Repeated measures of prenatal phthalate exposure and maternal hemoglobin concentration trends: The Ma'anshan birth cohort (MABC) study

Placental Transcriptomic Signatures of Prenatal Phthalate Exposure and Identification of Placenta-Brain Genes Associated with the Effects of Phthalate Exposure on Neurodevelopment in Children

Prenatal exposure to phthalates may affect placental function and fetal development, but the underlying mechanisms are unclear. The aim of our study was to explore the alterations in the placental transcriptome associated with prenatal phthalate exposure and to further analyze whether the placental-brain axis (PBA) genes play a mediating role in the association between prenatal phthalate exposure and children's neurodevelopment. We included 172 participants from the Ma'anshan Birth Cohort and collected data on seven phthalate metabolites in urine during pregnancy, placental tissue RNA-seq, and neurodevelopment of offspring. Bioinformatics analysis revealed that aberrant regulation of the placental transcriptome was associated with prenatal phthalate exposure. Exposure to phthalates during pregnancy was found to be associated with neurodevelopmental delay in children aged 6, 18, and 48 months using the multiple linear regression model. Meanwhile, employing mediation analysis, nine PBA genes were identified that mediate the association between exposure to phthalates during pregnancy and the neurodevelopment of children. Our study will provide a basis for potential mechanisms by which prenatal exposure to phthalates affects placental function and children's neurodevelopment.

Association between urinary phthalate metabolites and Anemia in US adults

Initial research indicates a possible connection between exposure to phthalates and the development of anemia. To fill the gap in epidemiological data, our study utilized data from across the United States, representative on a national scale, to evaluate the association between the concentration of phthalate metabolites in urine and both anemia and iron levels. We gathered data on 11,406 individuals from the National Health and Nutrition Examination Survey (NHANES) database, spanning 2003-2018. We conducted logistic and linear regression analyses, adjusted for potential confounding factors, to evaluate the correlations between different phthalate metabolites and anemia, as well as serum iron levels, including gender-stratified analysis. Most urinary phthalate metabolites were positively correlated with an increased risk of anemia, and the majority were negatively correlated with serum iron levels. The study revealed that for every unit increase in ln-transformed metabolite concentrations, the odds ratios (ORs) for anemia increased to varying degrees, depending on the phthalate: Monobutyl phthalate (MBP) at 1.08 (95% CI 1.01-1.17, P = 0.0314), mono(3-carboxypropyl) phthalate (MCPP) at 1.17 (95% CI 1.10-1.24, P < 0.0001), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) at 1.08 (95% CI 1.02-1.15, P = 0.0153), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) at 1.14 (95% CI 1.07-1.21, P < 0.0001), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) at 1.11 (95% CI 1.03-1.18, P = 0.0030), monocarboxynonyl phthalate (MCNP) at 1.11 (95% CI 1.03-1.19, p = 0.0050), and monocarboxyoctyl phthalate (MCOP) at 1.13 (95% CI 1.07-1.19, P < 0.0001). Increased levels of MBP, MEHP, MBzP, MCPP, MEHHP, MEOHP, MIBP, MECPP, MCNP, and MCOP were linked with changes in serum iron levels, ranging from - 0.99 µg/dL (95% CI - 1.69 to - 0.29) to - 3.72 µg/dL (95% CI - 4.32 to - 3.11). Mixed-exposure analysis shows consistency with single-exposure model. Further mediation analysis showed that the association between single urinary phthalates and the risk of anemia was mediated by serum iron with a mediation ratio of 24.34-95.48% (P < 0.05). The presence of phthalate metabolites in urine shows a positive correlation with the prevalence of anemia, which was possibly and partly mediated by iron metabolism. Nonetheless, to confirm a definitive causal link and comprehend the underlying mechanisms of how phthalate exposure influences anemia, additional longitudinal and experimental research is required.

Association of household air pollution exposure and anemia among pregnant women: Analysis of baseline data from 'Household Air Pollution Intervention Network (HAPIN)' trial

BACKGROUND

Anemia is common in low- and middle-income countries (LMICs), causing significant health issues and social burdens. Exposure to household air pollution from using biomass fuels for cooking and heating has been associated with anemia, but the exposure-response association has not been studied.

