The association of annual air pollution exposure with blood pressure among patients with sleep-disordered breathing

Long-term associations between ambient air pollution and self-perceived health status: Results from the population-based KORA-Fit study

BACKGROUND

Little is known about the association between air pollution and self-perceived health (including both health-related quality of life [HRQoL] and self-rated health [SRH]). The aim of this study was therefore to explore whether long-term air pollution exposure is associated with worse self-perceived health, as measured by different tools.

METHODS

We used a land-use regression model to determine the annual average levels of particulate matter with a diameter <10 μm (PM10), coarse particles (PMcoarse), fine particles (PM2.5), fine particle absorbances (PM2.5abs), particle number concentration (PNC), ozone (O3), nitrogen dioxide (NO2), and nitrogen oxide (NOX) for geocoded residential addresses (2014-2015). Questionnaires and face-to-face interviews were used to collect HRQoL (measured using the European Quality of Life 5 Dimensions [EQ-5D] index and the European Quality of Life Visual Analogue Scale [EQ-VAS]) and SRH indicators (measured through two survey questions) (2018-2019) from participants of the Cooperative Health Research in the Region of Augsburg (KORA)-Fit study in Germany. We explored associations via generalized additive models, multinomial logistic regression, and logistic regression.

RESULTS

We included 2610 participants with a mean age of 64.0 years in this cross-sectional study, of which 1428 (54.7%) were female. Each interquartile range (IQR) increase in O3 was associated with a reduced EQ-5D index value (% change of mean points and 95% confidence interval: -0.91% [-1.76; -0.06]). The average EQ-VAS score declined between -1.57% and -0.96% with each IQR increase in PM10, PMcoarse, PM2.5abs, PNC, NO2, and NOX. These pollutants were associated with increased occurrence of poor SRH, with odds ratios ranging from 1.24 to 2.67. PM2.5abs was linked to a higher likelihood of reporting a worse comparative SRH (2.59 [1.12; 5.99]). Body mass index and self-perceived stress modified these associations.

CONCLUSIONS

Long-term air pollution exposure was associated with poor self-perceived health, presenting as lower HRQoL and higher odds of poor SRH. Single-item indicators measuring self-perceived health status may work better than multi-dimensional indicators.

Associations between air pollution, intracellular-to-extracellular water distribution, and obstructive sleep apnea manifestations

Background

Exposure to air pollution may be a risk factor for obstructive sleep apnea (OSA) because air pollution may alter body water distribution and aggravate OSA manifestations.

Objectives

This study aimed to investigate the mediating effects of air pollution on the exacerbation of OSA severity through body water distribution.

Methods

This retrospective study analyzed body composition and polysomnographic data collected from a sleep center in Northern Taiwan. Air pollution exposure was estimated using an adjusted nearest method, registered residential addresses, and data from the databases of government air quality motioning stations. Next, regression models were employed to determine the associations between estimated air pollution exposure levels (exposure for 1, 3, 6, and 12 months), OSA manifestations (sleep-disordered breathing indices and respiratory event duration), and body fluid parameters (total body water and body water distribution). The association between air pollution and OSA risk was determined.

Results

Significant associations between OSA manifestations and short-term (1 month) exposure to PM_2.5 and PM₁₀ were identified. Similarly, significant associations were identified among total body water and body water distribution (intracellular-to-extracellular body water distribution), short-term (1 month) exposure to PM_2.5 and PM₁₀, and medium-term (3 months) exposure to PM₁₀. Body water distribution might be a mediator that aggravates OSA manifestations, and short-term exposure to PM_2.5 and PM₁₀ may be a risk factor for OSA.

Conclusion

Because exposure to PM_2.5 and PM₁₀ may be a risk factor for OSA that exacerbates OSA manifestations and exposure to particulate pollutants may affect OSA manifestations or alter body water distribution to affect OSA manifestations, mitigating exposure to particulate pollutants may improve OSA manifestations and reduce the risk of OSA. Furthermore, this study elucidated the potential mechanisms underlying the relationship between air pollution, body fluid parameters, and OSA severity.

