Single-chemical and mixture effects of multiple volatile organic compounds exposure on liver injury and risk of non-alcoholic fatty liver disease in a representative general adult population

Individual and mixture effects of BTEX occupational exposure with hematologic and hepatic profiles in petrochemical workers and the metabolic mechanism

Evidence on the association of occupational exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) with hematologic and hepatic profiles were equivocal, and few studies have investigated overall effect of BTEX mixtures. Herein, significant higher concentrations (p < 0.05) of hippuric acid, 1,2-dihydroxybenzene, mandelic acid, trans, trans-muconic acid and phenylglyoxylic acid were found in petrochemical workers than the controls, in accordance with higher levels of hematologic and hepatic profiles found in petrochemical workers (p < 0.05). Occupational exposure to individual BTEX was associated with elevated levels of white blood cell (WBC), lymphocyte (LYMPH), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). Further, the Weighted Quantile Sum Regression model and Bayesian Kernel Machine Regression model consistently identified a positive association between BTEX mixture exposure and WBC, LYMPH, and GGT. Xylene was the primary contributor to increased WBC, LYMPH, and GGT levels. Furthermore, BTEX exposure resulting in the increased inflammation indices were mainly related to perturbations of sphingolipid metabolism, biosynthesis of unsaturated fatty acids, and primary bile acid biosynthesis. Whereas metabolites mediated the correlation between BTEX exposure and liver function indices were related to the perturbations of biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, sphingolipid metabolism, primary bile acid biosynthesis, etc. Our findings revealed potential health risk of occupational exposure to BTEX and might help one to understand the link between BTEX exposure and hematologic and hepatic profiles.

Key role of extracellular vesicles in the induction of necroptosis and apoptosis by a mixture of polycyclic aromatic hydrocarbons in the context of a steatohepatitis-like state

A positive association between human exposure to environmental pollutants and progression from benign hepatic steatosis to advanced chronic liver diseases has been documented. Among chemicals found in air pollution, polycyclic aromatic hydrocarbons (PAHs) are of particular concern, due to their omnipresence in the environment. Ingestion of contaminated food is the primary route of exposure. Previous studies on the ability of PAHs to induce the pathological progression of liver steatosis have been limited to the analysis of individual PAHs. The aim of this study was therefore to examine the effects of a mixture of PAHs whose composition closely recapitulates that of contaminated food. The PAH mixture elicited both a steatohepatitis-like state in steatotic WIF-B9 hepatocytes (100 nM for 72 hours) and the progression of steatohepatitis in rats fed a lipid-enriched diet (0.8 mg/kg for 90 days). The PAH mixture induced transient necroptosis at 5 hours followed by a gradual increase in cellular apoptosis. PAH metabolism-dependent necroptosis appeared to be responsible for the development of the secondary apoptosis. Hepatocyte exposure induced a necroptosis-dependent release of extracellular vesicles (EVs), that appeared to be protective against necroptosis; however, those necroptotic EVs triggered apoptosis in recipient hepatocytes. Blocking of ASGR EV receptors with asialofetuin inhibited the interaction of EVs with hepatocytes and hence apoptosis. In conclusion, EV release seems to be crucial to avoid necroptosis, but inhibition of EV uptake can protect against apoptosis.

Trimester-specific associations of exposure to epoxide alkanes, alkenals, and 1,3-butadiene with preschool children's intellectual development: A birth cohort study in Wuhan, China

The impact of prenatal exposure to contaminants with neurotoxicity like epoxide alkanes (ethylene oxide, propylene oxide), alkenals (acrolein, crotonaldehyde), and 1,3-butadiene on children's intellectual development remains underreported, and related sensitive window is of interest. In this cohort study, metabolites of these contaminants were measured in 3,081 urine samples from 1,027 pregnant women across three trimesters. Children's intelligence quotient was evaluated at 4-6 years old. Generalized estimating equation models showed that higher urinary concentrations of 2-hydroxypropyl mercapturic acid (a metabolite of propylene oxide), 3-hydroxypropyl mercapturic acid (HPMMA, a metabolite of crotonaldehyde), and the sum of acrolein metabolites in the first trimester were associated with lower visual spatial index (VSI), working memory index (WMI), or processing speed index scores. Quantile g-computation models revealed that co-exposure to these contaminants in the first trimester were associated with lower VSI (β = -0.98, 95 % CI: -1.94, -0.03) and WMI (β = -0.86, 95 % CI: -1.66, -0.06) scores, with HPMMA as the major contributor. These results suggested that early pregnancy could be a sensitive window during which exposure to propylene oxide, crotonaldehyde, and acrolein may impair offspring's intellectual development.

