Interaction between diet- and exercise-lifestyle and phthalates exposure on sex hormone levels

Unveiling the potential of estrogen: Exploring its role in neuropsychiatric disorders and exercise intervention

Neuropsychiatric disorders shorten human life spans through multiple ways and become major threats to human health. Exercise can regulate the estrogen signaling, which may be involved in depression, Alzheimer's disease (AD) and Parkinson's disease (PD), and other neuropsychiatric disorders as well in their sex differences. In nervous system, estrogen is an important regulator of cell development, synaptic development, and brain connectivity. Therefore, this review aimed to investigate the potential of estrogen system in the exercise intervention of neuropsychiatric disorders to better understand the exercise in neuropsychiatric disorders and its sex specific. Exercise can exert a protective effect in neuropsychiatric disorders through regulating the expression of estrogen and estrogen receptors, which are involved in neuroprotection, neurodevelopment, and neuronal glucose homeostasis. These processes are mediated by the downstream factors of estrogen signaling, including N-myc downstream regulatory gene 2 (Ndrg2), serotonin (5-HT), delta like canonical Notch ligand 1 (DLL1), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), etc. In addition, exercise can act on the estrogen response element (ERE) fragment in the genes of estrogenic downstream factors like β-amyloid precursor protein cleavase 1 (BACE1). However, there are few studies on the relationship between exercise, the estrogen signaling pathway, and neuropsychiatric disorders. Hence, we review how the estrogen signaling mediates the mechanism of exercise intervention in neuropsychiatric disorders. We aim to provide a theoretical perspective for neuropsychiatric disorders affecting female health and provide theoretical support for the design of exercise prescriptions.

Persistent high exposure to exogenous phthalates and endogenous sex hormones associated with early pubertal onset among children: A 3.5-year longitudinal cohort study in China

BACKGROUND

Early onset of puberty could have significant impacts on childhood health, but the extent to which it was affected by phthalate esters (PAEs) and sex hormone disruption was not understood. The aim of this study is to investigate the associations between exposure to PAEs and sex hormone disruption and early onset of puberty in children.

METHODS

A longitudinal cohort study was conducted in China from May 2017 to Oct 2020, involving 740 children during consecutive visits. The onset of puberty was evaluated using Tanner definition, and early puberty was defined as an onset age less than the first 25 %, with cut-offs of 10.33 and 8.97 years for boys and girls, respectively. Serum testosterone (TT), estradiol (E₂) and urinary PAE metabolites were measured during three visits. Generalized linear models were used to explore the associations between PAE and sex hormones with the age of puberty onset, while log-binomial regressions were applied to assess the associations of persistent exposure to PAEs and sex hormones with early pubertal onset.

RESULTS

Approximately 86.0 % of boys and 90.2 % of girls completed puberty onset from pre-puberty, and more than 95 % of participants had PAE concentrations higher than the limit of detection. Boys showed higher exposure to PAE pollutants and higher TT levels. Persistent exposure to PAEs was positively associated with early pubertal onset in girls (ARR = 1.97, 95 %CI = 1.12, 3.46). Moreover, persistent exposure to PAEs and E₂ had synergistic associations with early pubertal onset in both boys (ARR = 4.77, 95 %CI = 1.06, 21.54) and girls (ARR = 7.07, 95 %CI = 1.51, 33.10). However, PAEs and TT had antagonistic associations only in boys (ARR = 0.44, 95 %CI = 0.07, 2.58).

CONCLUSION

Long-term exposure to PAEs might increase the risk of early pubertal onset, and it appears to work in synergy with E₂, while in antagonism with TT in boys' early pubertal onset. Reducing PAEs exposure might promote pubertal health.

The effect of phthalates exposure during pregnancy on asthma in infants aged 0 to 36 months: a birth cohort study