Association between long-term exposure to ambient particulate matter and blood pressure, hypertension: an updated systematic review and meta-analysis

Evidence of more recent studies should be updated to evaluate the effect of long-term exposure to particulate matter (PM) on blood pressure and hypertension.        Studies of long-term effects of PM₁, PM_2.5 and PM₁₀ on blood pressure (SBP, DBP, MAP), hypertension were searched in Pubmed, Web of Science and Embase before May, 2021. Meta-analysis of 41 studies showed that exposure to PM₁, PM_2.5 was associated with SBP (1.76 mmHg (95%CI:0.71, 2.80) and 0.63 mmHg (95%CI:0.40, 0.85), per 10 μg/m³ increase in PM), all three air pollutants (PM₁, PM_2.5, PM₁₀) was associated with DBP (1.16 mmHg (95%CI:0.34, 1.99), 0.31 mmHg (95%CI:0.16, 0.47), 1.17 mmHg (95%CI:0.24, 2.09), respectively. As for hypertension, PM₁, PM_2.5 and PM₁₀ were all significantly associated with higher risk of hypertension (OR=1.27 (95%CI:1.06, 1.52), 1.15 (95%CI:1.10, 1.20) and 1.11 (95%CI:1.07, 1.16). In conclusion, our study indicated a positive association between long-term exposure to particulate matter and increased blood pressure, hypertension.

Associations of long-term exposure to air pollution, physical activity with blood pressure and prevalence of hypertension: the China Health and Retirement Longitudinal Study

Background

Long-term exposure to air pollution and physical activity (PA) are linked to blood pressure and hypertension. However, the joint effect of air pollution and PA on blood pressure and hypertension are still unknown in Chinese middle-aged and older adults.

Methods

A total of 14,622 middle-aged and older adults from the China Health and Retirement Longitudinal Study wave 3 were included in this study. Ambient air pollution [particulate matter with diameter ≤ 2.5 μm (PM_2.5), or ≤10 μm (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbonic oxide (CO)] were estimated using satellite-based spatiotemporal models. PA was investigated using International Physical Activity Questionnaire. Generalized linear models were used to examine the associations of air pollution, PA score with blood pressure [systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP)], and the prevalence of hypertension. Subgroup analysis was conducted to investigate the effects of air pollution on blood pressure and the prevalence of hypertension in different PA groups.

Results

The results showed that for each inter-quartile range (IQR) increase in PM_2.5 (25.45 μg/m³), PM₁₀ (40.56 μg/m³), SO₂ (18.61 μg/m³), NO₂ (11.16 μg/m³), CO (0.42 mg/m³) and PA score (161.3 MET/h-week), the adjusted odd ratio (OR) of hypertension was 1.207 (95% confidence interval (CI): 1.137, 1.281), 1.189 (95%CI: 1.122, 1.260), 1.186 (95%CI: 1.112, 1.266), 1.186 (95%CI: 1.116, 1.260), 1.288 (95%CI: 1.223, 1.357), 0.948 (95%CI: 0.899, 0.999), respectively. Long-term exposure to PM_2.5, PM₁₀, SO₂, NO₂, and CO was associated with increased SBP, DBP, and MAP levels. For example, each IQR increase in PM_2.5 was associated with 1.20 mmHg (95%CI: 0.69, 1.72) change in SBP, 0.66 mmHg (95%CI: 0.36, 0.97) change in DBP, and 0.84 mmHg (95%CI: 0.49, 1.19) change in MAP levels, respectively. Each IQR increase in PA score was associated with -0.56 mmHg (95%CI: -1.03, -0.09) change in SBP, -0.32 mmHg (95%CI: -0.59, -0.05) change in DBP, and -0.33 mmHg (95%CI: -0.64, -0.02) change in MAP levels, respectively. Subgroup analysis found that the estimated effects in the sufficient PA group were lower than that in the insufficient PA group.

Conclusion

Long-term exposure to air pollutants is associated with increased blood pressure and hypertension risk, while high-level PA is associated with decreased blood pressure and hypertension risk. Strengthening PA might attenuate the adverse effects of air pollution on blood pressure and hypertension risk.

