Cardiometabolic traits mediated the relationship from urinary polycyclic aromatic hydrocarbons metabolites to heart rate variability reduction: A community-based study

Elevated plasma solMER concentrations link ambient PM2.5 and PAHs to myocardial injury and reduced left ventricular systolic function in children

Exposure to fine particulate matter (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) is known to be associated with the polarization of pro-inflammatory macrophages and the development of various cardiovascular diseases. The pro-inflammatory polarization of resident cardiac macrophages (cMacs) enhances the cleavage of membrane-bound myeloid-epithelial-reproductive receptor tyrosine kinase (MerTK) and promotes the formation of soluble MerTK (solMER). This process influences the involvement of cMacs in cardiac repair, thus leading to an imbalance in cardiac homeostasis, myocardial injury, and reduced cardiac function. However, the relative impacts of PM2.5 and PAHs on human cMacs have yet to be elucidated. In this study, we aimed to investigate the effects of PM2.5 and PAH exposure on solMER in terms of myocardial injury and left ventricular (LV) systolic function in healthy children. A total of 258 children (aged three to six years) were recruited from Guiyu (an area exposed to e-waste) and Haojiang (a reference area). Mean daily PM2.5 concentration data were collected to calculate the individual chronic daily intake (CDI) of PM2.5. We determined concentrations of solMER and creatine kinase MB (CKMB) in plasma, and hydroxylated PAHs (OH-PAHs) in urine. LV systolic function was evaluated by stroke volume (SV). Higher CDI values and OH-PAH concentrations were detected in the exposed group. Plasma solMER and CKMB were higher in the exposed group and were associated with a reduced SV. Elevated CDI and 1-hydroxynaphthalene (1-OHNa) were associated with a higher solMER. Furthermore, increased solMER concentrations were associated with a lower SV and higher CKMB. CDI and 1-OHNa were positively associated with CKMB and mediated by solMER. In conclusion, exposure to PM2.5 and PAHs may lead to the pro-inflammatory polarization of cMacs and increase the risk of myocardial injury and systolic function impairment in children. Furthermore, the pro-inflammatory polarization of cMacs may mediate cardiotoxicity caused by PM2.5 and PAHs.

Ambient PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) associated with pro-thrombotic biomarkers among young healthy adults: A 16 times repeated measurements panel study

Studies have shown that the cardio/cerebrovascular toxicity of ambient PM2.5 is related to its bound polycyclic aromatic hydrocarbons (PAHs). Currently, only a few studies have reported the relationship between PM2.5-bound PAHs and promoted blood coagulation and thrombosis, but there isn't a consistent conclusion. Therefore, we conducted a prospective panel study to investigate the association. Thirty-three young healthy adults participated in sixteen repeated visits from 2014 to 2018 in Tianjin, China. During each visit, three pro-thrombotic biomarkers: ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motif 13), D-dimer and Myeloperoxidase (MPO) were measured. Before each visit, ambient PM2.5 samples were daily collected for one week. Sixteen PAHs were determined using Gas Chromatography-Mass Spectrometer, and the positive matrix factorization (PMF) model was applied to identify the sources. Linear mixed-effects models were fitted to investigate the associations between PM2.5-bound PAHs exposure and the biomarkers. Thirteen time-metrics were defined to identify significant time points of PM2.5-bound PAHs' effects. We observed that the increase of PM2.5-bound PAHs exposure was significantly associated with reduced ADAMTS13, elevated D-dimer and MPO. At lag0, each 5.7 ng/m3 increase in Benzo[j]fluoranthene and per 3.4 ng/m3 increase Dibenz[a,h]anthracene could make a maximum change of -19.08 % in ADAMTS13 and 132.60 % in D-dimer. Additionally, per 16.43 ng/m3 increase in Chrysene could lead to a maximum elevation of 32.14 % in MPO at lag4. The PM2.5-bound PAHs often triggered more significant changes at lag 3,4 and 6. The ambient PM2.5-bound PAHs originated from six sources: coal combustion (43.10 %), biomass combustion (20.77 %), diesel emission (14.78 %), gasoline emission (10.95 %), industrial emission (7.58 %), and cooking emission (2.83 %). The greatest contributors to alterations in ADAMTS13, D-dimer and MPO are industrial emission (-48.43 %), biomass combustion (470.32 %) and diesel emission (13.14 %) at lag4. Our findings indicated that short-term exposure to ambient PM2.5-bound PAHs can induce alterations of pro-thrombotic biomarkers among healthy adults.