This cohort study sought to investigate the effects of phthalates exposure during pregnancy on offspring asthma and its association with placental stress and inflammatory factor mRNA expression levels. A total of 3474 pregnant women from the China Ma'anshan birth cohort participated in this study. Seven phthalate metabolites were detected in urine samples during pregnancy by solid phase extraction-high-performance liquid chromatography tandem mass spectrometry. Placenta stress and inflammation mRNA expression were assessed by real-time quantitative polymerase chain reaction (RT-qPCR). Early pregnancy may be the critical period when phthalates exposure increases the risk of asthma in infants and young children, and there is a certain gender difference in the risk of asthma in infants and young children. Moreover, through the placenta stress and inflammatory factor associated with infant asthma found anti-inflammatory factor of interleukin-10 (IL-10) mRNA expression will reduce the risk of 36-month-old male infant asthma. The expression of interleukin-4(IL-4) and macrophage (M2) biomarker cluster of differentiation 206(CD206) mRNA reduced the risk of asthma in 18-month-old female infants. Placental stress and inflammatory response were analyzed using mediating effects. Tumor necrosis factor-α (TNFα) showed a complete mediating effect between mono-benzyl phthalate (MBzP) exposure in early pregnancy and asthma in 12-month-old males, and IL-10 also showed a complete mediating effect between mono-n-butyl phthalate (MBP) exposure in early and late pregnancy and asthma in 36-month-old males. In summary, exposure to phthalates during pregnancy may contribute to the development of asthma in infants, which may be associated with placental stress and inflammation.

Degradation of dimethyl phthalate through Fe(II)/peroxymonosulphate heightened by fulvic acid: efficiency and possible mechanism

Ferrous iron (Fe(II)) reacts with peroxymonosulphate (PMS) to form active oxidants that can degrade refractory organic pollutants. However, the conversion rate of Fe(III) to Fe(II) is slow, which limits its actual application. In the study, the effect of fulvic acid (FA) on the degradation of dimethyl phthalate (DMP) by Fe(II)/PMS was investigated. Moreover, the degradation process of DMP was predicted by the preliminary identification of active free radicals and intermediates. As expected, FA gave rise to a higher concentration of Fe(II) than that in Fe(II)/PMS to enhance the removal of DMP in Fe(II)/PMS system. The precipitate, involved in FA and iron, was an important composite to promote the degradation of DMP in the system. Also, the response surface methodology (RSM) was applied to model and optimize the degradation conditions of DMP. The highest removal efficiency (85.70%) was obtained at pH = 3.86, [PMS] = 0.96 mM, [FA] = 11.44 mg/L and [DMP] = 5 µM. The results of free radical quenching experiments and EPR showed that •OH and SO₄^•- were the main active radicals in this system. The degradation intermediates of DMP were monomethyl phthalate (MMP), phthalic acid and benzoic acid. Discoveries of this study had raised the current understanding of the application of FA keeping the cycles of Fe(II)/Fe(III) for peroxymonosulphate activation, which could afford valuable information for the degradation of organic pollutants by FA/Fe(II)/PMS.

Mixed exposure to phthalates and organic UV filters affects Children's pubertal development in a gender-specific manner

BACKGROUND

Previous studies showed phthalates and UV filters are endocrine-disruptive and associated with puberty. However, few studies have examined effects of mixed exposure.

METHODS

Six phthalate metabolites and 12 organic UV filters were detected among 223 school-age children. Puberty development was evaluated at baseline and after 18 months of follow-up. Ordered logistic regression models, least absolute shrinkage and selection operator (LASSO) regression and quantile-based g-computation (qgcomp) were used to evaluate relationships between phthalate metabolites or UV filters exposure and pubertal development.

RESULTS

Six phthalate metabolites and 5 UV filters were detectable in urine samples. In boys, BP-3 and 4'-MAP were negatively associated with genital (ORBP-3 = 0.52, (0.27, 0.93), OR4'-MAP = 0.45, (0.25, 0.74)) and pubic hair development (ORBP-3:0.24, (0.05, 0.76), OR4'-MAP:0.24, (0.05, 0.77)). In girls, MEP levels were associated with advanced breast development (OR: 1.29, (1.04, 1.64)). LASSO regression identified BP-3, 4'-MAP, and OD-PABA for inverse associations with pubertal development in boys. MEP was related to an increase in girls' breast development (OR: 1.64, (1.08, 2.63)). Overall mixture was related to a 70% reduction in boys' genital development stage, with a larger effect size than a single chemical in qgcomp. Mixed exposure was associated with girls' earlier puberty onset (OR: 2.61, (1.06, 6.42)).

CONCLUSIONS

Our results suggested higher levels of phthalate metabolites and UV filters were associated with delayed pubertal development in boys but with earlier puberty in girls. Higher effect size of joint exposure than single chemicals suggested phthalates and UV filters might have synergistic effects on puberty and distort adolescent endocrine function together.