Association of air pollution exposure with low arousal threshold obstructive sleep apnea: A cross-sectional study in Taipei, Taiwan

Emerging evidence witnesses the association of air pollution exposure with sleep disorders or the risk of obstructive sleep apnea (OSA); however, the results are not consistent. OSA patients with or without a low arousal threshold (LAT) have different pathology and therapeutic schemes. No study has evaluated the potential diverse effects of air pollution on the phenotypes of OSA. The current study aimed to evaluate the associations of short-term and long-term exposure to air pollution with sleep-disordered measures and OSA phenotypes. This cross-sectional study consisted of 4634 participants from a sleep center in Taipei from January 2015 to April 2019. The personal exposure to ambient PM_2.5 and NO₂ was assessed by a spatial-temporal model. Overnight polysomnography was used to measure the sleep parameters. According to a developed clinical tool, we defined the low arousal threshold (LAT) and identified the OSA patients with or without LAT. We applied a generalized linear model and multinomial logistic regression model to estimate the change of sleep measures and risk of the OSA phenotypes, respectively, associated with an interquartile range (IQR) increment of personal pollution exposure after adjusting for the essential confounders. In the single-pollutant model, we observed the associations of NO₂ with sleep-disordered measures by decreasing the total sleep time, sleep efficiency, extending the time of wake after sleep onset, and the association of NO₂ with the increased risk of LAT OSA by around 15%. The two-pollutant model with both long-term and short-term exposures confirmed the most robust associations of long-term NO₂ exposure with sleep measures. An IQR increment of NO₂ averaged over the past year (6.0 ppb) decreased 3.32 min of total sleep time and 0.85% of sleep efficiency. Mitigating exposure to air pollution may improve sleep quality and reduce the risk of LAT OSA.

Short-term ozone exposure and metabolic status in metabolically healthy obese and normal-weight young adults: A viewpoint of inflammatory pathways

Unhealthy metabolic status increases risks of cardiovascular and other diseases. This study aims to explore whether there is a link between O₃ and metabolic health indicators through a viewpoint of inflammatory pathways. 49 metabolically healthy normal-weight (MH-NW) and 39 metabolically healthy obese (MHO) young adults aged 18-26 years were recruited from a panel study with three visits. O₃ exposure were estimated based on fixed-site environmental monitoring data and time-activity diary for each participant. Compared to MH-NW people, MHO people were more susceptible to the adverse effects on metabolic status, including blood pressure, glucose, and lipid indicators when exposed to O₃. For instance, O₃ exposure was associated with significant decreases in high-density lipoprotein cholesterol (HDL-C), and increases in C-peptide and low-density lipoprotein cholesterol (LDL-C) among MHO people, while only weaker changes in HDL-C and LDL-C among MH-NW people. Mediation analyses indicated that leptin mediated the metabolic health effects in both groups, while eosinophils and MCP-1 were also important mediating factors for the MHO people. Although both with a metabolically healthy status, compared to normal-weight people, obese people might be more susceptible to the negative effects of O₃ on metabolic status, possibly through inflammatory indicators such as leptin, eosinophils, and MCP-1.

Association between self-reported snoring and hypertension: a systematic review and meta-analysis

OBJECTIVES

The purpose of this study is to summarize the evidence for the association between snoring and hypertension and the effect of snoring on hypertension in men and/or women.

METHODS

We searched the articles in the Cochrane Library, PubMed, Scopus, Web of Science and Embase published up to 12 November 2020 to evaluate the association between snoring and hypertension. Studies were selected according to the predefined screening criteria and their qualities were assessed by Newcastle-Ottawa Quality Evaluation Scale. The odds ratio and 95% confidence interval were used as effective indicators. It was registered in PROSPERO with the number: CRD42021224912.

RESULTS

According to the inclusion/exclusion criteria, 11 studies including eight prospective cohort studies and three cross-sectional studies were included. The results showed that compared with non-snoring participants, snoring significantly increased the risk of hypertension in both men and women [odds ratio (OR) = 1.32, 95% confidence interval (CI), 1.23-1.42; men: odds ratio (OR) = 1.32; 95% confidence interval (CI), 1.18-1.49; women: odds ratio (OR) = 1.26; 95% confidence interval (CI), 1.14-1.40]. Besides, the risk of hypertension was significantly increased when the snoring frequency was ≥4 nights/week [frequency≥4 nights/week: odds ratio (OR) = 1.42; 95% confidence interval (CI), 1.21-1.66; 4 nights/week >frequency>0: odds ratio (OR) = 1.23; 95% confidence interval (CI),1.13-1.34].