OBJECTIVES

We evaluated the associations between personal exposure to air pollution and both hemoglobin levels and anemia prevalence among pregnant women in a multi-country randomized controlled trial.

METHODS

We studied 3,163 pregnant women aged 18-35 years with 9-20 weeks of gestation, recruited as part of the Household Air Pollution Intervention Network (HAPIN) randomized controlled trial in Guatemala, India, Peru, and Rwanda. We assessed 24-hour personal exposures to fine particulate matter (PM2.5), black carbon (BC), and carbon monoxide (CO), and measured hemoglobin levels at baseline (15 ± 3 weeks gestation). Linear and logistic regression models were used to examine the associations of measured pollutants with hemoglobin levels and anemia prevalence, adjusting for confounding.

RESULTS

Single-pollutant models showed associations of CO with higher hemoglobin levels and lower anemia prevalence. Bipollutant models involving CO and PM2.5 also revealed that an interquartile range (IQR) increase in CO concentrations (2.26 ppm) was associated with higher hemoglobin levels [β = 0.04; 95 % confidence interval (CI): 0.01, 0.07], and a lower odds of anemia prevalence [odds ratios (OR) = 0.90; 95 % CI: 0.83, 0.98]. PM2.5 was inversely related to hemoglobin and positively associated with anemia, but results were not statistically significant at the 0.05 alpha level. County-specific results showed that 3 of 4 countries showed a similar association between CO and hemoglobin. We found no association of BC levels with hemoglobin levels or with anemia prevalence.

CONCLUSION

Our findings suggest that exposure to CO is associated with higher hemoglobin and lower anemia prevalence among pregnant women, whereas PM2.5 showed the opposite associations.

Trimester-specific effect of maternal co-exposure to organophosphate esters and phthalates on preschooler cognitive development: The moderating role of gestational vitamin D status

Organophosphate esters (OPEs) and phthalate acid esters (PAEs) are prevalent endocrine-disrupting chemicals (EDCs). Humans are often exposed to OPEs and PAEs simultaneously through multiple routes. Given that fetal stage is a critical period for neurodevelopment, it is necessary to know whether gestational co-exposure to OPEs and PAEs affects fetal neurodevelopment. However, accessible epidemiological studies are limited. The present study included 2, 120 pregnant women from the Ma'anshan Birth Cohort (MABC) study. The concentrations of tris (2-chloroethyl) phosphate (TCEP), 6 OPE metabolites and 7 PAE metabolites were measured in the first, second and third trimester using ultra-performance liquid chromatography-tandem mass spectrometry (LC-MS). Cognitive development of preschooler was assessed based on the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition (WPPSI-IV) of the Chinese version. Generalized estimating equations (GEEs), restricted cubic spline (RCS) and generalized additive models (GAMs) were employed to explore the associations between individual OPE exposure and preschooler cognitive development. The quantile-based g-computation (QGC) method was used to estimate the joint effect of PAEs and OPEs exposure on cognitive development. GEEs revealed significant adverse associations between diphenyl phosphate (DPHP) (β: -0.58, 95% CI: -1.14, -0.01), bis (2-butoxyethyl) phosphate(BBOEP) (β: -0.44, 95% CI: -0.85, -0.02), bis(1-chloro-2-propyl) phosphate (BCIPP) (β: -0.81, 95%CI: -1.43, -0.20) and full-scale intelligence quotient (FSIQ) in the first trimester; additionally, TCEP and bis(2-ethylhexyl) phosphate (BEHP) in the second trimester, as well as DPHP in the third trimester, were negatively associated with cognitive development. Through the QGC analyses, mixture exposure in the first trimester was negatively associated with FSIQ scores (β: -1.70, 95% CI: -3.06, -0.34), mono-butyl phthalate (MBP), BCIPP, and DPHP might be the dominant contributors after controlling for other OPEs and PAEs congeners. Additionally, the effect of OPEs and PAEs mixture on cognitive development might be driven by vitamin D deficiency.