Effect of triclosan exposure on ovarian hormones, trace elements and growth in female rats

Triclosan (TCS) is an antibacterial compound used mainly in personal care products. Its widespread use for decades has made it one of the most widely detected compounds in environmental matrices and in biological fluids. Although it has been shown to be an endocrine disruptor in rats and aquatic species, its safe use by humans is unclear. The aim of the present study was to evaluate the effects of exposure to TCS in female rats. To this end, 14 rats were divided into two groups and fed daily as follows: the control group with sesame oil and the TCS group at a dose of 50 mg/kg/day for 28 days. Any signs of toxicity in the rats were observed daily, and the weight and phase of the estrous cycle were recorded. At the end, the rats were decapitated, the serum and ovaries were collected. The levels of testosterone and progesterone in serum were determined by immunoassay and mass spectrometry. Estradiol (in serum) and kisspeptin-10 (in serum and ovary) were measured only by immunoassays. Trace elements were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The weight gain study of the rats showed a significant decrease by exposure to TCS, while the estrous cycle was not significantly affected compared to the control. The optimized methods based on mass spectrometry showed a significant decrease in the levels of progesterone and testosterone due to exposure to TCS. In addition, elements determined by ICP-MS in rat serum showed significant changes in calcium, lithium and aluminum due to TCS treatment. Finally, the kisspeptin-10 levels did not show a negative effect due to the treatment by TCS. The results suggest that medium-term exposure to TCS did not significantly alter estrous cyclicity but caused alterations in growth, sex hormone levels and some elements in the rat serum.

The Joint Effect of Perceived Psychosocial Stress and Phthalate Exposure on Hormonal Concentrations during the Early Stage of Pregnancy: A Cross-Sectional Study

Phthalates alter the hormonal balance in humans during pregnancy, potentially affecting embryonic and fetal development. We studied the joint effect of exposure to phthalates, quantified by urinary phthalate metabolite concentration, and perceived psychological stress on the concentration of hormones in pregnant women (n = 90) from the Nitra region, Slovakia, up to the 15th week of pregnancy. We used high-performance liquid chromatography, tandem mass spectrometry (HPLC-MS/MS), and electro-chemiluminescence immunoassay to determine urinary concentrations of phthalates and serum concentrations of hormones, respectively. We used Cohen perceived stress scale (PSS) to evaluate the human perception of stressful situations. Our results showed that mono(carboxy-methyl-heptyl) phthalate (cx-MiNP) and a molar sum of di-iso-nonyl phthalate metabolites (ΣDiNP) were negatively associated with luteinizing hormone (LH) (p ≤ 0.05). Mono(hydroxy-methyl-octyl) phthalate (OH-MiNP) and the molar sum of high-molecular-weight phthalate metabolites (ΣHMWP) were positively associated with estradiol (p ≤ 0.05). PSS score was not significantly associated with hormonal concentrations. When the interaction effects of PSS score and monoethyl phthalate (MEP), cx-MiNP, ΣDiNP, and ΣHMWP on LH were analyzed, the associations were positive (p ≤ 0.05). Our cross-sectional study highlights that joint psychosocial stress and xenobiotic-induced stress caused by phthalates are associated with modulated concentrations of reproductive hormones in pregnant women.

Exposure to phthalates in early pregnancy and the risk of fetal growth restriction: a nested case-control study in a Zhuang Chinese population

Phthalates (PAEs) are common endocrine disrupting chemicals (EDCs) that disrupt fetal development. The present study aimed to evaluate the effects of single and coexposure to phthalates in early pregnancy on fetal growth restriction (FGR) by a nested case-control study based on the Guangxi Zhuang Birth Cohort (GZBC). Maternal serum concentrations of seven phthalates in 97 neonates with FGR and 291 matched controls were detected through gas chromatography-mass spectrometry (GC-MS). The associations between phthalates and FGR were analyzed using multiple logistic regression, weight quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models. We found that exposures to butyl-benzyl phthalate (BBP, OR_adj = 1.849, 95% CI: 1.080-3.177, P_adj = 0.025, P_trend = 0.046), di (2-ethyl-hexyl) phthalate (DEHP, OR_adj = 3.893, 95% CI: 1.305-11.910, P_adj = 0.015, P_trend = 0.098) and dimethyl phthalate (DMP, OR_adj = 1.722, 95% CI: 1.089-2.725, P_adj = 0.020, P_trend = 0.002) were significantly positively associated with the risk of FGR, while mono-butyl phthalate (MBP) showed a significant negative association with FGR (OR_high = 0.192, 95% CI: 0.036-0.795, P_adj = 0.033, P_trend = 0.035) only among girls. The WQS model identified that BBP, di(2-ethyl)phthalate (DEP), DMP, DEHP, di-n-butyl phthalate (DBP), and MBP were highly weighted in the association with FGR. The BKMR model supported the positive association between joint exposure to phthalates and the risk of FGR and identified no significant interaction between the seven phthalates. Overall, maternal exposure to BBP, DEHP, and DMP may cause adverse effects on FGR, especially with combined effects.