CONCLUSIONS

Snoring is considered as an independent predictor of hypertension in both men and women, which may play a role in the prevention and control of hypertension. People who snore frequently should pay close attention to their blood pressure levels to prevent hypertension.

Impact of short- and long-term exposure to air pollution on blood pressure: A two-decade population-based study in Tehran

Plenty of recent studies on the impact of air pollution on blood pressure (BP) exist; however, there is a lack of data for the highly polluted Eastern Mediterranean region. We evaluated the associations of short-term exposure to air pollutants with systolic BP (SBP) and diastolic BP (DBP) and the long-term impact of air pollutants on incident hypertension, among Tehranian adults. In the Tehran Lipid and Glucose Study, 4580 nonhypertensive participants aged 20-69 years (41.6% male) were followed from 2001 to 2018 through 3-year follow-ups and 4-5 examinations of them were recorded. The air pollutants included particulate matter with a diameter ≤10 μm (PM₁₀), carbon monoxide (CO), ozone (O₃), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂). The mixed-effects transition model estimated the air pollution impact on BP. The proportional hazards Weibull model measured the long-term effects of air pollutants on the multivariate hazard of incident hypertension. The air pollutants were put in the models in the form of mean annual level, applying three versions of 1, 2, and 3 years before the follow-ups. During a median follow-up of 12.3 years, 1618 cases of hypertension were found. In the short-term, increase in CO did not affect SBP but decreased DBP with a delay effect lasting for 14 days; increase in NO₂ raised SBP with a 14-day lag, however did not change DBP; increase in O₃ reduced SBP with a 14-day lag but made slight non-significant increase in DBP; rise in PM₁₀ concentrations led to increased SBP (lag 0-3 days) and DBP with lags of 0-3 days and 12-14 days and increase in SO₂ made the largest increases in DBP with lags lasting for 14 days, but did not affect SBP. Regarding incident hypertension in the long-term, the increase in CO had no significant effect; increase in NO₂ decreased the risk over the 2- and 3-year time spans; rise in O₃, PM₁₀, and SO₂ levels increased the risk in all time spans; the largest hazard ratio [1.96 (95% CI: 1.48, 2.62)] for incident hypertension was attributable to PM₁₀ in 3 years. Considering the major effects of air pollutants including O₃, SO₂, and especially PM₁₀ on incident hypertension, urgent public health policies should be implemented to reduce the burden of air pollution in metropolitan city of Tehran.

The effect of weather, air pollution and seasonality on the number of patient visits for epileptic seizures: A population-based time-series study

OBJECTIVE

The objective of the study was to explore the influences of seasonality, meteorological conditions, and air pollution exposure on the number of patients who visit the hospital due to seizures.

METHODS

Outpatient and inpatient data from the National Health Insurance Database of Taiwan from 2009 to 2013, meteorological data from the Meteorological Bureau, and air pollution exposure data from the Taiwan Air Quality Monitoring Stations were collected and integrated into daily time series data. The following data processing and analysis results are based on the mean of the 7 days' lag data of the 18 meteorological condition/air pollution exploratory factors to identify the critical meteorological conditions and air pollution exposure factors by executing univariate analysis. The average hospital visits for seizure per day by month were used as an index of observation. The effect of seasonality has also been examined.

RESULTS

The average visits per day by month had a significant association with 10 variables. Overall, the number of visits due to these factors has been estimated to be 71.529 (13.7%). The most obvious factors affecting the estimated number of visits include ambient temperature, CH₄, and NO. Six air pollutants, namely CH₄, NO, CO, NO₂, PM2.5, and NMHC had a significantly positive correlation with hospital visits due to seizures. Moreover, the average daily number of hospital visits was significantly high in January and February (winter season in Taiwan) than in other months (R² = 0.422).

CONCLUSION

The prediction model obtained in this study indicates the necessity of rigorous monitoring and early warning of these air pollutants and climate changes by governments. Additionally, the study provided a firm basis for establishing prediction models to be used by other countries or for other diseases.

Ambient air pollutants aggravate association of snoring with prevalent hypertension: results from the Henan Rural Cohort

AIM

We aimed to assess if snoring and ambient air pollutants were jointly associated with prevalent hypertension in a cross-sectional study.

