Chronic carbon monoxide exposure is associated with the increases in carotid intima-media thickness and C-reactive protein level

Associations between long-term exposure to ambient air pollution and renal function in Southwest China: The China Multi-Ethnic Cohort (CMEC) study

BACKGROUND

Limited studies have examined associations between air pollutants exposure and renal function, especially in China, with the most extensive chronic kidney disease (CKD) disease burden worldwide.

OBJECTIVES

This study examines associations between long-term exposure to ambient PM_2.5, NO₂, CO, O₃, SO₂ and renal function.

METHODS

We included 80,225 participants aged 30-79 years from the baseline data of the China Multi-Ethnic Cohort (CMEC) study. Three-year average concentrations of PM_2.5, NO₂, CO, O₃, and SO₂ were estimated using satellite-based spatiotemporal models. Renal function is determined by the estimated glomerular filtration rate (eGFR) using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. After adjusting for covariates, generalized propensity scores (GPS) weighting regression was used to estimate associations between ambient air pollutants and renal function.

RESULTS

An increase of 0.1 mg/m³ CO (OR [odds ratio] =1.20 95% CI [confidence interval], 1.05-1.37) was positively associated with CKD. An increase of 1 μg/m³ in SO₂ (1.07, 1.00-1.14) concentration was positively associated with CKD. An increase of 10 μg/m³ in PM_2.5 (1.17, 0.99-1.38), NO₂ (1.12, 0.83-1.51) and O₃ (1.10, 0.81-1.50) concentration was not associated with CKD. These effects are stronger in those younger than 65, smoking and with low BMI.

CONCLUSIONS

In this study, we found that long-term exposure to ambient CO and SO₂ were positively associated with CKD. Gaseous pollutants should also arouse the concern of relevant departments.

Long-Term Exposures to Air Pollutants and Risk of Peripheral Arterial Occlusive Disease: A Nationwide Cohort Study in Taiwan

Air pollution is one of the most alarming environmental issues which causes multiple health hazards. An association between air pollution and cardiovascular diseases has been established through many prior studies. In this study, we aimed to evaluate the risk of long-term exposure to air pollution (PM2.5, CO, and NO2) and its association with the risk of developing peripheral arterial occlusive disease (PAOD). PAOD is a condition involving impairment of perfusion of blood in the distal parts of the aorta due to narrowing of the arteries (arterial stenosis) and has been reported as a risk factor for developing cardiovascular diseases. Furthermore, the risk of PAOD increases with age, and hence is a serious public health issue and a cause for concern, especially for an aging society such as Taiwan. Two national-scale databases from Taiwan, the national health insurance database (NHIRD) and the Taiwan air quality-monitoring database (TAQMD), were linked to conduct this cohort study between 2003 and 2013. Cox proportional hazards regression with time-dependent modeling was used to evaluate the hazard ratio (HR) for PAOD with respect to daily exposure to air pollutants. The concentrations of each of the pollutants of interest (PM2.5, NO2, and CO) were categorized into four categories according to the daily average concentration of air pollutants for every quarter of the year, Q1 to Q4 (Q4 = highest). The cumulative incidence of PAOD was examined by Kaplan-Meier analysis with two-tailed log-rank test. A total of 1,598 PAOD cases were identified during the 10-year follow-up period, along with 98,540 non-PAOD controls. In the multivariate analysis, after adjusting for age, gender, urbanization level, residential area, baseline comorbidities, and medications, the adjusted HRs were PM2.5 = 1.14 (95% CI 1.13-1.16), NO2 = 1.03 (95% CI 1.02-1.04), and CO = 2.35 (95% CI 1.95-2.84). Kaplan-Meier analysis showed that CO (P < 0.0001) and PM2.5 (P < 0.0001) concentrations were strongly and positively associated with the cumulative incidence of PAOD during the follow-up period. Findings from this study established that prolonged exposure to air pollutants CO and PM2.5 are significant factors that, among other well-known causes, may also play a potential role in PAOD pathogenesis.

The association of air pollutants exposure with subclinical inflammation and carotid atherosclerosis

BACKGROUND

Air pollution is a well-described environmental factor with evidence suggesting a firm association with cardiovascular diseases. The purpose of this study was to determine the association of exposure to gaseous air pollutants on atherosclerosis burden.