Exposure to disinfection by-products and reproductive hormones among women: Results from the Tongji Reproductive and Environmental (TREE) study

BACKGROUND

Disinfection by-products (DBPs) have been shown to impair female reproductive function. However, epidemiological evidence on reproductive hormones is scarce.

OBJECTIVE

To investigate the associations between DBP exposures and reproductive hormones among women undergoing assisted reproductive technology.

METHODS

We included 725 women from the Tongji Reproductive and Environmental (TREE) Study, an ongoing cohort conducted in Wuhan, China during December 2018 and January 2020. Urine samples collected at recruitment were quantified for dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) as biomarkers of DBP exposures. At day 2-5 of menstruation, serum reproductive hormones including luteinizing hormone (LH), estradiol (E₂), total testosterone (T), progesterone (PRGE), and prolactin (PRL) were determined. Multivariate linear regression models were performed to assess the associations of urinary DCAA and TCAA concentrations with reproductive hormone levels. Dose-response relationships were investigated using natural cubic spline (NCS) and restricted cubic spline (RCS) models.

RESULTS

After adjusting for relevant confounders, we observed that higher urinary DCAA levels were associated with increased serum PRGE (9.2%; 95% CI: -0.55%, 19.8% for the highest vs. lowest tertile; P for trend = 0.06). Based on NCS models, we observed U-shaped associations of urinary DCAA with serum PRGE and PRL; each ln-unit increment in urinary DCAA concentrations above 3.61 μg/L and 6.30 μg/L was associated with 18.9% (95% CI: 4.8%, 34.7%) and 23.3% (95% CI: -0.92%, 53.5%) increase in serum PRGE and PRL, respectively. The U-shaped associations were further confirmed in RCS models (P for overall association ≤0.01 and P for non-linear associations ≤0.04). We did not observe evidence of associations between urinary TCAA and reproductive hormones.

CONCLUSION

Urinary DCAA but not TCAA was associated with altered serum PRGE and PRL levels among women undergoing assisted reproductive technology.

Does healthy lifestyle attenuate the detrimental effects of urinary polycyclic aromatic hydrocarbons on phenotypic aging? An analysis from NHANES 2001-2010

Existing evidence has showed that exposure to polycyclic aromatic hydrocarbons (PAHs) increases the risk of many chronic diseases. Given the close connection between aging (a major risk factor) and chronic diseases, however, very few studies have evaluated the association between PAHs and aging. Furthermore, whether modifiable healthy lifestyle could attenuate the detrimental effect of PAHs on aging remains unknown. Therefore, we conducted this study, aiming to: (1) examine the associations of urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and lifestyle with Phenotypic Age Acceleration (PhenoAge.Accel), a novel aging measure that captures morbidity and mortality risk; and (2) evaluate the potential interaction effects of OH-PAHs and lifestyle on PhenoAge.Accel. Cross-sectional data of 2,579 participants (aged 20-84 years, n = 1,292 females) from the National Health and Nutrition Examination Survey for years 2001-2010 were analyzed. A lifestyle index was constructed based on five components (drinking, smoking, body mass index, physical activity, and diet), ranging from 0 to 5. We calculated PhenoAge.Accel using algorithms developed previously. General linear regression models were used to examine the associations. We observed strong associations of OH-PAHs and lifestyle with PhenoAge.Accel. For instance, one unit increase in ∑NAP (sum of 1- and 2-hydroxynaphthalene) was associated with 0.37 year (95% confidence interval [CI]: 0.26, 0.48) increase in PhenoAge.Accel. We did not observe statistically significant interaction effects between OH-PAHs and lifestyle on PhenoAge.Accel. After stratified by sex, we observed strong associations as well as statistically significant interactions of OH-PAHs and lifestyle with PhenoAge.Accel among females. In conclusion, both OH-PAHs and lifestyle were independently associated with phenotypic aging and there were statistically significant interactions between OH-PAHs and lifestyle on phenotypic aging among females. The findings highlight the importance of adherence to a healthy lifestyle to attenuate the detrimental effects of exposures to PAHs on phenotypic aging among females.