METHODS

A total of 28440 participants aged 18-79 years were obtained from the Henan Rural Cohort. Snoring evaluated using Pittsburgh sleep quality index (PSQI) scale was classified into 'Never', '<3 times/week' and '≥3 times/week' groups. Concentrations of air pollutants (PM1, PM2.5, PM10, and NO2) were evaluated by a satellite-based spatiotemporal model. The independent and joint associations between snoring and air pollutants on prevalence of hypertension were analyzed by logistic regression models.

RESULTS

The mean age of all participants was 56.0 ± 12.2 years. The frequencies and prevalence of participants with hypertension were 3666 (32.39%) in men and 5576(32.57%) in women, respectively. The odds ratio (OR) and 95% confidence interval (CI) of participants with snoring frequency of <3 times/week, ≥3 times/week was 1.10(1.02-1.20), and 1.15(1.08-1.23) for hypertension, compared to those without snoring. Participants with a snoring (≥3 times/week) and higher exposure concentrations of PM1, PM2.5, PM10, and NO2 had 2.58-fold(95% CI: 2.30-2.90), 3.03-fold(95% CI: 2.69-3.41), 2.89-fold(95% CI: 2.57-3.25) and 2.75-fold(95% CI: 2.44-3.10) for hypertension, compared to those without snoring and low concentrations of air pollutants. Additionally, participants with high PM1 and ≥3 times/week snoring (OR: 1.32, 95% CI: 1.18-1.48) was at a higher likelihood for prevalent hypertension, compared to those without snoring and with high PM1.

CONCLUSIONS

Snoring and high ambient air pollutants might be important predictors of hypertension, and higher concentration of PM1 might aggravate the association between snoring and hypertension.

Toxicological screening of airborne particulate matter in atmosphere of Pune: Reactive oxygen species and cellular toxicity

Present study screened the toxicological assessment of airborne particulate matter (PM), mechanistic investigation, relationship between the physicochemical characteristics and its associated toxic response. The average concentration of both PM₁₀ and PM_2.5 exceeded the Indian National Ambient Air Quality Standards. In present study, PM bound metals; Fe, Cu, Cr, Ni, Mn, Pb, Cd, Zn, Sr and Co have been taken into account with total metal concentration of 0.83 and 0.44 μg m^-3 of PM₁₀ and PM_2.5 mass concentrations, respectively. The contribution of redox active metals (Fe, Cu, Cr, Ni and Mn) in PM was more as compared to non-redox metals (Pb, Cd and Co) indicating significant risk to the exposed population as these metals possess the ability to produce reactive oxygen species (ROS) which are responsible for various diseases. The cytotoxicity profiles of PM samples determined by MTT assay on two different cell lines (A549 and PBMC) exhibited dose-dependent effects after 24 h exposure, but the consequences differ with respect to particle size and sampling periods. A significant decrease in cell viability with varying PM concentrations (20, 40, 60, 80 and 100 μg ml^-1) with respect to control was found in both cell lines. Incubation of RBC suspension with PM samples caused pronounced disruption of RBC and thus exhibited substantial hemolytic behavior. PM samples showed a range of potency to produce reactive oxygen species (ROS). Almost all PM samples increased the level of pro-inflammatory mediator (Nitric oxide) when compared to corresponding unexposed controls suggesting the important role of reactive nitrogen species in induction of cellular toxicity.

Do the levels of particulate matters less than 10 μm and seasons affect sleep?

Background: There are few studies showing that the increase in particulate matters less than 10 μm (PM10) values increases the apnea-hypopnea index (AHI). We aimed to investigate relationship between air quality parameters and the seasons with the AHI.Methods: This was a retrospective study that included 500 adults. Polysomnography (PSG) was performed on all patients. Oxygen saturation, air temperature, relative humidity, and PM10 values were recorded in Düzce for every year. The parameters of the national air quality network and sleep parameters of 500 individuals hospitalized between 2015 and 2017 were checked.Results: A total of 500 patients were included in the study, of whom 316 (63.2%) were male and 184 (36.8%) were female. While the AHI value of patients who presented during 2016 was 27.5, it had significantly declined to 20.2 in 2017 (p = .024). A significant decline was observed in AHI values of OSA patients from 2016 to 2017 (p = .043). A significant positive correlation was observed between REM-related AHI and relative humidity (r  =  0.183, p = .002). Conclusions: This study showed a clear relationship between AHI and PM10 during winter when air pollution parameters are high in the region. PM10 emerged as a parameter that substantially increases the relative risk for OSA.

