Physical Activity, Air Pollution, and the Risk of Asthma and Chronic Obstructive Pulmonary Disease

Health Benefits of Different Sports: a Systematic Review and Meta-Analysis of Longitudinal and Intervention Studies Including 2.6 Million Adult Participants

BACKGROUND

Several reviews have examined the health benefits of participation in specific sports, such as baseball, cricket, cross-country skiing, cycling, downhill skiing, football, golf, judo, rugby, running and swimming. However, new primary studies on the topic have recently been published, and the respective meta-analytic evidence needs to be updated.

OBJECTIVES

To systematically review, summarise and appraise evidence on physical health benefits of participation in different recreational sports.

METHODS

Searches for journal articles were conducted in PubMed/MEDLINE, Scopus, SpoLit, SPORTDiscus, Sports Medicine & Education Index and Web of Science. We included longitudinal and intervention studies investigating physical health outcomes associated with participation in a given sport among generally healthy adults without disability.

RESULTS

A total of 136 papers from 76 studies conducted among 2.6 million participants were included in the review. Our meta-analyses of available evidence found that: (1) cycling reduces the risk of coronary heart disease by 16% (pooled hazard ratio [HR] = 0.84; 95% confidence interval [CI]: 0.80, 0.89), all-cause mortality by 21% (HR = 0.79; 95% CI: 0.73, 0.84), cancer mortality by 10% (HR = 0.90; 95% CI: 0.85, 0.96) and cardiovascular mortality by 20% (HR = 0.80; 95% CI: 0.74, 0.86); (2) football has favourable effects on body composition, blood lipids, fasting blood glucose, blood pressure, cardiovascular function at rest, cardiorespiratory fitness and bone strength (p < 0.050); (3) handball has favourable effects on body composition and cardiorespiratory fitness (p < 0.050); (4) running reduces the risk of all-cause mortality by 23% (HR = 0.77; 95% CI: 0.70, 0.85), cancer mortality by 20% (HR = 0.80; 95% CI: 0.72, 0.89) and cardiovascular mortality by 27% (HR = 0.73; 95% CI: 0.57, 0.94) and improves body composition, cardiovascular function at rest and cardiorespiratory fitness (p < 0.010); and (5) swimming reduces the risk of all-cause mortality by 24% (HR = 0.76; 95% CI: 0.63, 0.92) and improves body composition and blood lipids (p < 0.010).

CONCLUSIONS

A range of physical health benefits are associated with participation in recreational cycling, football, handball, running and swimming. More studies are needed to enable meta-analyses of health benefits of participation in other sports. PROSPERO registration number CRD42021234839.

Physical activity attenuates the association of long-term exposure to nitrogen dioxide with sleep quality and its dimensions in Chinese rural older adults

BACKGROUND

Joint impacts of air pollution and physical activity (PA) on sleep quality remain unaddressed. We aimed to investigate whether PA attenuates the association of long-term exposure to nitrogen dioxide (NO2) with sleep quality and its dimensions in older adults.

METHODS

This study included 3408 Chinese rural older adults. Annual NO2 was estimated using the Space-Time Extra-Trees model. PA was assessed by International Physical Activity Questionnaire. Sleep quality was evaluated using Pittsburgh Sleep Quality Index (PSQI) scale. Linear regression models were used to assess the associations of long-term NO2 exposure and PA with sleep quality and its dimensions, and interaction plots were used to depict the attenuating effect of PA on associations of NO2 with sleep quality and its dimensions.

RESULTS

Three-year (3-y) average NO2 (per 0.64-μg/m3 increment) was positively associated with global PSQI (β = 0.41, 95 % CI: 0.23, 0.59), sleep duration (β = 0.16, 95 % CI: 0.11, 0.21), and habitual sleep efficiency (β = 0.22, 95 % CI: 0.17, 0.27), while PA was negatively associated with global PSQI (β = -0.33, 95 % CI: -0.46, -0.20) and five domains of PSQI other than sleep duration and sleep disturbances. The associations of NO2 with global PSQI, sleep duration, and habitual sleep efficiency were attenuated with increased PA (Pinteraction were 0.037, 0.020, and 0.079, respectively).

CONCLUSIONS

PA attenuates the adverse impacts of long-term NO2 exposure on sleep quality, especially on sleep duration, and habitual sleep efficiency, in Chinese rural elderly people. Participating in PA should be encouraged in this population, and continued efforts are still needed to reduce air pollution.

