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.

BMI-specific inflammatory response to phthalate exposure in early pregnancy: findings from the TMCHESC study.

Studies that have evaluated associations between phthalate metabolites and inflammation have reported inconsistent results among pregnant women, and it is unclear how body mass index (BMI) affects such relationships. Therefore, the present study aimed to examine the association between urinary phthalate metabolite concentrations and the levels of inflammatory biomarkers in the general circulation among 394 pregnant women selected from the Tianjin Maternal and Child Health Education and Service Cohort (TMCHESC) and to determine the role that BMI plays in the relationship. The concentrations of eight inflammatory biomarkers and three phthalate metabolites were measured in serum and urine samples, respectively. Multivariable linear modeling was conducted to examine the association between each phthalate and inflammatory biomarker while controlling for potential confounding factors in BMI-stratified subgroups. Restricted cubic splines were also utilised to explore potential non-linear relationships. In the high-BMI group, positive associations were observed between the levels of mono-n-butyl phthalate (MBP) and interleukin 1 beta (IL-1ß) (ß = 0.192; 95% CI: 0.033, 0.351), monoethyl phthalate (MEP), and C-reaction protein (CRP) (ß = 0.129; 95% CI 0.024, 0.233), and mono-ethylhexyl phthalate (MEHP) and interleukin 6 (IL-6) (ß = 0.146; 95% CI 0.016, 0.277). Restricted cubic spline models also revealed non-linear associations between the levels of MBP and interleukins 10 and 17A (IL-10 and IL-17A) and between MEP and interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-α) in pregnant women. These results suggest that phthalate exposure plays a potential role in promoting inflammation in the high-BMI group. While the precise mechanisms underlying the proinflammatory effects of phthalates are not fully understood, these findings suggest that BMI may play a role.

Effect of Circadian Distribution of Energy and Macronutrients on Gestational Weight Gain in Chinese Pregnant Women.

Gestational weight gain (GWG) may be affected by the timing of dietary intake. Previous studies have reported contradictory findings, possibly due to inconsistent characterizations of meal timing. We conducted a birth cohort study in Tianjin to determine the effect of daily energy and macronutrient distribution in mid and late pregnancy on GWG. Dietary intake information in the second and third trimesters used three 24-h dietary recalls, and meal timing was defined in relation to sleep/wake timing. The adequacy of GWG was assessed using recommendations from the Institute of Medicine guidelines. Pregnant women who had a relatively high average energy and macronutrient distribution in the late afternoon-early evening time window exhibited a greater GWG rate and a greater total GWG than that in morning time window during the third trimester (ß = 0.707; ß = 0.316). Carbohydrate intake in the morning of the second and third trimesters (ß = 0.005; ß = 0.008) was positively associated with GWG rates. Morning carbohydrate intake in the second trimester was also positively associated with total GWG (ß = 0.004). Fat intake in the morning of the third trimester (ß = 0.051; ß = 0.020) was positively associated with the GWG rates and total GWG. Excessive GWG of Chinese pregnant women was related closely to eating behavior focused on the late afternoon-early evening and carbohydrate and fat intake in the morning during the second and third trimesters.

Associations between prenatal exposure to phthalates and birth weight: A meta-analysis study.

Previous studies have suggested that phthalates are associated with birth weight. However, most phthalate metabolites have not been fully explored. Therefore, we conducted this meta-analysis to assess the relationship between phthalate exposure and birth weight. We identified original studies that measured phthalate exposure and reported its association with infant birth weight in relevant databases. Regression coefficients (ß) with 95% confidence intervals (CIs) were extracted and analyzed for risk estimation. Fixed-effects (I2 ≤ 50%) or random-effects (I2 > 50%) models were adopted according to their heterogeneity. Overall summary estimates indicated negative associations of prenatal exposure to mono-n-butyl phthalate (pooled ß = -11.34 g; 95% CI: -20.98 to -1.70 g) and mono-methyl phthalate (pooled ß = -8.78 g; 95% CI: -16.30 to -1.27 g). No statistical association was found between the other less commonly used phthalate metabolites and birth weight. Subgroup analyses indicated that exposure to mono-n-butyl phthalate was associated with birth weight in females (ß = -10.74 g; 95% CI: -18.70 to -2.79 g). Our findings indicate that phthalate exposure might be a risk factor for low birth weight and that this relationship may be sex specific. More research is needed to promote preventive policies regarding the potential health hazards of phthalates.

Exploring associations between urine levels of phthalates and autism spectrum disorder symptoms: a case-control study in Tianjin, China.

Autism spectrum disorder (ASD) comprises a group of neurodevelopmental disorders. The etiology of autism remains unclear, but a growing body of evidence indicates that phthalates play a role in its pathogenesis. The aim of this study was to compare the urine levels of phthalates in children with ASD and healthy children. We also explored whether phthalates have an effect on ASD symptoms. The participants in this study included 101 children with ASD (79 boys and 22 girls) and 101 sex- and age-matched controls. The levels of phthalates were analyzed by gas chromatography-mass spectrometry (GC-MS). We detected significant differences in monoethyl phthalate (MEP) levels between the severe ASD and control groups (p < 0.05). Mono-n-butyl phthalate (MBP) concentration was positively correlated with language skill impairment in ASD (ß: 0.387, p = 0.041). MEP levels were associated with the CARS "Imitation" score in all children (OR: 1.470). MBP levels were associated with the "Nonverbal Communication" score among boys (OR: 1.233), and MEP levels were associated with the "Nonverbal Communication" score among girls (OR: 2.648). MEP levels were related to the CARS total score after adjustment for sex (ß: 1.524, p = 0.047). Compared with the reference mono(2-ethylhexyl) phthalate (MEHP) group, children with ASD in the medium-exposure group had an OR of 3.370 for aggravating ASD severity. These results suggested that increased exposure to phthalates contributes to more ASD symptoms and that there are potentially sex-specific associations. These findings warrant further confirmation.