Association of urinary polycyclic aromatic hydrocarbon metabolites with gestational diabetes mellitus and gestational hypertension among pregnant women in Southwest China: A cross-sectional study

The association of polycyclic aromatic hydrocarbons (PAHs) with gestational diabetes mellitus (GDM) and gestational hypertension during pregnancy has not yet been established. To investigate the association between PAH exposure and GDM and gestational hypertension, we conducted a cross-sectional study of 4206 pregnant women from the Zunyi birth cohort in southwestern China. Gas chromatography/mass spectrometry was used to detect the urinary levels of 10 monohydroxylated PAHs (OH-PAHs). GDM and gestational hypertension were diagnosed and the relevant information was documented by specialist obstetricians and gynecologists. Logistic regression and restricted cubic spline regression were employed to investigate their single and nonlinear associations. Stratified analyses of pregnancy and body mass index data were conducted to determine their moderating effects on the abovementioned associations. Compared with the first quartile of urinary ∑OH-PAHs, the third or fourth quartile in all study participants was associated with an increased risk of GDM (quartile 3: odds ratio [OR] = 1.35, 95% confidence interval [CI]: 1.03-1.77) and gestational hypertension (quartile 3: OR = 1.88, 95% CI: 1.26-2.81; quartile 4: OR = 1.58, 95% CI: 1.04-2.39), respectively. Nonlinear associations of 1-OH-PYR with GDM (cutoff level: 0.02 μg/g creatinine [Cr]) and 1-OH-PHE with gestational hypertension (cutoff level: 0.06 μg/g Cr) were also observed. In pregnant women with overweight or obesity, 1-OH-PHE and 3-OH-PHE were more strongly associated with gestational hypertension. Our results indicate that exposure to PAH during pregnancy may significantly increase the maternal risks of GDM and gestational hypertension; however, this finding still needs to be confirmed through larger-scale prospective studies and biological evidence.

Association between polycyclic aromatic hydrocarbons exposure with red cell width distribution and ischemic heart disease: insights from a population-based study

This study investigates the association between polycyclic aromatic hydrocarbon (PAH) exposure, red blood cell distribution width (RDW), and ischemic heart disease (IHD) in a sample of 3003 participants from the National Health and Nutrition Examination Survey (NHANES). We hypothesize that RDW may mediate the effect of hydroxylated PAHs (OH-PAH) on IHD. Logistic regression models reveal significant associations between increased urinary PAH metabolite concentrations and IHD, as well as positive associations between PAH metabolites and RDW. Weighted Quantile Sum (WQS) regression and Bayesian Kernel Machine Regression (BKMR) analyses confirm the significant associations of the OH-PAH mixture with IHD and RDW. Mediation analysis demonstrates that RDW partially mediates the relationship between PAH exposure and IHD, accounting for 2-4.6% of the total effects. Our findings highlight the potential underlying mechanisms linking PAH exposure, RDW, and IHD and emphasize the importance of addressing environmental pollutants like PAHs in maintaining cardiovascular health and informing public health policies.

Short-Term Heart Rate Variability in Metabolic Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Our aim was to determine the differences in short-term heart rate variability (HRV) between patients with metabolic syndrome (MS) and healthy controls.

METHODS

We searched electronic databases for primary works with short-term HRV recordings (≤30 min) that made comparisons between individuals with MS versus healthy controls. This systematic review and meta-analysis (MA) was performed according to PRISMA guidelines and registered at PROSPERO (CRD42022358975).

RESULTS

Twenty-eight articles were included in the qualitative synthesis and nineteen met the criteria for the MA. Patients with MS showed decreased SDNN (-0.36 [-0.44, -0.28], p < 0.001), rMSSD (-7.59 [-9.98, -5.19], p < 0.001), HF (-0.36 [-0.51, -0.20], p < 0.00001) and LF (-0.24 [-0.38, -0.1], p = 0.001). In subsequent subanalyses, we found a decrease in SDNN (-0.99 (-1.45, -0.52], p < 0.001), rMSSD (-10.18 [-16.85, -3.52], p < 0.01) and HF (-1.04 [-1.97, -0.1] p < 0.05) in women. In men, only LF showed a significant lower value (-0.26 [-0.5, -0.02], p < 0.05). We could not perform MA for non-linear variables.