Exposure to phthalates and their alternatives in relation to biomarkers of inflammation and oxidative stress in adults: evidence from NHANES 2017-2018

Phthalates and their alternatives are considered significant environmental risk factors that potentially influence inflammation and oxidative stress. However, their impact on biomarkers of inflammation and oxidative stress was inconsistent. This study aimed to explore the associations between phthalates and high-sensitivity C-reactive protein (hsCRP), gamma-glutamyl transferase (GGT), and white blood cell (WBC) counts, employing both univariate exposure and multivariate co-exposure models. For this analysis, a total of 1619 individuals aged 18 years and above, sourced from the National Health and Nutrition Examination Survey (NHANES) conducted between 2017 and 2018, were selected as subjects. We explored the associations between hsCRP, GGT, and WBC counts and eighteen different phthalate metabolites. Multiple linear regression analysis revealed significant associations between both MCNP and MEHP and hsCRP. We observed negative correlations of MCOP, MCPP, MHBP, and MONP with GGT. Conversely, MEHHP and MEHHTP exhibited positive correlations with GGT. Furthermore, MECPTP and MEHHTP showed positive correlations with WBC. Notably, we identified a non-linear relationship between phthalates and inflammation and oxidative stress markers. The Bayesian kernel machine regression (BKMR) analysis demonstrated a negative joint effect of the phthalates mixture on GGT, particularly at lower concentrations. The BKMR model also found that MEOHP and MHiBP were negatively associated with GGT. In contrast, MEHHP showed a significant positive association with GGT. Moderating effect analysis suggested that dietary inflammatory index (DII), income-to-poverty ratio (PIR), age, BMI, and physical activity influenced the association between phthalates and inflammation and oxidative stress. These findings contribute to a deeper understanding of the relationships between phthalates and inflammation and oxidative stress.

Cumulative Exposure to Phthalates and Their Alternatives and Associated Female Reproductive Health: Body Burdens, Adverse Outcomes, and Underlying Mechanisms

The global birth rate has recently shown a decreasing trend, and exposure to environmental pollutants has been identified as a potential factor affecting female reproductive health. Phthalates have been widely used as plasticizers in plastic containers, children's toys, and medical devices, and their ubiquitous presence and endocrine-disrupting potential have already raised particular concerns. Phthalate exposure has been linked to various adverse health outcomes, including reproductive diseases. Given that many phthalates are gradually being banned, a growing number of phthalate alternatives are becoming popular, such as di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH), di(2-ethylhexyl) adipate (DEHA), and di(2-ethylhexyl) terephthalate (DEHTP), and they are beginning to have a wide range of environmental effects. Studies have shown that many phthalate alternatives may disrupt female reproductive function by altering the estrous cycle, causing ovarian follicular atresia, and prolonging the gestational cycle, which raises growing concerns about their potential health risks. Herein, we summarize the effects of phthalates and their common alternatives in different female models, the exposure levels that influence the reproductive system, and the effects on female reproductive impairment, adverse pregnancy outcomes, and offspring development. Additionally, we scrutinize the effects of phthalates and their alternatives on hormone signaling, oxidative stress, and intracellular signaling to explore the underlying mechanisms of action on female reproductive health, because these chemicals may affect reproductive tissues directly or indirectly through endocrine disruption. Given the declining global trends of female reproductive capacity and the potential ability of phthalates and their alternatives to negatively impact female reproductive health, a more comprehensive study is needed to understand their effects on the human body and their underlying mechanisms. These findings may have an important role in improving female reproductive health and in turn decreasing the number of complications during pregnancy.

Urinary phthalate metabolites and anemia: Findings from the Korean National Environmental Health Survey (2015-2017)

BACKGROUND

Several animal studies have suggested an association between phthalate exposure and decreased hemoglobin levels. To address the lack of epidemiological evidence, we evaluated the association between urinary phthalate metabolite concentrations and hematologic indices by using nationally representative data from Korea.