METHODS

1955 inhabitants of the Corinthia region, aged 40 years or older, underwent clinical and biochemical assessment as well as carotid ultrasonography to evaluate carotid intima-media thickness (cIMT) and plaque burden. Analyzers recording time series concentration of CO, NO2, and SO2 were located at 4 different open sites (Regions 1, 2, 3 and 4) based on their proximity to industries, highways or shipyards.

RESULTS

A higher concentration of CO, NO2, and SO2 was observed in Region 4 compared to the other regions. Mean cIMT (Region 1: 0.93 ± 0.24 mm; Region 2: 0.96 ± 0.40 mm; Region 3: 0.94 ± 0.39 mm; Region 4: 1.14 ± 0.55 mm, p < 0.001), maximum cIMT (p < 0.001) as well as carotid plaque burden (Region 1: 13.3%; Region 2: 18.8%; Region 3: 22.4%; Region 4: 38.6%, p < 0.001) were significantly higher in individuals of Region 4. Inhabitants of Region 4 had also higher levels of C reactive protein (Region 1: 4.56 ± 4.85 mg/l; Region 2: 3.49 ± 4.46 mg/l; Region 3: 4.03 ± 3.32 mg/l, Region 4: 5.16 ± 8.26 mg/l, p < 0.001). Propensity score analysis revealed higher inter-area differences in mean cIMT of individuals with coronary artery disease (CAD) (high vs low air pollution area: 1.56 ± 0.80 mm; vs. 1.18 ± 0.54 mm, p < 0.001) while there was no difference in cIMT of the matched population without CAD (p = 0.52).

CONCLUSIONS

An increased carotid atherosclerotic and inflammatory burden is observed in inhabitants of areas with the highest concentration of air pollutants.

Coronary heart disease, hypertension and use of biomass fuel among women: comparative cross-sectional study

OBJECTIVES

To explore the associations of hypertension and coronary heart disease (CHD) with use of biomass fuel for cooking.

DESIGN

Comparative cross-sectional study.

SETTING

Rural villages in Sindh, Pakistan.

PARTICIPANTS

Women aged ≥40 years who had used biomass fuel for cooking for at least the last year (n=436), and a comparison group (n=414) who had cooked only with non-biomass fuel during the last year were recruited through door-to-door visits. None of those who were invited to take part declined.

PRIMARY AND SECONDARY OUTCOME MEASURES

Hypertension was determined from blood pressure measurements and use of medication. CHD was assessed by three measures: history of angina (Rose angina questionnaire), previous history of 'heart attack', and definite or probable changes of CHD on ECG. Potentially confounding risk factors were ascertained by questionnaire and anthropometry. Associations of hypertension and CHD with use of biomass and other risk factors were assessed by logistic regression, and summarised by ORs with 95% CIs.

RESULTS

After adjustment for potential confounders, there was no association of hypertension (OR: 1.0, 95% CI 0.8 to 1.4) angina (OR: 1.0, 95% CI 0.8 to 1.4), heart attack (OR: 1.2, 95% 0.7 to 2.2) or ECG changes of CHD (OR: 0.8, 95% CI 0.6 to 1.2) with current use of biomass for cooking. Nor were any associations apparent when analyses were restricted to long-term (≥10 years) users and non-users of biomass fuel.

CONCLUSIONS

A linked air monitoring study indicated substantially higher airborne concentrations of fine particulate matter in kitchens where biomass was used for cooking. It is possible that associations with CHD and hypertension were missed because most of the comparison group had used biomass for cooking at some time in the past, and risk remains elevated for many years after last exposure.

Association between gaseous air pollutants and inflammatory, hemostatic and lipid markers in a cohort of midlife women

BACKGROUND

Exposures to ambient gaseous pollutants have been linked to cardiovascular diseases (CVDs), but the biological mechanisms remain uncertain.

OBJECTIVES

This study examined the changes in CVD marker levels resulting from elevated exposure to ambient gaseous pollutants in midlife women.

METHODS

Annual repeated measurements of several inflammatory, hemostatic and lipid makers were obtained from 2306 midlife women enrolled in the longitudinal Study of Women's Health Across the Nation (SWAN) between 1999 and 2004. Ambient carbon monoxide (CO), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) data were assigned to each woman based on proximity of the monitoring station to her residential address. Short- and long-term exposures were calculated, and their associations with markers were examined using linear mixed-effects regression models, adjusted for demographic, health and other factors.