Shaping urban environments to improve respiratory health: recommendations for research, planning, and policy

Urban areas carry a large burden of acute (infectious) and chronic respiratory diseases due to environmental conditions such as high levels of air pollution and high population densities. Car-dominated cities often lack walkable areas, which reduces opportunities for physical activity that are fundamentally important for healthy lungs. The already restricted amount of green space available-with often poorly selected plants-could produce pollen and subsequently provoke or worsen allergic diseases. Less affluent neighbourhoods often carry a larger respiratory disease burden. A multisectoral approach with more diverse policy measures and urban innovations is needed to reduce air pollution (eg, low emission zones), to increase public space for walking and cycling (eg, low traffic neighbourhoods, superblocks, 15-minute cities, and car-free cities), and to develop green cities (eg, planting of low-allergy trees). Stricter EU air quality guidelines can push these transformations to improve the respiratory health of citizens. Advocacy by medical respiratory societies can also make an important contribution to such changes.

Life's Essential 8, genetic predisposition, and risk of incident adult-onset asthma: a prospective cohort study

BACKGROUND

Adult-onset asthma (AOA) and cardiovascular diseases shared common risk factors and similar pathophysiologic resemblances. The American Heart Association (AHA) unveiled the life's essential 8 (LE8) to promote cardiovascular health (CVH). This study aimed to assess the overall impact of LE8 implementation on AOA prevention.

METHODS

According to the guideline of AHA's Construct of CVH in 2022, LE8 score was calculated from 8 health status concerning diet, physical activity, nicotine exposure, sleep health, body mass index, blood lipids, blood glucose, and blood pressure. Cox proportional-hazards models were used to estimate effect sizes of associations between CVH, asthma genetic risk, and risk of incident AOA in participants selected from the UK Biobank study.

RESULTS

A total of 6180 incident AOA cases occurred in 249,713 participants during an average of 11.60 y' follow-up. A higher LE8 score was associated with a lower risk of incident AOA with a significant linear trend (P < 0.0001). Every standard deviation increment of LE8 was associated with a 17% (HR: 0.83; 95% CI: 0.81, 0.85) lower risk of incident AOA. Compared with participants with low-CVH score, participants with moderate (HR: 0.72; 95% CI: 0.67, 0.78) and high CVH scores (HR: 0.52; 95% CI: 0.47, 0.58) were associated with a lower risk of incident AOA (P-trend < 0.0001). No significant multiplicative or additive interaction was found between LE8 score and genetic risks. Stratified analysis showed a consistent association between CVH and risk of incident AOA across different asthma polygenic risk score (PRS) levels. Compared with participants with high PRS and low CVH, participants with low PRS and high CVH experienced the lowest risk (HR: 0.28; 95% CI: 0.23, 0.34) of incident AOA.

CONCLUSIONS

Our findings suggest that maintaining optimal CVH should be recommended as a preventive strategy for AOA, regardless of their asthma genetic risks.

Associations of long-term exposure to air pollution and physical activity with the risk of systemic inflammation-induced multimorbidity in Chinese adults: results from the China multi-ethnic cohort study (CMEC)

OBJECTIVE

Previous studies proved the effect of long-term exposure to air pollution or physical activity (PA) on the risk of systemic inflammation-induced multimorbidity (SIIM), while the evidence regarding their joint effects was rare, especially in low- and middle-income countries. Therefore, we aimed to examine the extent of interaction or joint relations of PA and air pollution with SIIM.

METHODS

This study included 72,172 participants from China Multi-Ethnic Cohort.The average concentrations of ambient particulate matter pollutants (PM1, PM2.5, and PM10) were estimated using satellite-based random forest models. Self-reported information on a range of physical activities related to occupation, housework, commuting, and leisure activities was collected by an interviewer-administered questionnaire. A total of 11 chronic inflammatory systemic diseases were assessed based on self-reported lifetime diagnosis or medical examinations. SIIM was defined as having ≥ 2 chronic diseases related to systemic inflammation. Logistic regression models were used to assess the complex associations of air pollution particulate matter and PA with SIIM.

RESULTS

We found positive associations between long-term air pollution particulates exposure and SIIM, with odds ratios (95%CI) of 1.07 (1.03 to 1.11), 1.18 (1.13 to 1.24), and 1.08 (1.05 to 1.12) per 10 µg/m3 increase in PM1, PM2.5, and PM10. No significant multiplicative interaction was found between ambient air pollutant exposure and PA on SIIM, whereas negative additive interaction was observed between long-term exposure to PM2.5 and PA on SIIM. The positive associations between low volume PA and SIIM were stronger among those exposed to high-level air pollution particulates. Compared with individuals engaged in high volume PA and exposed to low-level ambient air pollutants, those engaged in low volume PA and exposed to high-level ambient air pollutants had a higher risk of SIIM (OR = 1.49 in PM1 exposure, OR = 1.84 in PM2.5 exposure, OR = 1.19 in PM10 exposure).