Urinary phthalate metabolite concentrations and serum hormone levels in pre- and perimenopausal women from the Midlife Women's Health Study

BACKGROUND

Phthalate exposure is associated with altered reproductive function, but little is known about associations between phthalate and hormone levels in midlife women.

METHODS

This cross-sectional analysis includes 45-54-year-old pre- and perimenopausal women from Baltimore, MD and its surrounding counties enrolled in the Midlife Women's Health Study (n = 718). Serum and urine samples were collected from participants once a week for four consecutive weeks to span the menstrual cycle. Serum samples were assayed for estradiol, testosterone, progesterone, sex hormone binding globulin (SHBG), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH), and geometric means were calculated for each hormone across all four weeks. Urine samples were analyzed for nine phthalate metabolites from pools of one-to-four urine samples. Phthalate metabolite concentrations were specific gravity-adjusted and assessed as individual metabolites or as molar sums of metabolites from common parents (di(2-ethylhexyl) phthalate metabolites, ∑DEHP), exposure sources (plastic, ∑Plastics; personal care products, ∑PCP), biological activity (anti-androgenic, ∑AA), and sum of all metabolites (∑Phthalates). We used linear regression models to assess overall associations of phthalate metabolites with hormones, controlling for important demographic, lifestyle, and health factors. We also explored whether associations differed by menopause status, body mass index (BMI), and race/ethnicity.

RESULTS

Most participants were non-Hispanic white (67%) or black (29%), college-educated (65%), employed (80%), and had somewhat higher mean urinary phthalate metabolite concentrations than other U.S. women. Overall, the following positive associations were observed between phthalate metabolites and hormones: ∑DEHP (%Δ: 4.9; 95%CI: 0.5, 9.6), ∑Plastics (%Δ: 5.1; 95%CI: 0.3, 10.0), and ∑AA (%Δ: 7.8; 95%CI: 2.3, 13.6) with estradiol; MiBP (%Δ: 6.6; 95%CI: 1.5, 12.1) with testosterone; ∑DEHP (%Δ: 8.3; 95%CI: 1.5, 15.6), ∑Plastics (%Δ: 9.8; 95%CI: 2.4, 17.7), MEP (%Δ: 4.6; 95%CI: 0.1, 9.2), ∑PCP (%Δ: 6.0; 95%CI: 0.2, 12.2), ∑Phthalates (%Δ: 9.0; 95%CI: 2.1, 16.5), and ∑AA (%Δ: 12.9; 95%CI: 4.4, 22.1) with progesterone; and MBP (%Δ: 8.5; 95%CI: 1.2, 16.3) and ∑AA (%Δ: 9.0; 95%CI: 1.3, 17.4) with AMH. Associations of phthalate metabolites with hormones differed by menopause status (strongest in premenopausal women for estradiol, progesterone, and FSH), BMI (strongest in obese women for progesterone), and race/ethnicity (strongest in non-Hispanic white women for estradiol and AMH).

CONCLUSIONS

We found that phthalate metabolites were positively associated with several hormones in midlife women, and that some demographic and lifestyle characteristics modified these associations. Future longitudinal studies are needed to corroborate these findings in more diverse midlife populations.

Long-term exposure to particulate matter and residential greenness in relation to androgen and progesterone levels among rural Chinese adults

BACKGROUND

Population-based studies on the associations of long-term exposure to particulate matter (PM) with androgen and progesterone are still scant. Residential greenness is benefits health by promoting physical activity, reducing air pollution, and improving mental health, but it remains unclear whether it is related to androgen and progesterone levels among humans.

AIMS

This study aimed to explore the individual and interactive effects of PM and residential greenness on serum testosterone and progesterone levels among rural Chinese adults.