RESULTS

Short-term CO exposure was associated with increased fibrinogen, i.e., every interquartile increase of average prior one-week exposure to CO was associated with 1.3% (95% CI: 0.6%, 2.0%) increase in fibrinogen. Long-term exposures to NO₂ and SO₂ were associated with reduced high-density lipoproteins and apolipoprotein A1, e.g., 4.0% (1.7%, 6.3%) and 4.7% (2.8%, 6.6%) decrease per interquartile increment in prior one-year average NO₂ concentration, respectively. Fine particle (PM_2.5) exposure confounded associations between CO/NO₂ and inflammatory/hemostatic markers, while associations with lipoproteins were generally robust to PM_2.5 adjustment.

CONCLUSIONS

Exposures to these gas pollutants at current ambient levels may increase thrombotic potential and disrupt cholesterol metabolism, contributing to greater risk of CVDs in midlife women. Caution should be exercised in evaluating the confounding by PM_2.5 exposure.

Biomass fuel smoke exposure was associated with adverse cardiac remodeling and left ventricular dysfunction in Peru

While household air pollution from biomass fuel combustion has been linked to cardiovascular disease, the effects on cardiac structure and function have not been well described. We sought to determine the association between biomass fuel smoke exposure and cardiac structure and function by transthoracic echocardiography. We identified a random sample of urban and rural residents living in the high-altitude region of Puno, Peru. Daily biomass fuel use was self-reported. Participants underwent transthoracic echocardiography. Multivariable linear regression was used to examine the relationship of biomass fuel use with echocardiographic measures of cardiac structure and function, adjusting for age, sex, height, body mass index, diabetes, physical activity, and tobacco use. One hundred and eighty-seven participants (80 biomass fuel users and 107 non-users) were included in this analysis (mean age 59 years, 58% women). After adjustment, daily exposure to biomass fuel smoke was associated with increased left ventricular internal diastolic diameter (P=.004), left atrial diameter (P=.03), left atrial area (four-chamber) (P=.004) and (two-chamber) (P=.03), septal E' (P=.006), and lateral E' (P=.04). Exposure to biomass fuel smoke was also associated with worse global longitudinal strain in the two-chamber view (P=.01). Daily biomass fuel use was associated with increased left ventricular size and decreased left ventricular systolic function by global longitudinal strain.

Environmental NO2 and CO Exposure: Ignored Factors Associated with Uremic Pruritus in Patients Undergoing Hemodialysis

Uremic pruritus (UP), also known as chronic kidney disease-associated pruritus, is a common and disabling symptom in patients undergoing maintenance hemodialysis (MHD). The pathogenesis of UP is multifactorial and poorly understood. Outdoor air pollution has well-known effects on the health of patients with allergic diseases through an inflammatory process. Air pollution-induced inflammation could occur in the skin and aggravate skin symptoms such as pruritus or impair epidermal barrier function. To assess the role of air pollutants, and other clinical variables on uremic pruritus (UP) in HD patients, we recruited 866 patients on maintenance HD. We analyzed the following variables for association with UP: average previous 12-month and 24-month background concentrations for nitrogen dioxide (NO2) and carbon monoxide (CO), and suspended particulate matter of <2.5 μm (PM2.5). In a multivariate logistic regression, hemodialysis duration, serum ferritin levels, low-density lipoprotein levels, and environmental NO2/CO levels were positively associated with UP, and serum albumin levels were negatively associated with UP. This cross-sectional study showed that air pollutants such as NO2 and CO might be associated with UP in patients with MHD.

Factors related to heart rate variability among firefighters

OBJECTIVES

The aim of this study was to investigate factors associated with heart rate variability in firefighters working in a metropolitan city in South Korea.

METHODS

Self-administered questionnaires including Korean Occupational Stress Scale (KOSS) as well as surveys collecting socio-demographic characteristics and work-related factors were given to 962 firefighters. After exclusion for missing data, 645 firefighters were included, and analysis of covaiance adjusted for the general risk factors and job characteristics were used to assess the relationship between heart rate variability and associated factors.