Air Pollutants Are Associated With Obstructive Sleep Apnea Severity in Non-Rapid Eye Movement Sleep

STUDY OBJECTIVES

The relationship between seasonal variation of obstructive sleep apnea and ambient temperature and pollutants has been inconsistent in previous studies. It is also unknown whether the seasonal variation in apnea-hypopnea index influences continuous positive airway pressure treatment dose. This study aims to examine the seasonality of obstructive sleep apnea and continuous positive airway pressure treatment, and the association between air pollutants and apnea-hypopnea index in adults with different sleep apnea severity during different sleep stages.

METHODS

Polysomnography of 5,413 patients referred to one sleep center during 2008-2015 were examined retrospectively. Ambient conditions and air pollutants levels were collected from the official air condition surveillance database. Cosinor analysis was used to examine seasonal variances. The general linear model was used to examine associations between air conditions and apnea-hypopnea index adjusted for seasonality. Models for apnea-hypopnea index in different sleep stages, sex groups, and obstructive sleep apnea severity groups were analyzed separately.

RESULTS

Seasonal variations for continuous positive airway pressure treatment were not significant. Particulate matter less than or equal to 10 μm, ozone, sulfur dioxide, and relative humidity were associated with apnea-hypopnea index only in patients with severe obstructive sleep apnea. The association was significant only in non-rapid eye movement sleep.

CONCLUSIONS

An adjustment for continuous positive airway treatment dose by season is not warranted. Protection for air pollutant-vulnerable groups should be provided. The exact mechanism of the associations between apnea-hypopnea index and air conditions only in non-rapid eye movement sleep must be clarified.

Association between air pollution and sleep disordered breathing in children

BACKGROUND AND OBJECTIVE

Similar to other respiratory diseases, sleep disordered breathing (SDB) may be exacerbated by air contaminants. Air pollution may have an impact on incidence and severity of SDB in children. The aims of this study were to examine potential associations between the exposure to different air pollutants and SDB symptoms in children.

METHODS

In this cross-sectional study, parents from first grade children of elementary schools throughout Chile were included. Data about clinical and family-related SDB risk factors, and the pediatric sleep questionnaire (PSQ) were obtained. Air pollution and meteorological data were obtained from the Chilean online air quality database.

RESULTS

A total of 564 children (44.9% males) aged (median) 6 years (5-9 year) were included. Prevalence of SDB based on PSQ was 17.7%. When examining air pollutants and conditions, only higher humidity (β = 0.005, 95%CI 0.001-0.009, P = 0.011) was significantly associated with higher PSQ scores after adjusting for demographic and household variables. Higher ozone (O₃ ) levels (OR = 1.693, 95%CI 1.409-2.035, P < 0.001), higher humidity (OR = 1.161, 95%CI 1.041-2.035, P = 0.008) and higher dioxide sulfur (SO₂ ) levels (OR = 1.16, 95%CI 1.07-1.94, P < 0.001]) were associated with increased odds of wheezing-related sleep disturbances after adjusting for confounders. Lower temperature was a significant predictor of snoring at least >3 nights/week, following adjustment (OR = 0.865, 95%CI 0.751-0.997, P < 0.05).

CONCLUSION

Sleep respiratory symptoms (wheezing and snoring) are significantly associated with air pollutants such as O₃ and SO₂ . In addition, meteorological conditions such as humidity and low temperatures may be also associated with SDB-related symptoms.