METHODS

Data from 3722 adults included in the third stage (2015-2017) of the Korean National Environmental Health Survey (KONEHS) were used. The association between various urinary phthalate metabolites and hematologic indices (hemoglobin, hematocrit, mean corpuscular volume [MCV], and red blood cell [RBC], white blood cell [WBC], and platelet counts) was evaluated using linear regression analysis adjusted for potential confounders. Sex-stratified analysis was performed.

RESULTS

All urinary phthalate metabolites were negatively associated with hemoglobin levels. A two-fold increase in urinary mono-(2-ethyl-5-carboxy-pentyl) phthalate (MECPP), mono-carboxyoctyl phthalate (MCOP), mono-carboxyonyl phthalate (MCNP), and mono-(3-carboxypropyl) phthalate (MCPP) levels was associated with a -0.099 g/dL (95% confidence interval (CI), -0.137 to -0.060), -0.116 g/dL (95% CI, -0.156 to -0.076), -0.111 g/dL (95% CI, -0.154 to -0.068), and -0.144 g/dL (95% CI, -0.198 to -0.089) change in hemoglobin levels, respectively. The RBC count and MCV showed negative and positive associations, respectively, with urinary phthalate metabolite concentrations. WBC counts were positively associated with MECPP, MCOP, MCNP, and MCPP levels, whereas the platelet count showed no association with urinary phthalate metabolites.

CONCLUSIONS

Urinary phthalate metabolite concentration showed a negative association with hemoglobin level. Since this was a cross-sectional study, further longitudinal and experimental studies are needed to identify a clear causal linkage and the pathological mechanism underlying phthalate exposure and anemia.

Lag associations of gestational phthalate exposure with maternal serum vitamin D levels: Repeated measure analysis

Few studies have investigated the relationships between gestational phthalate exposure and maternal circulating vitamin D. In the Ma'anshan birth cohort, 3265 pregnant women were included. Each woman provided up to three urine and serum samples for measurement of phthalates and 25(OH)D and calcium, respectively. Linear mixed models were performed to analyse the association between phthalate metabolites and 25(OH)D and calcium. Stratified analyses of the relationship between phthalates and 25(OH)D by urine collection season were conducted. Finally, the post hoc lag effect of phthalate exposure on 25(OH)D was determined if longitudinal associations were significant. Some phthalate metabolites were associated with increased 25(OH)D but with decreased calcium. Furthermore, the relationship of phthalate exposure with 25(OH)D varied with urine collection season. Phthalate metabolites collected in summer and autumn were associated with an increase in 25(OH)D, while monobenzyl phthalate collected in winter and spring was inversely associated with 25(OH)D. Finally, high-molecular-weight phthalates had lag associations with 25(OH)D with a 1-trimester lag period. Low-molecular-weight phthalates exhibited lag associations with 25(OH)D with a 2-trimester lag period. In conclusion, the positive cross-sectional correlation between phthalate metabolites and 25(OH)D was partly affected by urine collection season. This study suggested that gestational phthalate exposure would have a lag association with maternal 25(OH)D levels.

Single and mixed effects of prenatal exposure to multiple bisphenols on hemoglobin levels and the risk of anemia in pregnant women

INTRODUCTION

Bisphenols have endocrine-disrupting effects, which may disrupt hemoglobin (Hb) homeostasis and lead to anemia. However, the effects of bisphenols on anemia remain unknown. Therefore, we assessed the effects of single- and multiple-exposure to bisphenols on Hb levels and anemia of pregnant women.

METHODS

The study involved 2035 pregnant women from Guangxi Zhuang Birth Cohort in China. Generalized linear regression, principal component analysis (PCA), quantile g-computation (Qgcomp), and Bayesian kernel machine regression (BKMR) were performed to examine the effects of serum bisphenols on Hb levels and the risk of anemia.