RESULTS

SDNN and RMSSD and were decreased in the area of occupational climate of the group with high job stress (p = 0.027, p = 0.036). HF(ln) was decreased in the area of organizational system and occupational climate of the group with high stress that statistically significant level (p = 0.034, p = 0.043).

CONCLUSIONS

Occupational climate and organizational system are associated with reduction of heart rate variability. Preventive medical care plans for cardiovascular disease of firefighters through the analysis and evaluation of job stress factors are needed.

Coronary heart disease and household air pollution from use of solid fuel: a systematic review

BACKGROUND

Evidence is emerging that indoor air pollution (IAP) from use of solid fuels for cooking and heating may be an important risk factor for coronary heart disease (CHD).

SOURCES OF DATA

We searched the Ovid Medline, Embase Classic, Embase and Web of Science databases from inception through to June 12, 2015, to identify reports of primary epidemiological research concerning the relationship of CHD to IAP from solid fuel, the likely magnitude of any increase in risk, and potential pathogenic mechanisms.

AREAS OF AGREEMENT

The current balance of epidemiological evidence points to an increased risk of CHD from IAP as a consequence of using solid, and especially biomass, fuels for cooking and heating. Relative risks from long-term exposure could be 2- to 4-fold.

AREAS OF CONTROVERSY

The evidence base is still limited, and although an association of CHD with such IAP from solid fuel is consistent with the known hazards from smoking, environmental tobacco smoke and ambient air pollution, and supported by evidence of effects on inflammatory processes, atherosclerosis and blood pressure, it requires confirmation by larger and more robust studies.

GROWING POINTS

The completion of two relatively small case-control studies on CHD and IAP from use of biomass fuel demonstrates the feasibility of such research, and is an encouragement to further, larger studies using similar methods.

AREAS TIMELY FOR DEVELOPING RESEARCH

The need for such research is particularly pressing because the incidence of CHD in developing countries is rising, and IAP may interact synergistically with the risk factors that are driving that increase. Furthermore, relatively cheap methods are available to reduce IAP from use of solid fuels, and there are indications from intervention studies that these may impact beneficially on CHD as well as other diseases caused by such pollution.

Risk of Peripheral Artery Disease in Patients With Carbon Monoxide Poisoning: A Population-Based Retrospective Cohort Study

Carbon monoxide (CO) poisoning can cause several life-threatening complications, particularly in cardiovascular and neurological systems. However, no studies have been performed to investigate the association between peripheral artery disease (PAD) and CO poisoning. We constructed a population-based retrospective cohort study to clarify the risks between PAD and CO poisoning. This population-based cohort study involved analyzing data from 1998 to 2010 obtained from the Taiwanese National Health Insurance Research Database, with a follow-up period extending to the end of 2011. We identified patients with CO poisoning and selected a comparison cohort that was frequency matched according to age, sex, and year of diagnosis of CO poisoning at a ratio of 1 patient to 4 control patients. We analyzed the risks for patients with CO poisoning and PAD by using Cox proportional hazards regression models. In this study, 9046 patients with CO poisoning and 36,183 controls were included. The overall risks for developing PAD were 1.85-fold in the patients with CO poisoning compared with the comparison cohort after adjusting for age, sex, and comorbidities. Our long-term cohort study results showed a higher risk for PAD development among patients with CO poisoning.

Environmental carbon monoxide level is associated with the level of high-sensitivity C-reactive protein in peritoneal dialysis patients

Inflammation is highly prevalent among peritoneal dialysis (PD) patients. High-sensitivity C-reactive protein (hs-CRP) is the most widely used inflammatory marker in clinical medicine and is correlated with mortality in PD patients. Air pollution is associated with systemic inflammation. The aim of this cross-sectional study was to assess the role of air pollutants and other clinical variables on hs-CRP values in PD patients.We recruited a total of 175 patients who had been undergoing continuous ambulatory PD or automated PD for at least 4 months and regularly followed up. Air pollution levels were recorded by a network of 27 monitoring stations near or in the patients' living areas throughout Taiwan. The 12-month average concentrations of particulate matter (PM) with an aerodynamic diameter of <10 and <2.5 μm (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) were included.In stepwise linear regression, after adjustment for related factors, white blood cell count (β: 0.27, 95% confidence interval [CI] [0.71, 2.11]) and CO level (β: 0.17, 95% CI [2.5, 21.32]) were positively associated with hs-CRP and serum albumin levels (β: -0.25, 95% CI [-13.69, -3.96]) and normalized protein nitrogen appearance (β: -0.18, 95% CI [-17.7, -2.51]) was negatively associated with hs-CRP. However, serum indoxyl sulfate and p-cresyl sulfate levels were not significantly associated with hs-CRP (P > 0.05).In PD patients, the environmental CO level was positively correlated with hs-CRP level.