The association analysis between exposure to volatile organic compounds and fatty liver disease in US Adults

BACKGROUND

Limited epidemiological research has explored the associations between ambient volatile organic compounds (VOCs) and fatty liver disease (FLD). This study aimed to explore the associations between VOCs and FLD and liver function biomarkers. We obtained urinary concentrations of VOCs metabolites from NHANES.

METHODS

Weighted logistic regression models were employed to investigate the relationships between VOCs and FLD risk, including alcoholic FLD (AFLD) and non-alcoholic FLD (NAFLD). The associations of VOCs and liver function biomarkers were also investigated using weighted linear regression.

RESULTS

Among the 2050 participants, 774 were classified as having FLD. After adjustment, each log-transformed SD increase in N-Acetyl-S-(2-carboxyethyl)-l-cysteine (CEMA), 2-Aminothiazoline-4-carboxylicacid (ATCA), and trans-trans-muconic-acid (MUCA) had a OR (95%CI) of 1.30 (1.06-1.61; P-trend=0.014), 1.34 (1.12-1.61; P-trend=0.002), and 1.22 (1.01-1.47; P-trend=0.035), respectively. ATCA and MUCA were associated with higher risks of NAFLD (OR=1.47, 95%CI: 1.20-1.79, and OR=1.26, 95%CI: 1.02-1.56, respectively). VOCs were positively associated with gamma glutamyl transaminase (GGT) and C-reactive protein (CRP), while inversely associated with albumin, total protein and alanine aminotransferase (ALT) (P < 0.05).

CONCLUSIONS

Urinary metabolites of VOCs have been found to be strongly correlated with a higher risk of FLD and NFALD, and impaired liver function. These novel findings merit further prospective studies to comprehend the effect of VOCs on liver diseases.

Association of exposure to multiple volatile organic compounds with ultrasound-defined hepatic steatosis and fibrosis in the adult US population: NHANES 2017-2020

Objective

Volatile organic compounds (VOCs) are pervasive environmental pollutants known to impact human health, but their role in liver steatosis or fibrosis is not fully understood. This study investigates the association of urinary VOC mixtures with the risk of liver steatosis and fibrosis in U.S. adult population.

Methods

Data of 1854 adults from the National Health and Nutrition Examination Survey (NHANES) from 2017.01 to 2020.03 were collected. Vibration Controlled Transient Elastography (VCTE) assessed hepatic steatosis and liver fibrosis via the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), respectively. The study examined the relationship between urinary exposure biomarkers for 20 VOCs and liver health outcomes using multivariate logistic regression and Bayesian Kernel Machine Regression (BKMR) to evaluate the effects of both individual and mixed VOC exposures.

Results

Multivariate logistic regression analysis revealed that exposure biomarkers for acrolein and crotonaldehyde were positively associated with hepatic steatosis. Conversely, biomarkers for styrene, ethylbenzene, and propylene oxide were negatively associated with hepatic steatosis. Furthermore, biomarkers for 1,3-butadiene and xylene were positively associated with liver fibrosis, while ethylbenzene was negatively associated with this condition. BKMR analysis identified a significant positive joint effect of VOC biomarkers on CAP. Notably, when other VOC-EBs were held at median levels, biomarkers for acrolein and 1,3-butadiene exhibited linear correlations with Ln CAP and hepatic Ln LSM, respectively.

Conclusion

The study highlights the potential hepatotoxic effects of VOC mixtures, particularly noting the roles of acrolein and 1,3-butadiene in exacerbating liver steatosis and fibrosis. These findings advocate for further research to explore the mechanistic pathways and conduct longitudinal studies to establish causality and enhance understanding of VOCs' impact on liver health.