CONCLUSIONS

Long-term (3 years average) exposure to PM1, PM2.5, and PM10 was associated with an increased risk of SIIM. The associations were modified by PA, highlighting PA's importance in reducing SIIM for all people, especially those living in high-level air pollution regions.

The impact of air pollution on asthma: clinical outcomes, current epidemiology, and health disparities

INTRODUCTION

Air pollution has been shown to have a significant impact on morbidity and mortality of respiratory illnesses including asthma.

AREAS COVERED

Outdoor air pollution consists of a mixture of individual pollutants including vehicle traffic and industrial pollution. Studies have implicated an array of individual components of air pollution, with PM2.5, NO2, SO2, and ozone being the most classically described, and newer literature implicating other pollutants such as black carbon and volatile organic compounds. Epidemiological and cohort studies have described incidence and prevalence of pollution-related asthma and investigated both acute and chronic air pollution exposure as they relate to asthma outcomes. There is an increasing body of literature tying disparities in pollution exposure to clinical outcomes. In this narrative review, we assessed the published research investigating the association of pollution with asthma outcomes, focusing on the adult population and health care disparities.

EXPERT OPINION

Pollution has multiple deleterious effects on respiratory health but there is a lack of data on individualized pollution monitoring, making it difficult to establish a temporal relationship between exposure and symptoms, thereby limiting our understanding of safe exposure levels. Future research should focus on more personalized monitoring and treatment plans for mitigating exposure.

Long-term air pollution exposure, habitual physical activity, and incident chronic kidney disease

Both air pollution and physical inactivity contribute to the increased risk of incident chronic kidney disease (CKD). However, the detrimental effects of air pollution exposure could be augmented by an elevated intake of air pollutants during exercise. In the present study, we analyzed 367,978 participants who were CKD-free at baseline (2006-2010) based on the UK Biobank. Air pollutants included fine particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and nitrogen oxides (NOX). Physical activity (PA) was obtained by the self-reported questionnaire. Using Cox proportional hazards models, hazard ratios (HRs) for incident CKD related to air pollution, PA, and incident CKD were evaluated. During a median of 12.4 years of follow-up, 14,191 incident CKD events were documented. High PM2.5, PM10, NO2, and NOX increased CKD risks by 11 %, 15 %, 14 %, and 12 %, respectively, while moderate and high PA reduced CKD risks by 18 % and 22 %, respectively. Participants with high PA and low air pollution exposure had 29 %, 31 %, 30 %, and 30 % risks of incident CKD than those with low PA and high air pollution exposure for the four air pollutants, with multivariable-adjusted HRs of 0.71 (95 % confidence intervals [CI]: 0.65-0.76) for PM2.5, 0.69 (95 % CI: 0.64-0.75) for PM10, 0.70 (95 % CI: 0.64-0.75) for NO2, and 0.70 (95 % CI: 0.64-0.75) for NOX. No clear interactions were observed between each air pollutant exposure and PA (all P for interaction > 0.05). The findings that reducing air pollution exposure and increasing PA were both independently correlated with a diminished risk of incident CKD suggest that PA could be targeted to prevent CKD generally regardless of air pollution levels. Further research is needed in areas polluted moderately and severely to examine our findings.

Modulation of the Cardiovascular Effects of Polycyclic Aromatic Hydrocarbons: Physical Exercise as a Protective Strategy

Exposure to polycyclic aromatic hydrocarbons (PAHs) present in air pollution increases cardiovascular risk. On the contrary, physical exercise is a widely used therapeutic approach to mitigate cardiovascular risk, but its efficacy in an environment of air pollution, particularly with PAHs, remains unclear. This study investigates the effects of exercise on inflammation, endothelial dysfunction, and REDOX imbalance due to PAH exposure using a mouse model. Twenty male BALB/c mice were subjected to a mixture of PAHs (phenanthrene, fluoranthene, pyrene) in conjunction with aerobic exercise. The investigation evaluated serum levels of inflammatory cytokines, gene expression linked to inflammatory markers, endothelial dysfunction, and REDOX imbalance in aortic tissues. Furthermore, the study evaluated the expression of the ICAM-1 and VCAM-1 proteins. Exercise led to notable changes in serum inflammatory cytokines, as well as the modulation of genes associated with endothelial dysfunction and REDOX imbalance in aortic tissue. In turn, exercise produced a modulation in the protein expression of ICAM-1 and VCAM-1. The findings implicate the potential of exercise to counter PAH-induced damage, as demonstrated by changes in markers. In conclusion, exercise could mitigate the adverse effects related to exposure to PAHs present in air pollution, as evidenced by changes in inflammatory markers, endothelial dysfunction, and REDOX imbalance.