CONCLUSIONS

Patients with MS showed changes in time-domain analyses, with lower values in SDNN and rMSSD. Regarding frequency-domain analyses, MS patients showed a decrease in HF and LF When sex was used as a grouping variable, the MA was only possible in one of both sexes (men or women) in rMSSD and LF/HF. Lastly, when data for both men and women were available, subanalyses showed a different behavior compared to mixed analyses for SDNN, HF and LF, which might point towards a different impact of MS in men and women.

Urinary phthalate metabolites and heart rate variability: A panel study

Phthalates exposure is linked with cardiovascular disease. Decreased heart rate variability (HRV) is an early indicator of cardiac autonomic imbalance. We conducted a longitudinal panel study in 127 Chinese adults with 3 repeated visits to explore the associations of individual and mixtures of phthalates exposure with HRV. We quantified 10 urinary phthalate metabolites by gas chromatograph-tandem mass spectrometer (GC-MS/MS) and 6 HRV indices by 3-channel digital Holter monitors. Linear mixed-effect (LME) models and Bayesian kernel machine regression (BKMR) models were separately implemented to evaluate the associations. After multivariate adjustments, we found that urinary mono-ethyl phthalate (MEP), mono-iso-butyl phthalate (MiBP), and mono-n-butyl phthalate (MBP) at lag 0 day were inversely associated with low-frequency power (LF) or total power (TP) (all P-FDR <0.05). In mixture analysis, we observed negative overall associations of phthalate mixtures at lag 0 day with LF or TP, and MiBP was the major contributor. Moreover, stratified analysis suggested that the inverse relationships of MiBP at lag 0 day with LF and TP were more prominent in subjects aged >50 years (all P_interaction < 0.01). Our findings revealed that exposure to individual and mixtures of phthalates, especially MiBP, were related to decreased HRV.

Cross-sectional and longitudinal associations of styrene and ethylbenzene exposure with heart rate variability alternation among urban adult population in China

Styrene and ethylbenzene (S/EB) are the monomers of polystyrene (PS) and polyethylene (PE), respectively, and have been identified as significant hazardous air pollutants by the U.S. Environmental Protection Agency. However, the adverse effects of S/EB on human health, especially cardiovascular health, have not been well established. Urinary biomarker of S/EB exposure and heart rate variability (HRV) were measured in urban adults from the Wuhan-Zhuhai cohort and were repeated after 3-year and 6-year follow-ups. Linear mixed models were used to estimate associations of S/EB exposure biomarker with HRV and longitudinal additional annual change of HRV. The mediating role of transforming growth factor (TGF)-β1 was tested by using mediation analysis. A total of 2842 general adults were included at baseline analysis, and 4748 observations were included in the repeated measurement study. In the cross-sectional analysis, each 1% increment in urinary S/EB exposure biomarker was significantly associated with a 0.106 % (95 % CI: -0.160, -0.052), 0.109 % (-0.169, -0.049), 0.099 % (-0.145, -0.053), 0.040 % (-0.060, -0.020), and 0.031 % (-0.054, -0.007) decrement in low frequency (LF), high frequency (HF), total power (TP), standard deviation of all normal-to-normal intervals (SDNN), and square root of the mean squared difference between adjacent normal-to-normal interval, respectively. Smoking status modified the relationships of urinary S/EB exposure biomarker with TP and SDNN. TGF-β1 mediated 3.09-5.16 % of the association between urinary S/EB biomarker and lower HRV. The follow-up analyses detected a negative association between urinary S/EB exposure biomarker and the additional annual change of LF (β: -0.016; 95 % CI: -0.028, -0.004), HF (-0.014; -0.026, -0.001), and TP (-0.011; -0.021, -0.001). Our findings demonstrated that S/EB exposure was associated with HRV reduction among the general urban adults and the TGF-β pathway may play a part of the mediating role in this association.