RESULTS

After adjustment, elevated bisphenol A (BPA) levels were correlated with decreased Hb concentrations (β = -0.51; 95%CI: -0.92, -0.10) in the first trimester, and these correlations were more sensitive in mothers of males. Compared with the low-exposure group, bisphenol B (BPB) levels in the high-exposure group led to a 1.52 g/L (95%CI: -3.01, -0.03) decrease in Hb levels in the second trimester; tetrabromobisphenol A (TBBPA) levels in the high-exposure group led to a higher the risk of anemia in the third trimester (OR = 1.46; 95%CI: 1.07, 1.99); bisphenol F (BPF) in the high-exposure group led to lower Hb levels (β = -2.42; 95%CI:-4.69, -0.14) in mothers of male fetuses in the third trimester. Qgcomp showed that elevated levels of bisphenol mixture was correlated with (β = -1.42; 95%CI: -2.61, -0.24) decrease in Hb levels in the second trimester. PCA revealed a negative association between PC2 and Hb levels in the first trimester (β = -0.89; 95%CI: -1.61, -0.17). Similarly, a negative relationship was observed between PC1 and Hb levels in the third trimester among mothers with male fetuses (β = -1.00; 95%CI: -1.94, -0.06).

CONCLUSIONS

Prenatal exposure to single and mixed bisphenols may decrease Hb levels and increase the risk of anemia during pregnancy, the associations may be greater in mothers with male fetuses than those with female fetuses.

Effect of the phthalates exposure on sex steroid hormones in the US population

BACKGROUND

New alternative phthalates have been increasingly substituted for certain phthalates in some consumer products due to safety concerns. However, research on the steroidal effect of exposure to the newer replacement phthalates in the general adult population is lacking.

OBJECTIVES

This study aimed to examine the associations of exposure to the older generation and newer replacement phthalates with sex hormone levels in the U.S. general population.

METHODS

The current cross-sectional study was based on the National Health and Nutrition Examination Survey (NHANES) 2015-2016. Sixteen urinary phthalates metabolites and three serum sex hormones were measured in 1768 adults. Gender-specific associations between urinary phthalate concentrations and sex hormones were estimated by using adjusted multiple linear regression. Logistic regression was performed to calculate the risk of phthalates exposure on hormones dysfunction.

RESULTS

Most phthalates metabolites concentrations were lower than 50 ng/mL. MEP, MBP, MiBP, MECPP, MCOP, MEHHP, MEOHP were higher than others, suggesting that new alternative DEP, DBP, and DiNP were exposed at high levels in daily life while DINCH was at a low level. Phthalates exposure was associated with decreased testosterone levels and increased estradiol and SHBG in total samples. Testosterone level was negatively associated with MnBP (β: -0.05, 95% CI: -0.09, 0), MEOHP (β:-0.05, 95% CI:-0.09,-0.01), MEHHP (β:-0.04, 95% CI:-0.08,0), MECPP (β:-0.07, 95% CI:-0.11,-0.03), MEP (β: -0.03, 95% CI: -0.06, 0), MiBP (β: -0.05, 95% CI: -0.10, -0.01) in males; ln-transformed estradiol were increased by 0.18 pg/mL (95% CI: 0.05,0.31), 0.15 pg/mL (95% CI: 0.01,0.29) with each 1 ln-concentration increase in MEHP and MNP, respectively, in females.

CONCLUSIONS

Our results suggest that phthalates exposure may disturb the hormone homeostasis in adults. The safe alternative should be used with caution in industrial production in the future and the need for further research into the safety of the new alternative replacements is necessary.

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.

Associations between Serum Aflatoxin-B1 and Anemia in Pregnant Women: Evidence from Guangxi Zhuang Birth Cohort in China