Association Between the Combined Effects of Physical Activity Intensity and Particulate Matter and All-Cause Mortality in Older Adults

OBJECTIVE

To investigate the association between the combined effects of physical activity (PA) intensity and particulate matter ≤10 μm in diameter (PM10) and mortality in older adults.

METHODS

This nationwide cohort study included older adults without chronic heart or lung disease who engaged in regular PA. Physical activity was assessed by a standardized, self-reported questionnaire that asked the usual frequency of PA sessions with low (LPA), moderate (MPA), or vigorous intensity (VPA). Each participant's annual average cumulative PM10 was categorized as low to moderate and high PM10 on the basis of a cutoff value of 90th percentile.

RESULTS

A total of 81,326 participants (median follow-up, 45 months) were included. For participants engaged in MPA or VPA sessions, every 10% increase in the proportion of VPA to total PA sessions resulted in a 4.9% (95% CI, 1.0% to 9.0%; P=.014) increased and 2.8% (95% CI, -5.0% to -0.5%; P=.018) decreased risk of mortality for those exposed to high and low to moderate PM10, respectively (Pinteraction, <.001). For participants engaged only in LPA or MPA sessions, every 10% increase in the proportion of MPA to total PA sessions resulted in a 4.8% (95% CI, -8.9% to -0.4%; P=.031) and 2.3% (95% CI, -4.2% to -0.3%; P=.023) decreased risk of mortality for those exposed to high and low to moderate PM10, respectively (Pinteraction, .096).

CONCLUSION

We found that for the same level of total PA, MPA was associated with delayed mortality whereas VPA was associated with hastened mortality of older adults in high levels of PM10.

Personal strategies to mitigate the effects of air pollution exposure during sport and exercise: a narrative review and position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology

Air pollution is among the leading environmental threats to health around the world today, particularly in the context of sports and exercise. With the effects of air pollution, pollution episodes (eg, wildfire conflagrations) and climate change becoming increasingly apparent to the general population, so have their impacts on sport and exercise. As such, there has been growing interest in the sporting community (ie, athletes, coaches, and sports science and medicine team members) in practical personal-level actions to reduce the exposure to and risk of air pollution. Limited evidence suggests the following strategies may be employed: minimising all exposures by time and distance, monitoring air pollution conditions for locations of interest, limiting outdoor exercise, using acclimation protocols, wearing N95 face masks and using antioxidant supplementation. The overarching purpose of this position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology is to detail the current state of evidence and provide recommendations on implementing these personal strategies in preventing and mitigating the adverse health and performance effects of air pollution exposure during exercise while recognising the limited evidence base.

Cardiovascular Mortality, Habitual Exercise, and Particulate Matter 2.5 Exposure: A Longitudinal Cohort Study

INTRODUCTION

Habitual exercise may amplify the respiratory uptake of air pollutants in the lung, exacerbating the adverse effects of air pollution. However, it is unclear whether this can reduce the health benefits of habitual exercise (referred to as leisure-time exercise). Thus, the combined effects of habitual exercise and chronic exposure to ambient fine particulate matter 2.5 on cardiovascular mortality were examined among adults in Taiwan.

METHODS

A total of 384,128 adults were recruited between 2001 and 2016 and followed up to May 31, 2019. Participants' vital status was obtained by matching their unique identification numbers with records of cardiovascular death in the National Death Registry of Taiwan. A time-varying Cox regression model was used to analyze the data. Analyses were conducted in 2021.

RESULTS

Cardiovascular death risks were inversely associated with habitual exercise and positively associated with chronic exposure to particulate matter 2.5. The beneficial effects of habitual exercise on cardiovascular mortality were not modified by chronic exposure to particulate matter 2.5. Inactive participants with high particulate matter 2.5 exposure exhibited a 123% higher risk of cardiovascular death than high-exercise-group participants exposed to low levels of particulate matter 2.5 (95% CI=89, 163).

CONCLUSIONS

High level of habitual exercise combined with low exposure level of ambient particulate matter 2.5 is associated with the lowest risk of cardiovascular death. A higher level of habitual exercise is associated with a lower risk of cardiovascular death at all levels of particulate matter 2.5 exposure studied. The results indicate that habitual exercise is a safe health promotion strategy even for people residing in relatively polluted regions.