Polycyclic aromatic hydrocarbons associated long non-coding RNAs and heart rate variability in coke oven workers

Epidemiological studies have showed that polycyclic aromatic hydrocarbons (PAHs) were associated with heart rate variability (HRV), but the role of long non-coding RNAs (lncRNAs) in the association is unknown. We aimed to identify PAHs-related lncRNAs and assess their associations with HRV among coke oven workers. Differential lncRNAs expression between 12 exposed workers and 12 controls was tested by Human 8X60k LncRNA Arrays in discovery stage, then selected NR_024564 was validated in 353 workers using droplet digital RT-PCR. Microarray results showed that 1234 lncRNAs were downregulated with 805 lncRNAs upregulated in exposed group (≥ 2-fold change). In validation stage, no significant association was observed between NR_024564 and PAH exposure or HRV in total subjects, while urinary 2-hydroxyfluorene (2-OHFlu) was inversely related to root mean square successive difference (RMSSD). However, in current smokers, NR_024564 was inversely related to urinary 2-OHFlu, 2-hydroxyphenanthrene, 1-hydroxypyrene (1-OHP), and total PAHs metabolites (ΣOH-PAHs), of which 1-OHP accounted for the strongest estimation for interaction with smoking status (P_interaction = 0.011). Also, the positive associations of NR_024564 with RMSSD and high frequency power showed an interaction with smoking status (P_interaction = 0.034 and 0.023, respectively). Also, urinary 2-OHFlu and ΣOH-PAHs were inversely associated with RMSSD in current smokers. In addition, elevated NR_024564 was dose-responsive related to increased RMSSD in above high-PAHs groups among smokers (all P_trend < 0.05). Our results revealed that NR_024564 and its interactions with smoking status might act as novel mechanisms regulating the adverse effects of PAHs on HRV.

Exposure to acrylamide and reduced heart rate variability: The mediating role of transforming growth factor-β

The potential adverse health effects of acrylamide have drawn worldwide attention and the World Health Organization has urged further urgent studies on its health threat. Herein we explored the exposure-response relationship and underlying mechanism between internal acrylamide exposure and heart rate variability (HRV) alteration, a marker of cardiac autonomic dysfunction. We measured six HRV indices and two urinary acrylamide metabolites (N-Acetyl-S-(2-carbamoylethyl)-l-cysteine, AAMA; N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-l-cysteine, GAMA) for 2997 general Chinese adults from the Wuhan-Zhuhai cohort, of whom 2414 had data on plasma transforming growth factor-β1 (TGF-β1). The associations among urinary acrylamide metabolites, HRV and TGF-β1 were evaluated by linear mixed models and restricted cubic spline models. The mediating role of TGF-β1 was investigated by conducting mediation analysis. We found significantly negative dose-response relationships of all urinary acrylamide metabolites and TGF-β1 with all six HRV indices after adjusting for potential confounders (all P < 0.05). Urinary GAMA (β=0.074, P < 0.05) rather than AAMA (β=0.024, P > 0.05) was positively and dose-dependently associated with TGF-β1, which in turn significantly mediated 5.71-7.41 % of the GAMA-associated HRV reduction. Our findings suggest for the first time that daily exposure of general population to acrylamide is associated with cardiac autonomic dysfunction, where a mechanism involving TGF-β pathway may be involved.

Inhibition of UDP-glucuronosyltransferases (UGTs) by polycyclic aromatic hydrocarbons (PAHs) and hydroxy-PAHs (OH-PAHs)

Polycyclic aromatic hydrocarbons (PAHs) are known as one of the ubiquitous environmental pollutants caused by unavoidable combustion of by-products. Despite decades of research on adverse health effects towards humans, the effects of PAHs and their hydroxylated metabolites (OH-PAHs) on UDP-glucuronosyltransferases (UGTs) remain unclear. This study aimed to investigate inhibitory effects with structure-dependence of 14 PAHs and OH-PAHs towards the activity of 7 isoforms of UGTs using in vitro recombinant UGTs-catalyzed glucuronidation of 4-methylumbelliferone (4-MU) as the probe reaction. PAHs and OH-PAHs showed inhibitory effects towards different UGT isoforms with different extents. For inhibition kinetics determination, 1-HONAP, 4-HOPHE, 9-HOPHE, and 1-HOPYR were utilized as the representative compounds, and UGT1A6, UGT1A9 and UGT2B7 were chosen as the three representative UGT isoforms. The inhibitory effects of 4-HOPHE, 9-HOPHE and 1-HOPYR on three above UGT isoforms were the same: UGT1A9>UGT1A6>UGT2B; for 1-HONAP, that is UGT1A6>UGT1A9>UGT2B. Molecular docking methods were utilized to find the activity cavity of UGT1A9 and UGT2B7 binding with 1-HONAP and 1-HOPYR. Hydrogen bonds and hydrophobic contacts were mainly contributors to their interactions. In vitro-in vivo extrapolation (IVIVE) showed that high in vivo inhibition possibility exists for the inhibition of OH-PAHs on UGTs. All the results provide a novel viewpoint for an explanation of the toxicity of PAHs and OH-PAHs.