Aflatoxin B1 (AFB1) is a common toxic mycotoxin and is detectable in pregnant women. Animal studies have revealed that AFB1 caused the lysis of erythrocytes and a decrease in hemoglobin. We conducted a prospective cohort study in Guangxi, China, in order to evaluate the association between AFB1 exposure and anemia in pregnant women during the entire pregnancy. A total of 616 pregnant women from the Guangxi Zhuang Birth Cohort were included in the study. Serum AFB1-albumin (AFB1-ALB) adduct levels were measured. The effect of AFB1-ALB adducts on hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were analyzed by using multivariable linear regression. The risks of anemia from AFB1-ALB adduct exposure were assessed by multivariable logistic regression. We found that the AFB1-ALB adduct was significantly associated with a decrease in Hb (β = -4.99, 95% CI: -8.42, -1.30), MCV (β = -4.58, 95% CI: -7.23, -1.94), MCH (β = -1.86, 95% CI: -2.87, -0.85), and MCHC (β = -5.23, 95% CI: -8.28, -2.17) in the first trimester with the third tertile of AFB1-ALB adducts when compared with the first tertile. Furthermore, the third tertile of the AFB1-ALB adduct significantly increased the risk of anemia by 2.90 times than compared to the first tertile in the first trimester (OR = 3.90, 95% CI: 1.67, 9.14). A significant positive does-response relationship existed between AFB1-ALB adduct levels and anemia risk (Ptrend = 0.001). When dividing anemia types, we only found that the third tertile of AFB1-ALB adduct increased the risk of microcytic hypochromic anemia (MHA) in the first trimester (OR = 14.37, 95% CI: 3.08, 67.02) and second trimester (OR = 4.75, 95% CI: 1.96, 11.51). These findings demonstrate the correlation between maternal AFB1 exposure during early pregnancy and risk of anemia, especially MHA, and during different trimesters in Southern China. More efforts should be made to diminish AFB1 exposure for pregnant women.

Occupational Exposures to Phthalates among Black and Latina U.S. Hairdressers Serving an Ethnically Diverse Clientele: A Pilot Study

Hairdressers may be differentially exposed to phthalates through hair salon services provided and products used, yet no U.S. studies have investigated these exposures in this population. We characterized concentrations and exposure determinants to nine phthalate metabolites in postshift urine samples among 23 hairdressers from three Black and three Dominican salons, as well as a comparison group of 17 female office workers from the Maryland/Washington D.C. metropolitan area. Overall, hairdressers had higher metabolite concentrations than office workers. The geometric mean (GM) for monoethyl phthalate (MEP) was 10 times higher in hairdressers (161.4 ng/mL) than office workers (15.3 ng/mL). Hairdressers providing select services and using certain products had higher GM MEP concentrations than those who did not: permanent waves/texturizing (200.2 vs 115.4 ng/mL), chemical straightening/relaxing (181.6 vs 92.1 ng/mL), bleaching (182.3 vs 71.6 ng/mL), permanent hair color (171.9 vs 83.2 ng/mL), and Brazilian blowout/keratin treatments (181.4 vs 134.6 ng/mL). Interestingly, hairdressers providing natural services had lower GM MEP concentrations than those who did not: twists (129.1 vs 215.8 ng/mL), sister locs/locs (86.0 vs 241.9 ng/mL), and afros (94.7 vs 203.9 ng/mL). Larger studies are warranted to confirm our findings and identify disparities in occupational phthalate exposures.

Domain- and trimester-specific effect of prenatal phthalate exposure on preschooler cognitive development in the Ma'anshan Birth Cohort (MABC) study

BACKGROUND

Phthalates are a group of heavily produced endocrine disruptors that are widely used in personal care products, food packaging, building materials, and medical device. Few epidemiological studies have examined the effect of repeated prenatal exposure to multiple phthalates on preschooler cognitive development.

OBJECTIVES

This study aimed to examine the association between prenatal phthalate exposure measured at multiple time points and the intelligent quotient (IQ) scores of preschoolers, and to further identify the critical windows and specific intelligence domains in which phthalate exposure would affect preschooler cognitive development.

METHODS

The current study was based on the Ma'anshan Birth Cohort (MABC) study. Seven phthalate metabolites were measured in 2128 maternal urine samples collected during the first, second, and third trimesters of pregnancy. The IQ score of preschool-aged children were assessed with the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence, Fourth edition (WPPSI-Ⅳ CN). Linear mixed models (LMMs) were used to assess the longitudinal effects of repeated prenatal phthalate exposure on children's IQ score. Multiple linear regression models were fitted to determine whether critical window phthalate exposure would affect cognitive development of children.