Association between volatile organic compounds exposure and infertility risk among American women aged 18-45 years from NHANES 2013-2020

The risk of infertility is progressively escalating over the years, and it has been established that exposure to environmental pollutants is closely linked to infertility. As a prevalent environmental pollutant in daily life, there is still a lack of substantial evidence on the association between volatile organic compounds (VOCs) exposure and infertility risk. This study aimed to examine the association between VOCs exposure and the risk of female infertility in the United States. Participant data sets from three cycles (2013-2020) were collected and downloaded from the National Health and Nutrition Examination Survey (NHANES), including demographics, examination, laboratory and questionnaire data. The baseline characteristics of the included population were evaluated, and the weighted quartile logistic regression was used to analyze the association between the urinary metabolites of VOCs (mVOCs) levels and the risk of infertility. Further exploration of the relationship between mVOCs and infertility was conducted by using 35 and 25 as the cut-off points for age and BMI subgroup analyses, respectively. Restricted cubic spline (RCS) was employed to elucidate the nonlinear relationship between mVOCs and infertility risk. Additionally, the Bayesian kernel machine regression (BKMR) model with 20,000 iterations was applied to elucidate the link between mVOCs and the risk of infertility when exposed to mixed or individual mVOCs. A total of 1082 women aged 18 to 45 years were included in this study, with 133 in the infertility group and 949 in the control group. The analysis of baseline characteristics suggested that urinary 34MHA, AMCC and DHBMA levels were significantly higher in the infertility group compared to the control group (p < 0.05). Quartile logistic regression analysis indicated that AAMA (Q3), AMCC (Q4), CYMA (Q3) and HPMMA (Q3) were positively associated with infertility risk in all models (p < 0.05). Subgroup analysis revealed different risk factors for infertility among various subgroups, with CYMA consistently showing a positive correlation with infertility risk in two age subgroups (p < 0.05). Furthermore, the association between mVOCs and infertility was observed only in the subgroup with BMI ≥ 25 kg/m2. RCS analysis indicated that 2MHA, ATCA, BMA, BPMA, CYMA, 2HPMA, 3HPMA and PGA exhibited linear dose-response relationships with infertility (p > 0.05), while the remaining variables showed nonlinear relationships (p < 0.05). The BKMR model demonstrated that the risk of female infertility exhibited an increasing trend with the accumulation of mVOCs co-exposure. A positive association between the exposure to mVOCs represented by 34MHA and AMCC and the risk of infertility was observed in this research. However, the inherent limitations associated with the cross-sectional study design necessitate the pursuit of additional prospective and experimental research to further elucidate and validate the relationships between various mVOCs exposure and female infertility.

Urinary polycyclic aromatic hydrocarbon metabolites in Chinese pregnant women: Concentrations, variability, predictors, and association with oxidative stress biomarkers

