The modifying effect of trait anxiety on the association of fine particulate matter with heart rate variability variables.

BACKGROUND: Previous studies have shown that exposures to ambient particulate matter with aerodynamic diameter <2.5 µm (PM2.5) and stress are associated with adverse cardiovascular health effects. OBJECTIVES: To investigate the potential modifying effect of trait anxiety on the association between short-term exposures to PM2.5 and HRV variables. METHODS: A panel of 92 middle-aged and elderly adults in Tianjin and Shanghai were recruited for repeated follow-ups with measurements of 24-h personal exposures to air pollutants and Holter ECG monitoring. Heart rate variability (HRV) variables calculated over 5-minute segments during the 24 h, including low frequency power (LF), high frequency power (HF), standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive differences (rMSSD), were included in the analysis. The Trait Anxiety Inventory was used to investigate the long-term general anxiety level of the participants. Generalized linear mixed-effects model was used to analyze the association between exposure factors and HRV variables, and potential effect modification by trait anxiety. RESULTS: Data on 87 participants were included in final analysis after exclusions. Higher exposure to PM2.5 was associated with lower levels of LF, HF, SDNN and rMSSD, and the largest decreases in LF, HF, SDNN and rMSSD were found at 3-h moving average. Trait anxiety significantly modified the associations of PM2.5 with LF, HF, SDNN and rMSSD, with stronger inverse associations found in high trait anxiety group than in low trait anxiety group. For an IQR (27.3 µg/m³) increase in PM2.5 at 3-h moving average, there were decreases of 3.50% (95% CI: -4.46%, -2.54%) and 3.50% (95% CI: -4.49%, -2.50%) in the high trait anxiety group, and decreases of 0.81% (95% CI: -1.22%, -0.40%) and 0.65% (95% CI: -1.07%, -0.23%) in the low trait anxiety group in HF and rMSSD, respectively (both p for interaction<0.01). CONCLUSION: Our study suggests that trait anxiety could modify the association of short-term exposure to PM2.5 with HRV variables, indicating that higher trait anxiety may increase the cardiac susceptibility to air pollution in the study participants.

Ambient particulate air pollution, blood cell parameters, and effect modification by psychosocial stress: Findings from two studies in three major Chinese cities.

The associations between particulate matter (PM) exposure, psychosocial stress and blood cell parameters are bringing novel insights to characterize the early damage of multiple diseases. Based on two studies conducted in three Chinses cities using cross-sectional (Beijing, 425 participants) and panel study (Tianjin and Shanghai, 92 participants with 361 repeated measurements) designs, this study explored the associations between short-term exposure to ambient PM and blood cell parameters, and the effect modification by psychosocial stress. Increasing PM2.5 exposure was significantly associated with decreases in red blood cell (RBC) count and mean corpuscular hemoglobin concentration (MCHC), and increases in mean corpuscular volume (MCV), platelets count (PLT) and platelet hematocrit (PCT) in both studies. For instance, a 10 µg/m3 increment in PM2.5 concentration was associated with a 1.04% (95%CI: 0.16%, 1.92%) increase in PLT (4-d) and a 1.09% (95%CI: 0.31%, 1.87%) increase in PCT (4-d) in the cross-sectional study, and a 0.64% (95%CI: 0.06%, 1.22%) increase in PLT (1-d) and a 0.72% (95%CI: 0.33%, 1.11%) increase in PCT (1-d) in the panel study, respectively. In addition, stronger increases in MCV, PLT, and PCT associated with PM2.5 exposure were found in higher psychosocial stress group compared to lower psychosocial stress group (p for interaction <0.10), indicating that blood cell parameters of individuals with higher psychosocial stress might be more susceptible to the early damages of PM2.5 exposure.

Transgenerational male reproductive effect of prenatal arsenic exposure: abnormal spermatogenesis with Igf2/H19 epigenetic alteration in CD1 mouse.

