 28 to 40). After exclusion, samples obtained from 993 eligible pregnant women were analyzed.

Results

There were increases in both lower and upper normal limits for blood neutrophil, thyroid profile (triiodothyronine (T3) and thyroxine (T4)), testosterone, estradiol, and progesterone and decreases for RBC, hemoglobin (Hb), alanine aminotransferase (ALT) and creatinine (Cr) during their third trimesters. Women in their late third trimester (n = 378) had higher median RBC, Hb, aspartate aminotransferase (AST), Cr, thyroid-stimulating hormone (TSH), testosterone, estradiol, and progesterone and lower median platelet and insulin, compared with those in their early third trimester (n = 490). Twenty-three of the women had both third trimester and post-pregnancy data. After delivery, the women had lower median AST, ALT, insulin, T3, T4, testosterone, estradiol, and progesterone and higher median Cr, free T4, FSH, and luteinizing hormone (LH), compared to their third trimesters.

Conclusions

Gestation-related changes in important biochemical parameters should be considered when evaluating clinical laboratory values in pregnant women.

A benchmark dose study of prenatal exposure to di(2-ethylhexyl) phthalate and behavioral problems in children

INTRODUCTION

Prenatal exposure to di(2-ethylhexyl) phthalate (DEHP) has been reported to be associated with adverse effects on neurodevelopment that yield behavior syndromes in young children with an estimated median exposure lower than the currently recommended tolerable daily intake (TDI) and reference dose (RfD).

OBJECTIVES

Our aim was to derive the benchmark dose for prenatal exposure to DEHP for the neurodevelopmental health in children.

METHODS

A total of 122 mother-child pairs from the Taiwan Maternal and Infant Cohort Study were analyzed for the dose-response relationship between maternal exposure to DEHP and children's behavioral syndromes evaluated at 8 years (n = 122, 2009), 11 years (n = 96, 2012), and 14 years (n = 78, 2015) of age. We employed a multivariate regression model to assess the statistical associations between the estimated maternal average daily intake of DEHP and child's individual CBCL scores for boys and girls at each separate age, followed by a mixed model for all the children across three ages accounting for individual variations. We then employed structural equation models by combining the children's specific behavioral problem scores at different ages and obtained a simulated overall latent score in relation to maternal exposure. Based on the established dose-response relationship, we derived the benchmark dose (BMD) and the lower limit (BMDL).

RESULTS

Associations of maternal DEHP exposure (median 4.54μg/kg_bw/day) with the Child Behavior Checklist (CBCL) scores were all significant, except for somatic complaints, adjusting for child's age, gender, IQ, and family income. The BMDL, given a benchmark response of 0.10 (0.05) and a background response of 0.05, was 6.01 (2.16) μg/kg_bw/dayfor an integrated CBCL score.

CONCLUSIONS

The current TDI (RfD) of 50 (20) μg/kg_bw/day for DEHP might not protect pregnant women for their children from behavioral problems. There remains the lack of comparable toxicological data. Further investigations are needed.

Prenatal and childhood exposure to phthalate diesters and neurobehavioral development in a 15-year follow-up birth cohort study

OBJECTIVE

Longitudinal studies on neurobehavioral development in relation to prenatal and postnatal exposure to phthalates in school-age children and adolescents are limited. We investigated the association of prenatal and childhood phthalate exposure with the development of behavioral syndromes in 8-14-year-old children.

METHOD

We recruited 430 pregnant women from 2000 to 2001 and followed their children at the ages of 2, 5, 8, 11, and 14 years, yielding 153 mother-child pairs in total. Urine samples from pregnant women in the third trimester and from children at 2-8 years of age were analyzed for the concentrations of seven urinary phthalate metabolites: monomethyl phthalate, monoethyl phthalate, monobutyl phthalate, monobenzyl phthalate (MBzP), and three di(2-ethylhexyl) phthalate (DEHP) metabolites, namely mono-2-ethylhexyl phthalate (MEHP), mono(2-ethyl-5-hydroxyhexyl) phthalate, and mono(2-ethyl-5-oxohexyl) phthalate. Behavioral syndromes in children aged 8-14 years were assessed using the Child Behavior Checklist. We constructed mixed models to examine these associations after adjustments for potential covariates.

RESULTS

Maternal urinary MEHP levels were associated with higher scores for internalizing problems (β = 0.028, 95% confidence interval [CI]: 0.0004, 0.055) and externalizing problems (β = 0.040, 95% CI: 0.013, 0.066). Associations of the maternal urinary sum of DEHP metabolite levels with delinquent behavior scores and externalizing problems scores were positive (β = 0.035, 95% CI: 0.013, 0.057 for delinquent behavior; β = 0.026, 95% CI: 0.001, 0.050 for externalizing problems). Furthermore, children's urinary MBzP levels were associated with higher scores for social problems (β = 0.018, 95% CI: 0.001, 0.035). Similar patterns were observed for borderline and clinical ranges.

CONCLUSION

Early-life exposure to phthalates may influence behavioral syndrome development in children. Future studies are needed to replicate these findings, and efforts to reduce exposures to phthalates during critical early life stages may be warranted.