Associations of urinary dichloroacetic acid and trichloroacetic acid exposure with platelet indices: Exploring the mediating role of blood pressure in the general population

Associations of exposure to disinfection by-products with blood coagulation parameters among women: Results from the Tongji reproductive and environmental (TREE) study

BACKGROUND

Experimental studies have shown that disinfection byproducts (DBPs) induce coagulotoxicity, but human evidence is scarce.

OBJECTIVE

This study aimed to explore the relationships of DBP exposures with blood coagulation parameters.

METHODS

Among 858 women from the Tongji Reproductive and Environmental (TREE) study, urinary dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were detected as internal biomarkers of DBP exposures. We measured activated partial thromboplastin time (APTT), fibrinogen (Fbg), international normalized ratio (INR), prothrombin time (PT), and thrombin time (TT) as blood coagulation parameters. Multivariable linear regression models were utilized to estimate the relationships between urinary DCAA and TCAA and blood coagulation parameters. The effect modifications by demographic and lifestyle characteristics were further explored.

RESULTS

Elevated tertiles of urinary DCAA concentrations were associated with increased PT and INR (11.29%, 95% CI: 1.66%, 20.92% and 0.99%, 95% CI: 0.08%, 1.90% for the third vs. first tertile, respectively; both P for trends < 0.05). Stratification analysis showed that the positive associations were only observed among younger (< 30 years), leaner (body mass index < 24.0 kg/m2), and non-passive smoking women. Moreover, elevated tertiles of urinary TCAA concentrations in positive associations with PT and INR were observed among younger women (17.89%, 95% CI: 2.50%, 33.29% and 1.82%, 95% CI: 0.34%, 3.30% for the third vs. first tertile, respectively; both P for trends < 0.05) but not among older women (both P for interactions < 0.05).

CONCLUSION

Higher levels of urinary DCAA and TCAA are associated with prolonged clotting time among women.

Association between urinary multiple metals and platelet-related parameters: A cross-sectional study in a metal-contaminated area of China

Previous works have shown that hematological system can be affected by exposure to lead; however, the effects of multiple metals on platelets remain elusive within the population from metal-contaminated areas. Hence, the study enrolled 609 participants, with 396 from a metal-exposed area and 213 from a control area. Platelet count (PLT), mean platelet volume (MPV), thrombocytocrit (PCT), platelet to large cell ratio (P-LCR), and platelet distribution width (PDW) were selected to evaluate platelet function. Stepwise regression and Lasso regression were utilized to identify the most influential metals. Moreover, the generalized linear model (GLM), Bayesian kernel machine regression (BKMR) models, and quantile g-computation were employed to estimate the individual or combined effects associations between 12 urinary metals and platelet indices. The results revealed all metals except vanadium, copper, strontium, and molybdenum were significantly higher in the exposed group. The GLM models indicated that urinary metals, including lead, antimony, and arsenic, exhibited associations with PLT, MPV, P-LCR, and PDW. Quantile g-computation and BKMR demonstrated negative correlations between metal mixtures and MPV as well as PDW. In conclusion, the study highlights the associations between multiple metal exposures and platelet indices, suggesting that elevated levels of the metal mixture may impede platelet activation in the population in metal-contaminated areas.

Associations between Urinary Concentrations of Disinfection Byproducts and in Vitro Fertilization Outcomes: A Prospective Cohort Study in China

BACKGROUND

Experimental studies show that disinfection byproducts (DBPs) can inhibit oocyte maturation, decrease fertilization capacity, and impair embryo development, but human evidence is lacking.

OBJECTIVES

We aimed to evaluate the associations between exposure to drinking water DBPs and in vitro fertilization (IVF) outcomes.