RESULTS

Overall, the repeated measures analysis indicated that the verbal comprehension index (VCI), visual space index (VSI) and full-scale intelligence quotient (FSIQ) decreased by 0.30 (95% CI: -0.60, 0; p = 0.05), 0.32 (95% CI: -0.62, -0.01; p = 0.04), and 0.31 (95% CI:-0.57, -0.04; p = 0.02) points, respectively, with each ln-transformed increase in the metabolite concentration of MBP. The fluid reasoning index (FRI) and processing speed index (PSI) increased by 0.30 (95% CI: 0.07, 0.54; p = 0.01) and 0.28 (95% CI: 0.06, 0.51; p = 0.01) points, respectively, with each ln-concentration increase in MEP. Trimester-specific regression models stratified by the sample collection time during pregnancy generated consistent results. In the first trimester, each ln-transformed MBP increase was associated with reductions in VCI, VSI and FSIQ of 0.56 (95% CI:-1.09, -0.02; p = 0.04), 0.60 (95% CI:-1.15, -0.05; p = 0.03) and 0.49 (95% CI:-0.97, -0.01; p = 0.04) points, respectively. In the third trimester, we observed that only MBzP exposure was associated with an increase in VCI (β: 0.48, 95% CI: 0.03, 0.92; p = 0.04). The gender-stratified analyses revealed that boys drove these associations.

CONCLUSIONS

Our results suggest that prenatal phthalate exposure impairs the cognitive development of preschoolers. The first trimester of pregnancy might be the most vulnerable period in terms of neurotoxicitydue to phthalate exposure. These findings warrant further confirmation.

Human Erythrocytes Exposed to Phthalates and Their Metabolites Alter Antioxidant Enzyme Activity and Hemoglobin Oxidation

Phthalates used as plasticizers have become a part of human life because of their important role in various industries. Human exposure to these compounds is unavoidable, and therefore their mechanisms of toxicity should be investigated. Due to their structure and function, human erythrocytes are increasingly used as a cell model for testing the in vitro toxicity of various xenobiotics. Therefore, the purpose of our study was to assess the effect of selected phthalates on methemoglobin (metHb), reactive oxygen species (ROS) including hydroxyl radical levels, as well as the activity of antioxidative enzymes, such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), in human erythrocytes. Erythrocytes were incubated with di-n-butyl phthalate (DBP), butylbenzyl phthalate (BBP), and their metabolites, i.e., mono-n-butyl phthalate (MBP) and monobenzyl phthalate (MBzP), at concentrations ranging from 0.5 to 100 µg/mL for 6 or 24 h. This study shows that the analyzed phthalates disturbed the redox balance in human erythrocytes. DBP and BBP, at much lower concentrations than their metabolites, caused a statistically significant increase of metHb and ROS, including hydroxyl radical levels, and changed the activity of antioxidant enzymes. The studied phthalates disturbed the redox balance in human erythrocytes, which may contribute to the accelerated removal of these cells from the circulation.

Associations of grandparental diabetes mellitus with grandchild BMI status

Background

Maternal family history of diabetes was significantly and positively associated with birth weight in grandchildren, we aim to assess the effect of grandparental diabetes on the grandchild’ body mass index (BMI) at infancy peak (IP) and obesity status at age 2.

Methods

In our study, family diabetes mellitus (DM) information from Ma’anshan Birth Cohort Study (MABC) were gathered. For children, height and weight were retrieved from medical records. BMI at 6 observations (0, 3, 6, 9, 12, 18 months) was plotted for every child. Onset of IP was determined by visual inspection. BMI at age 2 was categorized according to WHO Child Growth Standards as normal, overweight or obesity. The association between maternal grandfather’ diabetes and the grandchild’ BMI at IP and BMI at age 2 were tested using linear regression models and logistic regression models, respectively.

Results

In our sample, about 6% of the maternal grandfather had DM, mean of infancy BMI peak was 18.37 kg/m², and 6.6% of the children were obesity at age 2. Maternal grandfather with DM could significantly increase the IP BMI values (β = 0.30, 95 CI = 0.02~0.57), and was associated with obesity status at age 2 (OR = 1.92, 95 CI = 1.08~3.39), but maternal grandmother and paternal grandparents were unrelated.

Conclusion

These results suggest that DM in maternal grandfather may be a risk factor for the grandchild high BMI at peak and obesity at age 2.