Developmental exposure to environmental toxicants can induce transgenerational reproductive disease phenotypes through epigenetic mechanisms. We treated pregnant CD-1 (F0) mice with drinking water containing sodium arsenite (85 ppm) from days 8 to 18 of gestation. Male offspring were bred with untreated female mice until the F3 generation was produced. Our results revealed that F0 transient exposure to arsenic can cause decreased sperm quality and histological abnormalities in the F1 and F3. The overall methylation status of Igf2 DMR2 and H19 DMR was significantly lower in the arsenic-exposed group than that of the control group in both F1 and F3. The relative mRNA expression levels of Igf2 and H19 in arsenic-exposed males were significantly increased in both F1 and F3. This study indicates that ancestral exposure to arsenic may result in transgenerational inheritance of an impaired spermatogenesis phenotyping involving both epigenetic alterations and the abnormal expression of Igf2 and H19.

Long-term exposure to high particulate matter pollution and incident hypertension: a 12-year cohort study in northern China.

Numerous cohort studies have reported the association of long-term exposure to particulate matter <10 µm in diameter (PM10) and hypertension in American and European countries. However, these results have been inconsistent and subject to various confounding factors. The study aimed to explore the effect of long-term exposure to high-level concentrations of PM10 on incident hypertension in a large-scale cohort from northern China. A retrospective cohort study of 39,054 participants aged between 23 and 98 years old from four cities in northern China was followed from 1998 to 2009. Excluding those with hypertension, 37,386 non-hypertensive participants (overall population) were followed for self-reported hypertension. The individuals' exposure to PM10 was the mean concentration during the follow-up period, according to the data of local environmental monitoring centers. Hazard ratios (HRs) were calculated by Cox proportional hazards models. The adjusted potential confounding factors included sociodemographic information, lifestyle, and diet. There were 2619 (7.0%) incident cases of hypertension among the overall population. In multivariable models, the HR (95% CI) of incident hypertension was 1.537 (1.515, 1.560) for each 10 µg/m3 increase in PM10. Stratified analyses showed individuals (age <65) were prone to developing hypertension. Moreover, the effects of PM10 increased and produced an HR (95% CI) of 1.555 (1.527, 1.584) for the healthy population in the sensitivity analysis. We found that the association between long-term exposure to PM10 air pollution and incident hypertension was significantly positive.

Associations between the incidence and mortality rates of type 2 diabetes mellitus and long-term exposure to ambient air pollution: A 12-year cohort study in northern China.

BACKGROUND: Ambient air pollution has recently been related to type 2 diabetes mellitus (T2DM), a disease that has caused an economic and health burden worldwide. Evidence of an association between air pollution and T2DM was reported in the United States and Europe. However, few studies have focused on the association with high levels of air pollutants in a developing country. OBJECTIVES: We conducted a 12-year cohort study to assess the incidence and mortality of T2DM associated with long-term exposure to PM10, SO2, and NO2. METHODS: A retrospective cohort with participants from four cities in northern China was conducted to assess mortality and incidence of T2DM from 1998 to 2009. Incidence of T2DM was self-reported, and incident intake of an antidiabetic drug or injection of insulin simultaneously and mortality of T2DM was obtained from a family member and double checked against death certificates provided from the local center for disease control and prevention. Individual pollution exposures were the mean concentrations of pollutants estimated from the local environmental monitoring centers over the survival years. Hazard ratios (HRs) were estimated using Cox regression models after adjusting for potential confounding factors. RESULTS: A total of 39 054 participants were recruited into the mortality cohort, among which 59 subjects died from T2DM; 38 529 participants were analyzed in the incidence cohort, and 1213 developed new cases of T2DM. For each 10 µg/m3 increase in PM10, SO2, and NO2, the adjusted HRs and 95% confidence interval (CI) for diabetic incidence were 1.831 (1.778, 1.886), 1.287 (1.256, 1.318), and 1.472 (1.419, 1.528), respectively. Similar results can be observed in the analysis of diabetic mortality with HRs (95% CI) up to 2.260 (1.732, 2.950), 1.130 (1.042, 1.225), and 1.525 (1.280, 1.816), respectively. CONCLUSIONS: Our results suggested that long-term exposure to high levels of PM10, SO2, and NO2 increase risk of incident and mortality of T2DM in China.

BDE-47 Decreases Progesterone Levels in BeWo Cells by Interfering with Mitochondrial Functions and Genes Related to Cholesterol Transport.