The preparation of ultrathin and porous electrospinning membranes of HKUST-1/PLA with good antibacterial and filtration performances

Developing degradable filter membranes that inhibit bacterial infection for preventing particle matter and infectious disease has been a research hotspot. Here, the fiber membranes of polylactic acid (PLA)/HKUST-1 with porous structure through the entire fiber matrix were prepared by electrospinning method. Due to the HKUST-1 incorporation and the presence of pore through fiber, the hydrophobicity of prepared membranes had been improved. The PLA/HKUST-1 membranes exhibited the good antibacterial activity against Escherichia coli and Staphylococcus aureus , and the antibacterial rate for S. aureus reached 99.99%. The filtration performance of PLA/HKUST-1 membranes was better than that of the melt-blown fabric although their thickness was only about one-third of the thickness of the currently commercial polypropylene melt-blown fabric.

The effects of ambient fine particulate matter exposure and physical activity on heart failure: A risk-benefit analysis of a prospective cohort study

BACKGROUND

Evidence supporting the adverse effects of air pollution and the benefits of physical activity (PA) on heart failure (HF) has continued to grow. However, their joint effects remain largely unknown.

METHODS

Our investigation included a total of 321,672 participants free of HF at baseline from the UK Biobank. Participants were followed up till March 2021. Information on participants' PA levels and additional covariates was collected by questionnaire. The annual fine particulate matter (PM_2.5) concentration was estimated using a Land Use Regression (LUR) model. Cox proportional hazards models were used to assess the associations of PA and PM_2.5 exposure with incident HF, as well as their interaction on both additive and multiplicative scales.

RESULTS

During a median follow-up of 12.0 years, 8212 cases of HF were uncovered. Compared with participants with low PA, the hazard ratios (HRs) were 0.69 (95 % CI: 0.65, 0.73) and 0.61 (95 % CI: 0.58, 0.65) for those with moderate and high PA, respectively. PM_2.5 was associated with an elevated risk of incident HF with an HR of 1.11 (95 % CI: 1.08, 1.14) per interquartile range (IQR) increment. The synergistic additive interaction between low PA and high PM_2.5 exposure on HF was observed. Compared with participants with high PA and low PM_2.5 exposure, those with low PA and high PM_2.5 exposure had the highest risk of HF [HR (95 % CI): 1.90 (1.76, 2.06)].

CONCLUSIONS

Our findings indicate that PA might still be an appropriate strategy to prevent HF for those living in areas with relatively high air pollution. Individuals with low PA may pay more attention to air pollution.

A Call for Action on Chronic Respiratory Diseases within Physical Activity Policies, Guidelines and Action Plans: Let's Move!

Global policy documents for the promotion of physical activity (PA) play an important role in the measurement, evaluation, and monitoring of population PA levels. The World Health Organisation (WHO) guidelines include, for the first time, recommendations for specific populations, including individuals living with a range of non-communicable diseases. Of note, is the absence of any chronic respiratory diseases (CRDs) within the recommendations. Globally, CRDs are highly prevalent, are attributable to significant individual and societal burdens, and are characterised by low PA. As a community, there is a need to come together to understand how to increase CRD representation within global PA policy documents, including where the evidence gaps are and how we can align with PA research in other contexts. In this commentary, the potential for synergy between evidence into the relationships between PA in CRDs globally and the relevance to current policies, guidelines and action plans on population levels of PA are discussed. Furthermore, actions and considerations for future research, including the need to harmonize and promote PA assessment (particularly in low- and middle-income countries) and encompass the synergistic influences of PA, sedentary behaviour and sleep on health outcomes in CRD populations are presented.

The influence of air pollution exposure on the short- and long-term health benefits associated with active mobility: A systematic review

Active mobility (AM), defined as walking and cycling for transportation, can improve health through increasing regular physical activity. However, these health improvements could be outweighed by harm from inhaling traffic-related air pollutants during AM participation. The interaction of AM and air pollutants on health is complex physiologically, manifesting as acute changes in health indicators that may lead to poor long-term health consequences. The aim of this study was to systematically review the current evidence of effect modification by air pollution (AP) on associations between AM and health indicators. Studies were included if they examined associations between AM and health indicators being modified by AP or, conversely, associations between AP and health indicators being modified by AM. Thirty-three studies met eligibility criteria. The main AP indicators studied were particulate matter, ultrafine particles, and nitrogen oxides. Most health indicators studied were grouped into cardiovascular and respiratory indicators. There is evidence of a reduction by AP, mainly ultrafine particles and PM_2.5, in the short-term health benefits of AM. Multiple studies suggest that long-term health benefits of AM are not negatively associated with levels of the single traffic-related pollutant NO₂. However, other studies reveal reduced long-term health benefits of AM in areas affected by high levels of pollutant mixtures. We recommend that future studies adopt consistent and rigorous study designs and include reporting of interaction testing, to advance understanding of the complex relationships between AM, AP, and health indicators.