METHODS

A total of 6017 subjects were recruited from the baseline of the Henan Rural Cohort Study in 2016. Serum testosterone and progesterone were measured with liquid chromatography-tandem mass spectrometry. Particulate matters (PM) (PM₁, PM_2.5, and PM₁₀) were assessed by machine learning algorithms. Residential greenness was assessed using the normalized difference vegetation index (NDVI) within 500-m, 1000-m, and 3000-m buffers around participants' residences. The effects of air pollutants and residential greenness and their interaction on serum testosterone and progesterone levels were assessed using linear mixed-effects models with township as a random intercept.

RESULTS

After adjusting for potential confounding factors, a 1 μg/m³ increase in PM_2.5 or PM₁₀ was associated with a 0.037 or 0.030 ng/ml increase in serum testosterone, respectively, in females and with a 0.111 or 0.182 ng/ml decrease in serum progesterone, respectively, in males. A 1 μg/m³ increase in PM₁, PM_2.5 or PM₁₀ was associated with a 0.222, 0.306, or 0.295 ng/ml decrease in serum progesterone, respectively, among females. Moreover, a 0.1-unit increase in NDVI was associated with a 0.310 ng/ml increase in serum testosterone and a 0.170 ng/ml increased in serum progesterone in males, as well as with a 0.143 ng/ml increase in serum progesterone in females. Interaction effects of PM and residential greenness on serum testosterone and progesterone levels were observed, indicating that the effects of residential greenness on serum testosterone and progesterone were modified by high levels of PM. In addition, physical activity significantly mediated 2.92% of the estimated association between greenness and testosterone levels.

CONCLUSIONS

Our study suggested that long-term exposure to PM was positively associated with serum testosterone in males but negatively associated with progesterone levels in both genderssin. In addition, positive associations of residential greenness with serum testosterone and progesterone levels were observed, but they were modified by high levels of PM. Furthermore, the estimated effects of residential greenness on testosterone levels were partly mediated by physical activity.

Interaction between testosterone and obesity on hypertension: A population-based cross-sectional study

BACKGROUND AND AIMS

We aimed to evaluate the effects of serum testosterone, obesity and their interaction on blood pressure (BP) parameters and hypertension among Chinese rural adults.

METHODS

A total of 6199 adults were recruited from the Henan Rural Cohort Study. Serum testosterone was measured by liquid chromatography-tandem mass spectrometry. Logistic regression and linear regression were used to evaluate the association between testosterone, hypertension and BP parameters (including systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP)). A generalized linear model was performed to identify the interactive effects of testosterone and obesity on hypertension.

RESULTS

High levels of serum testosterone were associated with a lower prevalence of hypertension in males (odds ratio (OR): 0.69, 95% confidence interval (CI): 0.53, 0.89). After stratification by obesity, observed associations were only found in non-obese males. Each one-unit increase in ln-testosterone was associated with a 1.23 mmHg decrease in SBP, 0.97 mmHg decrease in DBP, and 1.05 mmHg decrease in MAP among males. Moreover, interactive effects between testosterone and obesity on hypertension and BP parameters were found, indicating that protective effects of serum testosterone on hypertension and BP parameters were counteracted and accompanied by increased values of obesity-related indicators in males, and additional testosterone increased BP parameters and prevalence of hypertension at high levels of waist-to-hip ratio and waist-to-height ratio in females.

CONCLUSIONS

Elevated levels of serum testosterone were associated with decreased BP parameters and prevalent hypertension in males, and obesity modifying effects of serum testosterone on BP parameters and hypertension.

Praegnatio Perturbatio-Impact of Endocrine-Disrupting Chemicals

The burden of adverse pregnancy outcomes such as preterm birth and low birth weight is considerable across the world. Several risk factors for adverse pregnancy outcomes have been identified. One risk factor for adverse pregnancy outcomes receiving considerable attention in recent years is gestational exposure to endocrine-disrupting chemicals (EDCs). Humans are exposed to a multitude of environmental chemicals with known endocrine-disrupting properties, and evidence suggests exposure to these EDCs have the potential to disrupt the maternal-fetal environment culminating in adverse pregnancy and birth outcomes. This review addresses the impact of maternal and fetal exposure to environmental EDCs of natural and man-made chemicals in disrupting the maternal-fetal milieu in human leading to adverse pregnancy and birth outcomes-a risk factor for adult-onset noncommunicable diseases, the role lifestyle and environmental factors play in mitigating or amplifying the effects of EDCs, the underlying mechanisms and mediators involved, and the research directions on which to focus future investigations to help alleviate the adverse effects of EDC exposure.