Polybrominated diphenyl ethers (PBDEs) have been reported to exert reproductive endocrine toxicity, but the mechanisms for this process remain unclear. Currently available studies have concentrated on the enzymatic reactions during steroidogenesis, but the results are not consistent. In this study, we explored the effects of 2,2',4,4'-tertrabromodiphenyl ether (BDE-47) on progesterone biosynthesis and the potential mechanisms in human placental choriocarcinoma cells. The results showed that BDE-47 decreased progesterone production in a dose-dependent manner but had no effect on key enzymes (Cyp11a1 and 3ß-HSD). BDE-47 exposure depolarized the mitochondrial membrane potential and downregulated adenosine triphosphate levels. The gene expression levels of Mfn2, Tspo, Atad3, Vdac1, Fis1, and Drp1, which are involved in mitochondrial dynamics and cholesterol transport, were disturbed. The demethylation of some CpG loci of mitochondrial biomarkers (Drp1, Opa1, Vdac2, and Atad3) was induced in the 1 µM BDE-47 exposure group, but no methylation change was observed with 50 µM treatment. Our findings unveiled that the reduction of progesterone synthesis induced by BDE-47 might be associated with cholesterol transportation, mitochondrial dynamics, and mitochondrial functions. These findings provide substantial data on the reproductive endocrine toxicity of PBDEs.

Association between MTHFR A1298C polymorphism and male infertility: A meta-analysis.

There have been several epidemiological studies evaluating the potential association between the methylenetetrahydrofolate reductase (MTHFR) A1298C polymorphism and the risk of male infertility. However, the results obtained were inconsistent. Therefore, we performed a meta-analysis to further examine the association between the MTHFR A1298C polymorphism and male infertility. A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to January 15th, 2016. A total of 20 studies with 4293 cases and 4507 controls were included. An odds ratio (OR) and a 95% confidence interval (95% CI) were calculated to assess the strength of the association. A cumulative meta-analysis, sensitivity analysis and assessment of the publication bias were also performed in this study. The results showed that in the overall analysis, the association between the MTHFR A1298C polymorphism and male infertility was not significant. A stratified analysis by ethnicity revealed a significant increase in the risk of male infertility in the Asian population with the MTHFR A1298C polymorphism (especially in the heterozygote model: OR=1.20, 95% CI=1.01-1.44, P=0.994; the dominant model: OR=1.23, 95% CI=1.04-1.45, P=0.996; and the allele model: OR=1.20, 95% CI=1.04-1.39, P=0.985) but not in the Caucasian population. In the stratified analyses, no significant association was observed between the different types of male infertility. This meta-analysis suggests the MTHFR A1298C polymorphism may be a potential risk factor for male infertility, especially in the Asian population.

Association between MTHFR A1298C Polymorphism and Male Infertility: A Meta-analysis / 华中科技大学学报（医学）（英德文版）

There have been several epidemiological studies evaluating the potential association between the methylenetetrahydrofolate reductase (MTHFR) A1298C polymorphism and the risk of male infertility.However,the results obtained were inconsistent.Therefore,we performed a meta-analysis to further examine the association between the MTHFR A1298C polymorphism and male infertility.A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to January 15th,2016.A total of 20 studies with 4293 cases and 4507 controls were included.An odds ratio (OR) and a 95％ confidence interval (95％ CI) were calculated to assess the strength of the association.A cumulative meta-analysis,sensitivity analysis and assessment of the publication bias were also performed in this study.The results showed that in the overall analysis,the association between the MTHFR A1298C polymorphism and male infertility was not significant.A stratified analysis by ethnicity revealed a significant increase in the risk of male infertility in the Asian population with the MTHFR A1298C polymorphism (especially in the heterozygote model:OR=l.20,95％ CI=1.01-1.44,P=0.994;the dominant model:OR=1.23,95％ CI=1.04-1.45,P=0.996;and the allele model:OR=l.20,95％ CI=1.04-1.39,P=0.985) but not in the Caucasian population.In the stratified analyses,no significant association was observed between the different types of male infertility.This meta-analysis suggests the MTHFR A1298C polymorphism may be a potential risk factor for male infertility,especially in the Asian population.