Association of physical activity and air pollution exposure with the risk of type 2 diabetes: a large population-based prospective cohort study

BACKGROUND

The interplay between physical activity (PA) and air pollution in relation to type 2 diabetes (T2D) remains largely unknown. Based on a large population-based cohort study, this study aimed to examine whether the benefits of PA with respect to the risk of T2D are moderated by exposure to air pollution.

METHODS

UK Biobank participants (n = 359,153) without diabetes at baseline were included. Information on PA was obtained using the International Physical Activity Questionnaire short form. Exposure to air pollution, including PM_2.5, PM_coarse (PM_2.5-10), PM₁₀, and NO_2, was estimated from land use regression models. Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

During a median of 8.9 years of follow-up, 13,706 T2D events were recorded. Compared with a low PA level, the HRs for the risk of T2D among individuals with moderate and high PA were 0.82 (95% CI, 0.79-0.86) and 0.73 (95% CI, 0.70-0.77), respectively. Compared with low levels of air pollution, the HRs for risk of T2D for high levels of air pollution (PM_2.5, PM_coarse, PM₁₀, and NO₂) were 1.19 (1.14-1.24), 1.06 (1.02-1.11), 1.13 (1.08-1.18), and 1.19 (1.14-1.24), respectively. There was no effect modification of the associations between PA and T2D by air pollution (all P-interactions > 0.05). The inverse associations between PA and T2D in each air pollution stratum were generally consistent (all P for trend < 0.05).

CONCLUSION

A higher PA and lower air pollution level were independently associated with a lower risk of T2D. The beneficial effects of PA on T2D generally remained stable among participants exposed to different levels of air pollution. Further studies are needed to replicate our findings in moderately and severely polluted areas.

Long-term exposure to fine particulate matter modifies the association between physical activity and hypertension incidence

BACKGROUND

The trade-off between the benefits of regular physical activity (PA) and the potentially detrimental effects of augmented exposure to air pollution in highly polluted regions remains unclear. This study aimed to examine whether ambient fine particulate matter (PM_2.5) exposure modified the impacts of PA volume and intensity on hypertension risk.

METHODS

We included 54,797 participants without hypertension at baseline in a nationwide cohort of the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project. PA volume and intensity were assessed by questionnaire, and high-resolution (1 km ×1 km) PM_2.5 estimates were generated using a satellite-based model.

RESULTS

During 413,516 person-years of follow-up, 12,100 incident hypertension cases were identified. PM_2.5 significantly modified the relationship between PA and hypertension incidence (p_interaction < 0.001). Increased PA volume was negatively associated with incident hypertension in the low PM_2.5 stratum (<59.8 μg/m³, p_trend < 0.001), with a hazard ratio of 0.81 (95% confidence interval (95%CI): 0.74-0.88) when comparing the fourth with the first quartile of PA volume. However, the health benefits were not observed in the high PM_2.5 stratum (≥59.8 μg/m³, p_trend = 0.370). Moreover, compared with light PA intensity, vigorous intensity was related to a 20% (95%CI: 9%-29%) decreased risk of hypertension for participants exposed to low PM_2.5, but a 17% (95%CI: 4%-33%) increased risk for those with high PM_2.5 levels.

CONCLUSION

PA was associated with a reduced risk of hypertension only among participants with low PM_2.5 exposure. Our findings recommended regular PA to prevent hypertension in less polluted regions and reinforced the importance of air quality improvement.

Associations of private residential gardens versus other greenspace types with cardiovascular and respiratory disease mortality: Observational evidence from UK Biobank

BACKGROUND

Longitudinal evidence linking urban greenspace to reduced rates of all-cause and cause-specific mortality has mostly been established using greenness measures of limited specificity such as vegetation indices. Evidence on specific green space types, including private residential gardens is less well established.

METHODS

We examined associations of greenspace with all-cause, non-injury, cardiovascular disease (CVD) and respiratory disease deaths in UK Biobank - a national prospective cohort of adults with linked Office for National Statistics mortality records. We included private residential gardens and other greenspace types, e.g., public parks, sport facilities, using categories from Ordnance Survey MasterMap™ Greenspace. We used Cox proportional hazards models, adjusted for individual and area-level covariates, and stratified analyses by sex, household income, and area-level deprivation. In sensitivity analyses, we further adjusted for air pollution, road-traffic noise, indirect tobacco smoke exposure, and physical activity, and restricted analyses to non-movers.