Polycyclic aromatic hydrocarbons (PAHs) are a class of pervasive contaminants having adverse health effects. Urinary monohydroxylated PAHs (OH-PAHs) are commonly employed as biomarkers to estimate PAH exposure levels in humans. However, little is understood about the variability in OH-PAHs among pregnant women across trimesters and their relationship with oxidative stress biomarkers (OSBs). Based on a prospective birth cohort study conducted in Wuhan, China, we selected 644 women who donated (spot) urine samples across different trimesters and measured the urinary concentrations of eight OH-PAHs and three selected OSBs (8-OHG, 8-OHdG, and HNEMA) to explore the relationship between the OH-PAHs and OSBs. Pregnant women were found to be ubiquitously exposed to the PAHs, with detection rates of the OH-PAHs ranging from 86.3% to 100%. 2-Hydroxynaphthalene (2-OH-Nap) had the highest urinary concentrations among the OH-PAHs during the three trimesters (specific gravity-adjusted median values for the first, second, and third trimesters: 1.86, 2.39, and 2.20 ng/mL, respectively). However, low reproducibility of the OH-PAHs was observed across the three trimesters with intraclass correlation coefficients ranged between 0.02 and 0.22. Most urinary OH-PAHs had the highest concentrations at the first trimester and the lowest at the third trimester. Some OH-PAH concentrations were higher in pregnant women with lower educational level [2-hydroxyphenanthrene (2-OH-Phen) and 3-hydroxyphenanthrene (3-OH-Phen)], those who were overweight [2-OH-Nap, 2/3-hydroxyfluorene (2/3-OH-Fluo), 2-OH-Phen, and 4-hydroxyphenanthrene (4-OH-Phen)], those who were unemployed during pregnancy [1-hydroxynaphthalene, 1/9-hydroxyphenanthrene, and 4-OH-Phen], and the samples donated in summer (most OH-PAHs, except for 2-OH-Nap). In multivariable linear mixed-effects model analyses, every OH-PAH was found to be significantly associated with increased levels of the three OSBs. For example, each interquartile range-fold increase in 2/3-OH-Fluo concentration was associated with the largest increase in 8-OHdG (65.4%) and 8-OHG (49.1%), while each interquartile range-fold increase in 3-OH-Phen concentration was associated with the largest increase in HNEMA (76.3%). Weighted quantile sum regression models, which were used to examine the joint effect of OH-PAH mixture on the OSBs, revealed positive associations between the OH-PAH mixture exposure and the OSBs. Specifically, 2/3-OH-Fluo and 2-OH-Nap were the major contributors in the association with oxidative damage of nucleic acids (8-OHdG and 8-OHG), while hydroxyphenanthrenes and 1-hydroxypyrene were the major contributors in the association with oxidative damage of lipid (HNEMA). Further work is required to examine the potential mediating role of oxidative stress in the relationship of adverse health outcomes with elevated PAH exposure among pregnant women.

The potential health risks of N,N-dimethylformamide: An updated review

N,N-dimethylformamide (DMF) is a universally used industrial material with exponential growth in production and consumption worldwide. The frequently reported occupational DMF poisoning cases in some countries and the gradually recognized unavoidable health risks to the general population highlight that DMF should still be a matter of concern. Previous studies have demonstrated that the liver is the primary target organ of DMF exposure and multiple mechanisms have been revealed. However, most of these studies investigate the detrimental effects of acute and subacute DMF exposure, while the effects of chronic DMF exposure are rarely studied. Furthermore, the key mechanism for the acute hepatotoxicity of DMF remains to be elucidated. Future research may focus on the identification of efficient preventive measures against the toxicity of DMF to occupational workers, the investigation of the detrimental effects of DMF at environmentally relevant doses, and the studies on the elimination and recycling of DMF in industrial wastes. Herein, we present an updated review of the metabolism of DMF, the biomarker of DMF exposure, underlying molecular mechanisms of DMF-induced hepatotoxicity, and the toxicity of DMF to both occupational workers and general populations and discuss the possible directions in future studies.

Biphasic effects of ethanol consumption on N,N-dimethylformamide-induced liver injury in mice

N,N-Dimethylformamide (DMF) is a well-documented occupational hazardous material, which can induce occupational liver injury. The current study was designed to investigate whether ethanol consumption can affect DMF-induced hepatotoxicity and the potential underlying mechanisms involved. We found that a single dose of ethanol (1.25, 2.5, or 5 g/kg bw by gavage) significantly repressed the increase in serum alanine transaminase (ALT) and aspartate transaminase (AST) activities and alleviated the liver histopathological changes in mice challenged with 3 g/kg DMF. In contrast, long-term moderate drinking (2.5 g/kg bw) significantly aggravated the repeated DMF (0.7 g/kg bw) exposure-induced increase in the serum ALT and AST activities. Mechanistically, acute ethanol consumption suppressed DMF-induced activation of the NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome, while long-term moderate ethanol consumption promoted hepatocyte apoptosis in the mouse liver. Notably, cytochrome P4502E1 (CYP2E1) protein level and activity in mouse livers were not significantly affected by ethanol per se in the two models. These results confirm that regular drinking can increase the risk of DMF-induced hepatotoxicity, and suggest that DMF-handling workers should avoid consuming ethanol to reduce the risk of DMF-indued liver injury.