Global association between ambient air pollution and blood pressure: A systematic review and meta-analysis

Although numerous studies have investigated the association of ambient air pollution with hypertension and blood pressure (BP), the results were inconsistent. We performed a comprehensive systematic review and meta-analysis of these studies. Seven international and Chinese databases were searched for studies examining the associations of particulate (diameter<2.5 μm (PM_2.5), 2.5-10 μm (PM_2.5-10) or >10 μm (PM₁₀)) and gaseous (sulfur dioxide (SO₂), nitrogen dioxide (NO₂), nitrogen oxides (NO_x), ozone (O₃), carbon monoxide (CO)) air pollutants with hypertension or BP. Odds ratios (OR), regression coefficients (β) and their 95% confidence intervals were calculated to evaluate the strength of the associations. Subgroup analysis, sensitivity analysis, and meta-regression analysis were also conducted. The overall meta-analysis showed significant associations of long-term exposures to PM_2.5 with hypertension (OR = 1.05), and of PM₁₀, PM_2.5, and NO₂ with DBP (β values: 0.47-0.86 mmHg). In addition, short-term exposures to four (PM₁₀, PM_2.5, SO₂, NO₂), two (PM_2.5 and SO₂), and four air pollutants (PM₁₀, PM_2.5, SO₂, and NO₂), were significantly associated with hypertension (ORs: 1.05-1.10), SBP (β values: 0.53-0.75 mmHg) and DBP (β values: 0.15-0.64 mmHg), respectively. Stratified analyses showed a generally stronger relationship among studies of men, Asians, North Americans, and areas with higher air pollutant levels. In conclusion, our study indicates a positive association between ambient air pollution and increased BP and hypertension. Geographical and socio-demographic factors may modify the pro-hypertensive effects of air pollutants.

Sleep Apnea Morbidity: A Consequence of Microbial-Immune Cross-Talk?

OSA has emerged as a highly prevalent public health problem that imposes important mid- and long-term consequences, namely cardiovascular, metabolic, cognitive, and cancer-related alterations. OSA is characterized by increased upper airway resistance, alveolar hypoventilation, and recurrent upper airway obstruction during sleep. Recurrent collapse of the upper airway develops with sleep onset and is associated with both intermittent hypoxemia and sleep fragmentation. The microbiome is a vast and complex polymicrobial ecosystem that coexists with the human organism, and it has been identified as playing significant roles in the development of host immunologic phenotypes. In humans and animal models, changes in gut microbial communities occur with lifestyle behaviors, such as smoking, long-distance travel, dietary preferences, physical exercise, and circadian rhythm disturbances. In parallel, diseases previously attributed in part to lifestyle such as obesity, coronary heart disease, depression, and asthma (also associated with OSA) are now claimed as microbiota related. We therefore posit that altered patterns of sleep and oxygenation, as seen in OSA, will promote specific alterations in gut microbiota that in turn will elicit the immunologic alterations that lead to OSA-induced end-organ morbidities. The present article assesses the potential mechanistic links between OSA-induced changes in gut microbiota and its morbid phenotypes.

A clean environmental week: Let the nature breathe

High levels of CO₂ emissions in the atmosphere and toxic pollutants in air, water and food have serious repercussions on all life's systems, including living beings, environment and economy. Everyone on the Earth is concerned by pollution in some way or another, no matter where and how the pollution is produced as airborne and foodborne pollutants could circulate around the world in different ways, through for example climate components (wind, rain) and/or import and export of foodstuffs. Similarly to living beings that take advantage of day-night circadian rhythms to recover after diurnal hardships, the environment in its entirety could also be seen as a complex living system that needs regular breaks to assimilate or ingest toxic pollutants produced during intensive and continuous industrial processes. If greenhouses gas emissions and pollution rates continue to increase at the same rates as they are nowadays, uncontrollable climate effects might be inevitable and the air quality in some crowded cities in the world might be hardly respirable in the future. A global "Clean Environmental Week" is discussed as an attempt toward reducing air pollution and CO₂ emissions through the interruption or reduction of industrial polluting activities regularly, for a week or so per year, to let the nature 'breathe' and recover from environmentally challenging pollutions. A clean environmental period of 10 days per year could reduce CO₂ emissions by about one billion tons of CO₂ per annum.

Urban air quality, meteorology and traffic linkages: Evidence from a sixteen-day particulate matter pollution event in December 2015, Beijing

A heavy 16-day pollution episode occurred in Beijing from December 19, 2015 to January 3, 2016. The mean daily AQI and PM_2.5 were 240.44 and 203.6μg/m³. We analyzed the spatiotemporal characteristics of air pollutants, meteorology and road space speed during this period, then extended to reveal the combined effects of traffic restrictions and meteorology on urban air quality with observational data and a multivariate mutual information model. Results of spatiotemporal analysis showed that five pollution stages were identified with remarkable variation patterns based on evolution of PM_2.5 concentration and weather conditions. Southern sites (DX, YDM and DS) experienced heavier pollution than northern ones (DL, CP and WL). Stage P2 exhibited combined functions of meteorology and traffic restrictions which were delayed peak-clipping effects on PM_2.5. Mutual information values of Air quality-Traffic-Meteorology (ATM-MI) revealed that additive functions of traffic restrictions, suitable relative humidity and temperature were more effective on the removal of fine particles and CO than NO₂.