Effects of environmental and lifestyle exposures on urinary levels of polycyclic aromatic hydrocarbon metabolites: A cross-sectional study of urban adults in China

Urinary polycyclic aromatic hydrocarbon (PAH) metabolites, biomarkers of internal PAH exposure, are commonly used to explore the effects of PAH on human health. However, the correlation between environmental PAH exposure and the species or levels of urinary PAH metabolites remains unclear. We collected detailed information on PAH exposure sources, including cigarette smoking, cooking, traffic and diet habits via structured questionnaires, and determined 12 urinary monohydroxylated PAH metabolites (OH-PAHs) among 4092 participants from the Wuhan-Zhuhai cohort. Linear mixed models and generalized linear models were conducted to explore the associations of urinary metabolite levels with single or multiple PAH exposure sources. We also calculated the standardized regression coefficients to further compare the contributions of different sources to urinary OH-PAH levels. Our results showed that increasing levels of urinary 1-, 2-hydroxynaphthalene (1-, 2- OHNa) and 2-hydroxyfluorene (2-OHFlu) were significantly correlated with tobacco smoking (all P < 0.01). The concentrations of 1-, 2- OHNa and 9-hydroxyfluorene (9-OHFlu) were positively correlated with dietary intake (all P < 0.05). Individuals who spent a long time in traffic showed elevated levels of 9-OHFlu and 1-hydroxyphenanthrene (1-OHPh) compared with individuals who spent a short time in traffic (all P < 0.05). Self-cooking was associated only with elevated 1-hydroxypyrene (1-OHP) levels. Moreover, good kitchen ventilation resulted in significantly decreased urinary low-molecular-weight OH-PAH levels. These findings suggested that cigarette smoking, self-cooking, high dietary PAH intake and a long time spent in traffic were associated with increased levels of specific urinary PAH metabolites, and good kitchen ventilation effectively reduced the exposure to low-molecular-weight PAHs in self-cooking participants.

Association between urinary polycyclic aromatic hydrocarbon metabolites and dyslipidemias in the Chinese general population: A cross-sectional study

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been associated with metabolic diseases. However, relationships between PAH exposures and dyslipidemias have not been well addressed.

OBJECTIVES

To investigate associations between urinary PAH metabolite concentrations and dyslipidemias in the general population.

METHODS

Twelve urinary PAH metabolites and four serum lipid profiles were measured in 3640 Chinese adults from the Wuhan-Zhuhai cohort. Dyslipidemias, including hyper-total cholesterol (HyperTC), hyper-triglyceride (HyperTG), hyper-low density lipoprotein cholesterol (HyperLDL-C), and hypo-high density lipoprotein cholesterol (HypoHDL-C) were classified according to the levels of serum lipids. Multiple logistic regression models were used to estimate the associations between urinary PAH metabolites and the prevalence of dyslipidemias. The effects of PAH exposure routes on dyslipidemias were further estimated by stratified analysis.

RESULTS

We found positive exposure-response relationships between urinary PAH metabolites and the prevalence of dyslipidemias. Compared with the lowest tertile of urinary PAH metabolites, increased risk of HyperTC were observed in those in the highest tertiles; The odds ratios (ORs) and 95% confidence intervals were 1.23 (1.03, 1.47), 1.44 (1.21, 1.71), 1.19 (1.01, 1.42), and 1.43 (1.20, 1.71) for 1-OHNa, 9-OHFlu, 1-OHPh, and 4-OHPh, respectively. Participants in the highest tertiles of 1-OHNa and 2-OHFlu had higher risk for HyperLDL-C, and the ORs were 1.21 (1.01, 1.45) and 1.18 (0.98, 1.42), respectively. Among smokers, only urinary 1-OHNa was associated with increased risk of HyperTC (1.36, 1.08-1.73) and HyperLDL-C (1.33, 1.01-1.74). While the increasing urinary levels of 9-OHFlu, 1-OHPh, and 4-OHPh were significantly associated with increased risk of HyperTC among non-smokers. In addition, the associations between urinary PAH metabolites and dyslipidemias were more pronounced among non-smokers who are cooked for themselves and had long-term traffic exposure.

CONCLUSION

Elevated urinary PAH metabolites were associated with increased risks of HyperTC and HyperLDL-C. The source of PAH exposure could modify PAH species that affect dyslipidemias.