A review of disrupted biological response associated with volatile organic compound exposure: Insight into identification of biomarkers

Volatile organic compounds (VOCs) are widespread harmful atmospheric pollutants, which have long been concerned and elucidated to be one of the risks of acute and chronic diseases for human, such as leukemia and cancer. Although numerous scientific studies have documented the potential adverse outcomes caused by VOC exposure, the mechanisms which biological response pathways of these VOC disruption remain poorly understood. Therefore, the identification of biochemical markers associated with metabolism, health effects and diseases orientation can be an effective means of screening biological targets for VOC exposure, which provide evidences to the toxicity assessment of compounds. The current review aims to understand the mechanisms underlying VOCs-elicited adverse outcomes by charactering various types of biomarkers. VOCs-related biomarkers from three aspects were summarized through in vitro, animal and epidemiological studies. i) Unmetabolized and metabolized VOC biomarkers in human samples for assessing exposure characteristics in different communities; ii) Adverse endpoint effects related biomarkers, mainly including (anti)oxidative stress, inflammation response and DNA damage; iii) Omics-based molecular biomarkers alteration in gene, protein, lipid and metabolite aspects associated with biological signaling pathway disorders response to VOC exposure. Further research, advanced machine learning and bioinformation approaches combined with experimental results are urgently needed to ascertain the selection of biomarkers and further illuminate toxic mechanisms of VOC exposure. Finally, VOCs-induced disease causes can be predicted with proven results.

Associations of exposure to volatile organic compounds with sleep health and potential mediators: analysis of NHANES data

Objective

The effect of environmental pollution on sleep has been widely studied, yet the relationship between exposure to volatile organic compounds (VOCs) and sleep health requires further exploration. We aimed to investigate the single and mixed effect of urinary VOC metabolites on sleep health and identify potential mediators.

Methods

Data for this cross-sectional study was collected from the National Health and Nutrition Examination Surveys (NHANES) (2005-2006, 2011-2014). A weighted multivariate logistic regression was established to explore the associations of 16 VOCs with four sleep outcomes. Following the selection of important VOCs through the least absolute shrinkage and selection operator (LASSO) regression, principal component analyses (PCA), weight quantile sum (WQS), and Bayesian kernel machine regression (BKMR) analyses were conducted to explore the associations between exposure to single and mixed VOCs and sleep outcomes, as well as identify the most contributing components. A mediation analysis was performed to explore the potential effect of depression scores.

Results

Of the 3,473 participants included in the study, a total of 618 were diagnosed with poor sleep patterns. In logistic regression analyses, 7, 10, 1, and 5 VOCs were significantly positively correlated with poor sleep patterns, abnormal sleep duration, trouble sleeping, and sleep disorders, respectively. The PCA analysis showed that PC1 was substantially linked to a higher risk of poor sleep patterns and its components. The WQS model revealed a positive association between VOC mixture of increased concentrations and poor sleep patterns [OR (95% CI): 1.285 (1.107, 1.493)], abnormal sleep duration [OR (95% CI): 1.154 (1.030, 1.295)], trouble sleeping [OR (95% CI): 1.236 (1.090, 1.403)] and sleep disorders [OR (95% CI): 1.378 (1.118, 1.705)]. The BKMR model found positive associations of the overall VOC exposure with poor sleep patterns, trouble sleeping, and sleep disorders. PCA, WQS, and BKMR models all confirmed the significant role of N-acetyl-S-(N-methylcarbamoyl)-l-cysteine (AMCC) in poor sleep patterns and its components. The depression score was a mediator between the positive VOC mixture index and the four sleep outcomes.

Conclusion

Exposure to single and mixed VOCs negatively affected the sleep health of American population, with AMCC playing a significant role. The depression score was shown to mediate the associations of VOC mixtures with poor sleep patterns and its components.

Sleep and liver function biomarkers in relation to risk of incident liver cancer: a nationwide prospective cohort study

BACKGROUND

To assess the largely undetermined separate and joint effects of sleep and liver function biomarkers on liver cancer.

METHODS

Data of 356,894 participants without cancer at baseline in the UK Biobank were analyzed. Sleep score was evaluated using five sleep traits (sleep duration, chronotype, insomnia, snoring, and excessive daytime sleepiness) and dichotomized into healthy or unhealthy sleep. Circulating liver function biomarkers were measured. Cox proportional hazard model was performed to investigate the independent and joint associations of sleep and liver function biomarkers with liver cancer incidence.