METHODS

The study included 1,048 women undergoing assisted reproductive technology (ART) treatment between December 2018 and January 2020 from a prospective cohort study, the Tongji Reproductive and Environmental study in Wuhan, China. Exposure to DBPs was assessed by dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in up to four urine samples, which were collected on the day of both enrollment and oocyte retrieval. Multivariable generalized linear mixed models, accounting for multiple IVF cycles per woman, were applied to evaluate the associations between urinary biomarkers of DBP exposures and IVF outcomes. Stratified analyses were used to explore the potential effect modifiers.

RESULTS

The included 1,048 women underwent 1,136 IVF cycles, with 960 (91.6%), 84 (8.0%), and 4 (0.4%) women contributing one cycle, two cycles, and three cycles, respectively. We found that elevated quartiles of urinary DCAA and TCAA concentrations were associated with reduced numbers of total oocytes and metaphase II oocytes and that urinary DCAA concentrations with a lower proportion of best-quality embryos (all p for trends < 0.05 ). Moreover, elevated quartiles of urinary DCAA concentrations were associated with decreased proportions of successful implantation, clinical pregnancy, and live birth (14%, 15%, and 15% decreases in adjusted means comparing the extreme quartiles, respectively; all p for trends < 0.05 ). Stratification analyses showed that the inverse associations of urinary TCAA concentrations with multiple IVF outcomes were stronger among women ≥ 30 y of age (p for interactions < 0.05 ).

DISCUSSION

Exposure to drinking water DBPs was inversely associated with some IVF outcomes among women undergoing ART treatment. Further study is necessary to confirm our findings. https://doi.org/10.1289/EHP12447.

Associations of arsenic exposure with blood pressure and platelet indices in pregnant women: A cross-sectional study in Wuhan, China

BACKGROUND

Environmental inorganic arsenic (iAs) exposure is potentially related to abnormal blood pressure (BP) changes and abnormal platelet activation. However, limited epidemiological studies have explored the impacts of iAs exposure on platelet change mediated by BP, especially for pregnant women.

OBJECTIVES

Our purpose was to investigate the associations of arsenic exposure with blood pressure and platelet indices among pregnant women.

METHODS

The present study population included 765 pregnant women drawn from a prospective birth cohort study in Wuhan, China, recruited between October 2013 and April 2016. Urine sampled in the second trimester were used to assess arsenic species concentrations. The relative distribution of urinary arsenic species was used to measure human methylation capacity. BP parameters and platelet indices originated from the medical record. We applied multivariable linear regression models to explore the cross-sectional relationships between urinary arsenic metabolites, BP parameters, and platelet indices. We utilized mediation analysis to investigate the impacts of arsenic exposure on platelet indices through BP as mediator variables.

RESULTS

We observed significant positive correlations between iAs and systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP). Pregnant women with higher methylation capacity to metabolize iAs characterized by higher secondary methylation index (SMI) and total methylation index (TMI) had a more significant reduction in SBP, DBP, and MAP. Pregnant women with higher DBP and MAP had higher platelet counts (PLC). A decreased PLC was found in subjects wither higher SMI. Additionally, SMI was negatively linked to PLC mediated through MAP.

CONCLUSIONS

Obtained results suggested that higher methylation capacity to metabolize iAs might contribute to decreased PLC among pregnant women, and MAP might mediate the influence of SMI on PLC.

Association between gestational arsenic exposure and intrauterine growth restriction: the role of folate content

Gestational arsenic (As) exposure is associated with intrauterine growth restriction (IUGR). This study explored the association among gestational As exposure, IUGR, and reduction of folate content in maternal and umbilical plasma from 530 mother-and-singleton-offspring pairs. Birth weight (BW) was negatively correlated with As in maternal plasma (r=-0.194, P<0.001) and umbilical plasma (r=-0.235, P<0.001). By contrast, a positive correlation was found between BW and maternal folate content (r=0.198, P<0.001). The subjects were divided into As-L and As-H groups. The influence of As-H on small for gestational age (SGA) infants, a marker of IUGR, was evaluated by multivariate logistic regression that excludes interferences of gestational age, infant sex, and other confounding factors. Mothers with As-H had an elevated risk of SGA infants (adjusted OR, 2.370; P<0.05). Interestingly, maternal folate content was lower in subjects with As-H than those with As-L (22.4±10.7 vs 11.2±6.7 nmol/L, P<0.001). Linear correlation models show that As level was negatively correlated with folate content in maternal plasma (r=-0.615, P<0.001) and umbilical plasma (r=-0.209, P<0.001). Moreover, maternal folate reduction has an obvious mediating effect between increased As and decreased BW (β=-0.078, P<0.05). Our results indicate that folate reduction may be a mediator between gestational As exposure and IUGR.