Impact of gestational exposure to endocrine disrupting chemicals on pregnancy and birth outcomes

With the advent of industrialization, humans are exposed to a wide range of environmental chemicals, many with endocrine disrupting potential. As successful maintenance of pregnancy and fetal development are under tight hormonal control, the gestational exposure to environmental endocrine disrupting chemicals (EDC) have the potential to adversely affect the maternal milieu and support to the fetus, fetal developmental trajectory and birth outcomes. This chapter summarizes the impact of exposure to EDCs both individually and as mixtures during pregnancy, the immediate and long-term consequences of such exposures on the mother and fetus, the direct and indirect mechanisms through which they elicit their effects, factors that modify their action, and the research directions to focus future investigations.

Joint effect of polycyclic aromatic hydrocarbons and phthalates exposure on telomere length and lung function

Exposure to polycyclic aromatic hydrocarbons and phthalates are linked to lung function decline and altered relative telomere length (RTL) accompanying with oxidative stress and inflammatory events in human body. However, limited data are available about impacts of co-exposure of PAHs and phthalates on lung function and RTL. We conducted a pilot study with repeated measures during the winter of 2014 and summer of 2015 in Wuhan city, China. Participants took part in the measures of lung function, RTL, urinary monohydroxylated-PAHs (OH-PAHs) and phthalate metabolites over three consecutive days in each season. Linear mixed-effect (LME) models and Bayesian kernel machine regression (BKMR) were used to analyze the relations of OH-PAHs or phthalate metabolites with lung function or RTL. LME models showed the negative associations of 3-day average of hydroxyphenanthrene (2 + 3-, 4-OHPhe) or 1-hydroxypyrene with FEV1, 3-day average of 2 + 3-OHPhe with FVC. BKMR models revealed the negative relation of eight OH-PAHs with FEV1, FVC or RTL; nine phthalate metabolites may counteract an overall effect of eight OH-PAHs on FEV1, FVC or RTL. The findings indicated that urinary phthalate metabolites may counteract the negative association of urinary OH-PAHs on FEV1 or FVC, which may be partially linked to shorter RTL regarding biological aging.

Effect of exposure to phthalates on association of polycyclic aromatic hydrocarbons with 8-hydroxy-2'-deoxyguanosine

BACKGROUND

Although polycyclic aromatic hydrocarbons (PAHs) and phthalates separately related to oxidative DNA damage have been reported, the joint effect of them on oxidative DNA damage need to be evaluated.

METHODS

In this pilot study, 106 participants were recruited from the community-dwelling residents (n=1240) of Wuhan city, China. Each individual provided three continuous days of spot urine samples for measuring the urinary monohydroxylated PAHs (OH-PAHs), phthalates metabolites and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in the two seasons. Linear mixed effect model and Bayesian Kernel Machine Regression (BKMR) were used to analyze joint effect of urinary PAHs and phthalates metabolites on urinary 8-OHdG levels. We measured cellular and mitochondrial reactive oxygen species (ROS), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) levels as well as IL-6 and IL-8 secretions by the corresponding commercial kits in HepG2 cells treated with di (2-ethylhexyl) phthalate (DEHP, 62.5, 125.00, 250.00, 500.00 or 1000.00μM) alone, benzo[a]pyrene (BaP, 50.00μM) alone or both DEHP and BaP.

RESULTS

Linear mixed effect model showed that each of urinary PAHs metabolite was positively associated with urinary 8-OHdG levels; urinary level of mono (2-ethylhexyl) phthalate or monoisononyl phthalate was positively associated with urinary 8-OHdG levels; BKMR model indicated that a positive association of eight OH-PAHs with urinary 8-OHdG levels, nine urinary phthalates metabolites enhanced the association. We found that DEHP at the indicated concentration plus 50.00μM BaP increased cellular and mitochondrial ROS levels, IL-6 and IL-8 secretions at 24 and 48h as well as MDA levels and GSH-Px activities at 48h, compared to the solvent control.

CONCLUSIONS

Exposure to certain dose phthalates may attenuate the positive association of PAHs exposure with oxidative DNA damage in the body. DEHP at the certain concentrations enhanced BaP-induced mitochondrial ROS, pro-inflammatory response and the activation of the antioxidant defense system in HepG2 cells.