Occupational stress and subclinical atherosclerosis: a systematic review

BACKGROUND

Stress is a common hazard in the work environment and is associated with multiple adverse health effects. The association between work-related stress (WRS) and cardiovascular disease has been established in a number of epidemiological studies.

METHODS

A systematic review was conducted according to the PRISMA statement of the English literature involving WRS and carotid artery intima media thickness (CIMT).

RESULTS

Four cohorts and six cross-sectional studies of occupational stress and CIMT were identified. All cohorts and five of the cross-sectional studies reported a significant positive association, while one reported an inverse association of WRS and CIMT.

DISCUSSION

The weight of the evidence that we were able to identify suggests that occupational stress results in an increased risk of atherosclerosis, assessed via CIMT. Studies that include longitudinal measures of stress and intermediate cardiac endpoints, with adequate accounting for confounders, are needed. Interventional studies should also be conducted to determine whether CIMT progression can be prevented with workplace stress reduction.

Significance of the carboxyhemoglobin level for out-of-hospital cardiopulmonary arrest

Background:

At low concentrations, carbon monoxide (CO) can confer cyto and tissue-protective effects, such as endogenous Heme oxygenase 1 expression, which has antioxidative, anti-inflammatory, antiproliferative, and antiapoptotic effects. The level of carboxyhemoglobin in the blood is an indicator of the endogenous production of CO and inhaled CO.

Aim of study:

To investigate the significance of the value of carboxyhemoglobin for out-of-hospital (OH) cardiopulmonary arrest (CPA).

Materials and Methods:

This study involved a medical chart review of cases treated from January to December 2005. The inclusion criteria included a patient who was transported to this department due to an OH CPA. The exclusion criteria included a patient who did not undergo blood gas analysis on arrival and who experienced CPA due to acute carbon monoxide intoxication. The subjects were divided into two groups based on their final outcome of either survival or non-survival.

Results:

There was no significant difference associated with the sex, age, frequency of witness collapse, bystander cardiopulmonary arrest, electrocardiogram at scene, cause of CPA, value of PCO₂, HCO₃^-, and methemoglobin. The frequency of OH return of spontaneous circulation and the value of pH, PO₂, base excess, and carboxyhemoglobin in the survival group were greater than those values in the non-survival group. There were no subjects whose carboxyhemoglobin level was 0% on arrival in the survival groups.

Conclusion:

There appeared to be an association between higher carboxyhemoglobin levels and survival in comparison with non-survival patients.

Environmental carbon monoxide related to pregnancy hypertension

Carbon monoxide pollution frequently occurs due to auto exhaust, industrial emissions, and/or cigarette smoke. Exogenous and endogenous carbon monoxide affects blood pressure; however, the relation of carbon monoxide exposure to pregnancy hypertension has not been systematically examined. For the present study the authors recruited a total of 2,707 apparently healthy, non-obese, non-smoking mothers, aged between 15 and 40 years, who had singleton births, and who lived within two miles of the selected air monitoring stations in Tehran, Iran, to study the relation of ambient carbon monoxide to pregnancy hypertension (>140 mmHg systolic and/or >90 mmHg diastolic after the 20th week of gestation). A relatively small but statistically significant elevation in mean postpartum diastolic blood pressure (mean ± SD, 69.5 ± 9.8 mmHg) was observed in the mothers' who were exposed to relatively high ambient carbon monoxide (mean = 14.1 ppm) compared to mothers exposed to lower carbon monoxide (mean = 1.8 ppm) concentrations (mean ± SD, 68.0 ± 8.3 mmHg, p < 0.01). The authors found twice the rate of pregnancy hypertension in the relatively higher carbon monoxide exposed mothers than the mothers with lower exposure (adjusted odds ratio = 2.02, 95% CI 1.35-3.03). Findings of the present study suggest that high level ambient carbon monoxide exposure is associated with pregnancy hypertension.