Associations between drinking water disinfection byproducts and menstrual cycle characteristics: A cross-sectional study among women attending an infertility clinic

Disinfection byproducts (DBPs) have been shown to alter ovarian steroidogenesis and cause estrous cyclicity disturbance and prolongation in experimental studies, however human studies are lacking. We aimed to evaluate the cross-sectional associations between drinking water DBPs and menstrual cycle characteristics. A total of 1078 women attending an infertility clinic in Wuhan, China were included between December 2018 and January 2020. Characteristics of menstrual cycle were collected by questionnaires. Concentrations of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were measured in urine as biomarkers of drinking water DBPs. Multivariate logistic and linear regression models were used to evaluate the associations between urinary DCAA and TCAA concentrations and menstrual cycle characteristics. Higher urinary DCAA concentrations were associated with increased odds ratios (ORs) of irregular menstrual cycle (OR = 1.80; 95% CI: 0.97, 3.33 for the highest vs. lowest quartile; P for trend = 0.05) and long menstrual cycle (OR = 1.62; 95% CI: 0.97, 2.70 for the highest vs. lowest quartile; P for trend = 0.06), as well as prolonged variation in cycle length (β = 1.27 days; 95% CI: -0.11, 2.66 for the highest vs. lowest quartile; P for trend = 0.04). Higher urinary TCAA concentrations were associated with prolonged bleeding duration (β = 0.23 days; 95% CI: -0.06, 0.51 for the highest vs. lowest quartile; P for trend = 0.07). These results suggest that exposure to drinking water DBPs is associated with menstrual cycle disturbances. These findings are warranted to confirm in other studies.

Urinary biomarkers of exposure to drinking water disinfection byproducts and ovarian reserve: A cross-sectional study in China

Experimental studies have demonstrated that disinfection byproducts (DBPs) can cause ovarian toxicity including inhibition of antral follicle growth and disruption of steroidogenesis, but there is a paucity of human evidence. We aimed to investigate whether urinary biomarkers of exposure to drinking water DBPs were associated with ovarian reserve. The present study included 956 women attending an infertility clinic in Wuhan, China from December 2018 to January 2020. Antral follicle count (AFC), ovarian volume (OV), anti-Mullerian hormone (AMH), and follicle-stimulating hormone (FSH) were measured as indicators of ovarian reserve. Urinary dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) were assessed as potential biomarkers of drinking water DBP exposures. Multivariate linear and Poisson regression models were applied to estimate the associations of urinary DCAA and TCAA concentrations with indicators of ovarian reserve. Elevated urinary DCAA and TCAA levels were monotonically associated with reduced total AFC (- 5.98%; 95% CI: - 10.30%, - 1.44% in DCAA and - 12.98%; 95% CI: - 17.00%, - 8.76% in TCAA comparing the extreme tertiles; both P for trends ≤ 0.01), and the former was only observed in right AFC but not in left AFC, whereas the latter was estimated for both right and left AFC. Moreover, elevated urinary TCAA levels were monotonically associated with decreased AMH (- 14.09%; 95% CI: - 24.79%, - 1.86% comparing the extreme tertiles; P for trend = 0.03). These negative associations were still observed for the exposure biomarkers modeled as continuous variables. Our findings suggest that exposure to drinking water DBPs may be associated with decreased ovarian reserve.