Indoor/outdoor not-voluptuary-habit pollution and sleep-disordered breathing in children: a systematic review

BACKGROUND

Exposure to environmental pollutants is advocated to be a major risk factor, with increased morbidity and mortality in humans due to acute and chronic airway inflammation. The aim of the present review is to show the literature research regarding the link between the sleep-disordered breathing and exposure to indoor/outdoor pollution in children. We hypothesized that environmental air pollution can play a role in childhood sleep-disordered breathing.

METHODS

We conducted an electronic search in Medline (with PubMed interface), Scopus and the ISI Web of Science using the keywords "sleep" or "sleep apnea" or "sleep disordered breathing" and "pollution" and "children" in "Title/Abstract/Keywords", with language restriction (non-English paper) and no date limitation to present. The tobacco smoke pollution is well established linking and is not considered for the present subject. We examined the strength of the evidence according to the Oxford Centre for Evidence-Based Medicine [2011] and the Centre for Evidence-Based Medicine [2009].

RESULTS

A total of 105 articles were identified, but 97 of these had to be excluded after an accurate reading of the title, abstract or full text. In the end, eight studies were selected for our analysis for a total of a total of 5,826 children. The results suggest an involvement (grade C) of environmental (not from voluptuary habits) pollution in the worsening of sleep-disordered breathing in children.

CONCLUSIONS

To date, some studies reported significant differences between areas with higher and lower pollutants and the interventions on indoor pollution reduced sleep-disordered breathing in children. Therefore, although the relevance of the argument is high, the number of studies and the interest in the subject seems at this time quite limited.

Long-Term Exposure to Particulate Matter and Self-Reported Hypertension: A Prospective Analysis in the Nurses' Health Study

BACKGROUND

Studies have suggested associations between elevated blood pressure and short-term air pollution exposures, but the evidence is mixed regarding long-term exposures on incidence of hypertension.

OBJECTIVES

We examined the association of hypertension incidence with long-term residential exposures to ambient particulate matter (PM) and residential distance to roadway.

METHODS

We estimated 24-month and cumulative average exposures to PM10, PM2.5, and PM2.5-10 and residential distance to road for women participating in the prospective nationwide Nurses' Health Study. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for incident hypertension from 1988 to 2008 using Cox proportional hazards models adjusted for potential confounders. We considered effect modification by age, diet, diabetes, obesity, region, and latitude.

RESULTS

Among 74,880 participants, 36,812 incident cases of hypertension were observed during 960,041 person-years. In multivariable models, 10-μg/m3 increases in 24-month average PM10, PM2.5, and PM2.5-10 were associated with small increases in the incidence of hypertension (HR: 1.02, 95% CI: 1.00, 1.04; HR: 1.04, 95% CI: 1.00, 1.07; and HR: 1.03, 95% CI: 1.00, 1.07, respectively). Associations were stronger among women < 65 years of age (HR: 1.04, 95% CI: 1.01, 1.06; HR: 1.07, 95% CI: 1.02, 1.12; and HR: 1.05, 95% CI: 1.01, 1.09, respectively) and the obese (HR: 1.07, 95% CI: 1.04, 1.12; HR: 1.15, 95% CI: 1.07, 1.23; and HR: 1.13, 95% CI: 1.07, 1.19, respectively), with p-values for interaction < 0.05 for all models except age and PM2.5-10. There was no association with roadway proximity.

CONCLUSIONS

Long-term exposure to particulate matter was associated with small increases in risk of incident hypertension, particularly among younger women and the obese.

CITATION

Zhang Z, Laden F, Forman JP, Hart JE. 2016. Long-term exposure to particulate matter and self-reported hypertension: a prospective analysis in the Nurses' Health Study. Environ Health Perspect 124:1414-1420; http://dx.doi.org/10.1289/EHP163.