RESULTS

In 232,926 participants, we observed 13,586 all-cause, 13,159 non-injury, 2,796 cardiovascular (CVD), and 968 respiratory disease deaths. Private residential garden cover showed inverse associations with all-cause, non-injury, CVD, and chronic respiratory disease mortality, after adjustment for covariates and other types of greenspace, with hazard ratios and 95 % confidence intervals of 0.94 (0.91, 0.97), 0.95 (0.92, 0.97), 0.92 (0.86, 0.98) and 0.87 (0.78, 0.98), respectively, per interquartile range (IQR) increase in private residential garden cover (IQR = 21.6 % increase within 100 m buffer). Other greenspace types showed weaker inverse associations with CVD and chronic respiratory disease mortality than private residential gardens. Sex, household income, and area level deprivation modified associations. Findings were robust to sensitivity analyses.

CONCLUSION

Our finding that private residential gardens substantially contributed to inverse associations of total greenspace with premature mortality has implications for public health and urban planning. Inequities in access, ownership, views and use of private residential gardens, and potential health inequities, should be addressed.

The influence of air pollution on residents’ outdoor exercise participation behaviour: Evidence from China Family Panel Studies

Using data from China Family Panel Studies (CFPS) and based on the Probit and Tobit models, this study investigates the impact of air pollution on residents’ outdoor exercise behaviour from the microscopic level. Specifically, this study examined the effects of PM2.5 index changes on residents’ decision to participate in outdoor exercise and the duration of outdoor exercise participation. The empirical results show that the increase of PM2.5 index has a significant inhibitory effect on residents’ participation in outdoor exercise, and has passed the robustness test and endogeneity test. Further testing found that the inhibitory effect was significantly different between urban and rural areas, and in the central, north-eastern and western regions where economic development was relatively backward, the conclusion that air pollution inhibited residents’ outdoor exercise behaviour still holds true. However, the level of air pollution had no significant effect on the outdoor exercise behaviour of residents in the eastern region. So, while air pollution discourages residents from participating in outdoor exercise, the results are more applicable to less economically developed areas.

Does kinesiophobia obstacle to physical activity and quality of life in asthmatic patients?

Kinesiophobia has been studied in musculoskeletal and neurological diseases. The aim of this descriptive study was to assess the level of kinesiophobia in stable asthmatic patients, and to determine whether it is an obstacle to physical activity and quality of life. A total of 62 asthmatic patients and 50 healthy control subjects were assessed using the tampa kinesiophobia scale (TSK) for kinesiophobia, International Physical Activity Questionnaire-Short Form (IPAQ-SF) for physical activity levels, and Asthma Quality of Life Questionnaire (AQLQ) for quality of life. A high degree of kinesiophobia was determined in 54.8% of the asthmatic patients. The TSK scores were significantly higher (P < 0.001), and the AQLQ scores were lower in the asthma group than in the control group (P < 0.001). The IPAQ-SF level and AQLQ score were lower (P < 0.001 for both) in the asthmatic group with a high kinesiophobia score. The TSK score was significantly associated with IPAQ-SF score (r = -0.889; P < 0.001) and AQLQ score (r = -0.820; P < 0.001) in asthmatic patients. According to linear regression analysis, kinesiophobia explained 84.40% of QoL and physical activity. Patients with a stable asthma were observed to have a high level of kinesiophobia compared with healthy subjects. High kinesiophobia levels may increase the disease burden by negatively affecting participation in physical activity and quality of life. While developing asthma education programs for asthma patients, it should be remembered that even in the stable period, kinesiophobia can develop. Preventive and therapeutic programs should include precautions to improve quality of life and physical activity against the effects of kinesiophobia.

The joint effects of physical activity and air pollution on type 2 diabetes in older adults

BACKGROUND

Older adults with type 2 diabetes are at higher risk of developing common geriatric syndromes and have a lower quality of life. To prevent type 2 diabetes in older adults, it's unclear whether the health benefits of physical activity (PA) will be influenced by the harms caused by increased exposure to air pollution during PA, especially in developing countries with severe air pollution problem. We aimed to investigate the joint effects of PA and long-term exposure to air pollution on the type 2 diabetes in older adults from China.