RESULTS

After a median follow-up time of 13.1 years, 394 cases of incident liver cancer were documented. The multivariable-adjusted hazard ratio (HR) for liver cancer was 1.46 (95% confidence interval: 1.15-1.85) associated with unhealthy sleep (vs. healthy sleep), and was 1.17 (1.15-1.20), 1.20 (1.18-1.22), 1.69 (1.47-1.93), 1.06 (1.06-1.07), 1.08 (1.07-1.09), 1.81 (1.37-2.39), or 0.29 (0.18-0.46) associated with each 10-unit increase in alanine transaminase (ALT), aspartate transaminase (AST), total bilirubin (TBIL), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), total protein (TP), or albumin (ALB), respectively. Individuals with unhealthy sleep and high (≥ median) ALT, AST, TBIL, GGT, ALP, or TP or low (< median) ALB level had the highest HR of 3.65 (2.43-5.48), 4.03 (2.69-6.03), 1.97 (1.40-2.77), 4.69 (2.98-7.37), 2.51 (1.75-3.59), 2.09 (1.51-2.89), or 2.22 (1.55-3.17) for liver cancer, respectively. Significant additive interaction of unhealthy sleep with high TP level on liver cancer was observed with relative excess risk due to an interaction of 0.80 (0.19-1.41).

CONCLUSIONS

Unhealthy sleep was associated with an increased risk of liver cancer, especially in participants with lower ALB levels or higher levels of ALT, AST, TBIL, GGT, ALP, or particularly TP.

Discovery and validation of COX2 as a target of flavonoids in Apocyni Veneti Folium: Implications for the treatment of liver injury

ETHNOPHARMACOLOGICAL RELEVANCE

Apocyni Veneti Folium (AVF), a popular traditional Chinese medicine (TCM), is known for its effects in soothing the liver and nerves and eliminating heat and water. It is relevant from an ethnopharmacological perspective. Pharmacological research has confirmed its benefits on antihypertension, antihyperlipidemia, antidepression, liver protection, immune system boosting, antiaging, and diabetic vascular lesions. Previous studies have shown that flavonoids, the active ingredients, have a hepatoprotective effect. However, the exact mechanism has not been clarified.

AIM OF THE STUDY

This study aimed to identify the active flavonoids in AVF and their corresponding targets for liver injury. Multiple methods were introduced to confirm the targets.

MATERIAL AND METHODS

AVF compounds were analyzed using liquid chromatography-mass spectrometry (LC-MS). Then, network pharmacology was utilized to screen potential hepatoprotection targets of the compounds. An enzyme activity assay was performed to determine the effect of the compounds on the targets. Biolayer interferometry (BLI) was applied to confirm the direct interaction between the compounds and the targets.

RESULTS

A total of 71 compounds were identified by LC-MS and 19 compounds and 112 shared targets were screened using network pharmacology. These common targets were primarily involved in the TNF signaling pathway, cancer pathways, hepatitis B, drug responses, and negative regulation of the apoptotic process. Flavonoids were the primary pharmacological substance basis of AVF. The cyclooxygenase 2 (COX2) protein was one of the direct targets of flavonoids in AVF. The enzyme activity assay and BLI-based intermolecular interactions demonstrated that the compounds astragalin, isoquercitrin, and hyperoside exhibited stronger inhibition of enzyme activity and a higher affinity with COX2 compared to epigallocatechin, quercetin, and catechin.

CONCLUSIONS

COX2 was preliminarily identified as a target of flavonoids, and the mechanism of the hepatoprotective effect of AVF might be linked to flavonoids inhibiting the activity of COX2. The findings can establish the foundation for future research on the traditional hepatoprotective effect of AVF on the liver and for clinical studies on liver disorders.

Single and mixed effects of multiple volatile organic compounds exposure on hematological parameters in the U.S. adult population

BACKGROUND

Most research exploring the correlation between volatile organic compounds (VOCs) and hematological parameters have focused on single VOCs. Our study aimed to explore the single and combined effects of VOCs on hematological parameters through three statistical models.

METHODS

Data from 4 cycles of the National Health and Nutrition Examination Survey (NHANES) were used in this study. The correlations between single exposure to 16 VOCs and hematological parameters in the general population were assessed by weighted multiple linear regression. Weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were used to explore the relationship between the combined important VOCs selected by the least absolute shrinkage and selection operator (LASSO) and hematological parameters, as well as the effects of smoking status on them.

RESULTS

A total of 4089 adults were included in the study. We found that a variety of VOCs were significantly associated with hematological parameters. Among them, N-acetyl-S-(benzyl)-l-cysteine (BMA) was significantly negatively correlated with white blood cell (WBC), red blood cell (RBC), lymphocyte, and neutrophil counts. N-acetyl-S-(3-hydroxypropyl-1-methyl)-l-cysteine (HPMMA) was significantly positively correlated with WBC, monocyte, lymphocyte, and neutrophil counts. In the WQS analysis, the WQS index of the VOCs mixtures was positively correlated with WBC (β: 0.031; P < 0.001), monocyte (0.023; P = 0.021), and neutrophil (0.040; P = 0.001) counts, while negatively associated with RBC (-0.013; P < 0.001) counts. The BKMR model revealed that combined exposure to VOCs levels ≥70th percentile was significantly associated with lower RBC counts, and BMA was identified as the dominant contributor. Smoking significantly influenced the relationship between VOCs and hematological parameters.

CONCLUSIONS

Our study indicated the effects of single and overall VOCs exposure on hematological parameters and suggested the hematotoxicity as well as pro-inflammatory effects of VOCs, which had strong public health implications for reducing the potential health hazards of VOCs exposure to the hematologic system.

Effect of brominated flame retardants exposure on liver function and the risk of non-alcoholic fatty liver disease in the US population

BACKGROUND

The relationship between brominated flame retardants (BFRs) exposure and the human liver was still not well understood.

METHODS

A total of 3108 participants (age > 12) from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2005 to 2016 were included as the study population, with nine BFRs exhibiting a detection rate of over 70% serving as the exposure factor. The singular effects and combined effects of BFRs exposure on liver injury, non-alcoholic fatty liver disease (NAFLD), and advanced hepatic fibrosis (AHF) were evaluated separately. Finally, COX regression was employed to explore the hazard ratios associated with individual BFRs.

RESULTS

In our analysis of individual exposures, we found significant positive association of PBB153 with alanine aminotransferase (ALT), PBB153 with aspartate aminotransferase (AST), PBDE47, PBDE85, PBDE99, PBDE100, and PBDE154 with alkaline phosphatase (ALP), PBDE28 and PBB153 with gamma-glutamyl transaminase (GGT), PBB153 with the risk of NAFLD and AHF; and significant negative association of PBB153 with ALP, PBDE28, PBDE47, PBDE99, PBDE100, PBDE85, PBDE209, and PBDE154 with albumin (ALB), PBB153 with AST/ALT. The nonlinear analysis results from Restricted Cubic Spline (RCS) further validated these associations (all P<0.05). In the mixed analysis combining Weighted Quantile Sum (WQS) regression and Quantile G-computation (QGC) analysis, BFRs were positively associated with ALT (β>0, P<0.001), GGT (β>0, P<0.001), and the risk of NAFLD (OR>1, P=0.007). Conversely, BFRs exhibited significant negative correlations with ALP (β<0, P<0.001), ALB (β<0, P<0.001), and AST/ALT (β<0, P<0.001). Furthermore, the COX regression analysis revealed that PBB153 had the highest hazard ratio among the BFRs.

CONCLUSIONS

BFR exposure may increase the risk of liver injury and NAFLD, with no significant association with AHF risk. The impact of BFR exposure on liver health should not be overlooked, especially in individuals residing in impoverished areas.

Effects of Sophora alopecuroides in a High-Concentrate Diet on the Liver Immunity and Antioxidant Function of Lambs According to Transcriptome Analysis

The purpose of this study was to determine the effects of Sophora alopecuroides (SA) on liver function, liver inflammatory factor levels, antioxidant indexes and transcriptome in sheep. Twenty-four 3-month-old healthy Dumont hybrid lambs weighing 25.73 ± 2.17 kg were randomly divided into three groups: C1 (the control group), fed a concentrate-to-forage ratio of 50:50; H2 (the high-concentration group), fed a concentrate-to-forage ratio of 70:30; and S3 (the SA group), fed a concentrate-to-forage ratio of 70:30 + 0.1% SA. The results showed that the rumen pH values of the C1 and S3 groups were significant or significantly higher than that of the H2 group (p < 0.05 or p < 0.01). The serum ALT, AST and LDH activities and the LPS and LBP concentrations in the sheep serum and liver in the H2 group were significantly or extremely significantly higher than those in the C1 and S3 groups (p < 0.01), and the IL-10 content and SOD, GPX-PX and T-AOC activities showed the opposite trend (p < 0.05 or p < 0.01). KEGG enrichment analysis showed that the differentially expressed genes were significantly enriched in the ECM-receptor interaction and focal adhesion pathways, which are closely related to immune and antioxidant functions (p-adjust < 0.1). In summary, SA could improve the immune and antioxidant functions of lamb livers under high-concentrate conditions and regulate the mechanism of damage on sheep livers, which is caused by high-concentrate diets and through the expression of related genes in the ECM/FAs pathway.

Association between mixed urinary metal exposure and liver function: analysis of NHANES data

Metals have been reported to affect liver functions; however, the association between mixed metal exposure in the urine and liver functions remains unclear. The present study analyzed data from the National Health and Nutrition Examination Survey (NHANES) program collected in 2005-2018. Weighted multiple linear regression and Bayesian kernel machine regression (BKMR) were used to explore the relationship between mixed urinary metal contents and liver function tests (LFTs). A total of 8158 participants were analyzed in this study. Multiple methods suggested that cadmium (Cd) was significantly positively related to LFTs, while cobalt (Co) was negatively related to LFTs. Meanwhile, some other metals showed a significant relationship with some indicators of LFTs. Urine metal is related to LFTs, with Cd and Co content changes being closely related to LFTs. The metal in urine may represent a marker for predicting liver dysfunction. Further studies are needed to verify this hypothesis.

Synergistic impact of co-exposures to whole blood metals on chronic kidney disease in general US adults: a cross‑sectional study of the National Health and Nutrition Examination Survey 2011-2020

The impact of exposure to metals on chronic kidney disease (CKD) has only been investigated in two-way or single metal interactions in previous studies. We investigated the associations between five single metals in blood and their mixed exposure and CKD by using the machine learning approach. Relevant data were extracted from the National Health and Nutrition Examination Survey (NHANES 2011-2020), and the level of five metals in blood detected by inductively coupled plasma mass spectrometry was considered as exposures, namely, cadmium (Cd), lead (Pb), total mercury (Hg), manganese (Mn), and selenium (Se). The correlations between individual metal and metal mixtures and CKD were then evaluated by survey-multivariable logistic regression (SMLR), generalized weighted quantile sum (WQS), and Bayesian kernel machine regression (BKMR). Altogether, our study included 12,412 participants representing 572.6 million non-institutionalized US adults. Several single metals with the high quartile of exposure showed a positive association with the CKD ratio including Cd [(AOR = 1.873, 95% CI: 1.537, 2.284), Q4], Pb [(AOR = 1.559, 95% CI: 1.295, 1.880), Q4], and total Hg [(AOR = 1.169, 95% CI: 1.018, 1.343), Q2], while Mn [(AOR = 0.796, 95% CI: 0.684, 0.927), Q2] and Se [(AOR = 0.805, 95% CI: 0.664, 0.976), Q4] were negatively associated with the CKD ratio. In light of the positive fit of the WQS regression model, a significantly positive correlation was found between mixed metals and CKD (AOR = 1.373, 95% CI: 1.224, 1.539) after full covariate adjustment, and a similar finding was also detected in the BKMR model. Our study revealed that each single metal including Cd, Pb, and total Hg might have a positive association with CKD while this association was negative for both Mn and Se. The five metals might have a positive joint effect on CKD.