METHODS

This cross-sectional study was based on the China Multi-Ethnic cohort (CMEC) study. The metabolic equivalent of PA was calculated according to the PA scale during the CMEC baseline survey. High resolution air pollution datasets (PM₁₀, PM_2.5 and PM₁) were collected from open products. The joint effects were assessed by the marginal structural mean model with generalized propensity score.

RESULTS

A total of 36,562 participants aged 50 to 79 years were included in the study. The prevalence of type 2 diabetes was 10.88%. The mean (SD) level of PA was 24.93 (18.60) MET-h/d, and the mean (SD) level of PM₁₀, PM_2.5, and PM₁ were 70.00 (23.32) µg/m³, 40.45 (15.66) µg/m³ and 27.62 (6.51) µg/m³, respectively. With PM₁₀ < 92 µg/m³, PM_2.5 < 61 µg/m³, and PM₁ < 36 µg/m³, the benefit effects of PA on type 2 diabetes was significantly greater than the harms due to PMs when PA levels were roughly below 80 MET-h/d. With PM₁₀ ≥ 92 µg/m³, PM_2.5 ≥ 61 µg/m³, and PM₁ ≥ 36 µg/m³, the odds ratio (OR) first decreased and then rose rapidly with confidence intervals progressively greater than 1 and break-even points close to or even below 40 MET-h/d.

CONCLUSIONS

Our findings implied that for the prevention of type 2 diabetes in older adults, the PA health benefits outweighed the harms of air pollution except in extreme air pollution situations, and suggested that when the air quality of residence is severe, the PA levels should ideally not exceed 40 MET-h/d.

Air pollution and risk of chronic obstructed pulmonary disease: The modifying effect of genetic susceptibility and lifestyle

BACKGROUND

The effect of long-term exposure to air pollution on the development of chronic obstructive pulmonary disease (COPD) is still controversial, and the role of the interactions of air pollution with genetic risk and lifestyle in COPD risk is unclear.

METHODS

We included 452762 participants derived from the UK Biobank. Annual concentrations of air pollutions, including particle matter (PM_2.5, PM₁₀), nitrogen oxides (NO_x), and nitrogen dioxide (NO₂), were assessed using land-use regression model. We applied Cox proportional hazard model to evaluate the associations between air pollution and COPD risk. In addition, we constructed a polygenic risk score and a lifestyle score, and assessed whether genetic susceptibility and lifestyle modified the effect of air pollution on the COPD risk.

FINDINGS

Each interquartile range (IQR) increase in annual concentrations of PM_2.5, PM₁₀, NO_x, and NO₂ was associated with 1.17 (95% CI: 1.15,1.19), 1.05 (95% CI: 1.03,1.06), 1.13 (95% CI: 1.11,1.14), and 1.19 (95% CI: 1.16,1.21) times the risk of COPD, respectively. We observed an additive interaction between PM_2.5 and genetic risk (P-_interact=0.095), and a negative interaction between PM_2.5 and lifestyle (P-_interact=0.062). The HRs for each IQR increase in PM_2.5 were 1.21, (95% CI: 1.16-1.25) and 1.24, (95% CI: 1.21-1.26) in individuals with healthy and unfavourable lifestyle, respectively; and 1.16, (95% CI: 1.13-1.19) and 1.19, (95% CI: 1.16-1.22) in those with low genetic risk and high genetic risk, respectively. Participants with high air pollution exposure, high genetic risk and unfavourable lifestyle showed the highest risk of COPD.

INTERPRETATION

Long-term exposure to air pollution was associated with increased risk of COPD, especially in those with high genetic risk and unfavourable lifestyle.

FUNDING

None.

Association of air pollution exposure with exercise-induced oxygen desaturation in COPD

BACKGROUND

There is a link between exposure to air pollution and the increased prevalence of chronic obstructive pulmonary disease (COPD) and declining pulmonary function, but the association with O₂ desaturation during exercise in COPD patients with emphysema is unclear. Our aims were to estimate the prevalence of O₂ desaturation during exercise in patients with COPD, and determine the association of exposure to air pollution with exercise-induced desaturation (EID), the degree of emphysema, and dynamic hyperinflation (DH).

METHODS

We assessed the effects of 10-year prior to the HRCT assessment and 7 days prior to the six-minute walking test exposure to particulate matter with an aerodynamic diameter of < 10 µm (PM₁₀) or of < 2.5 µM (PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃) in patients with emphysema in this retrospective cohort study. EID was defined as a nadir standard pulse oximetry (SpO₂) level of < 90% or a delta (△)SpO₂ level of ≥ 4%. Ambient air pollutant (PM_2.5, PM₁₀, O₃, and NO₂) data were obtained from Taiwan Environmental Protection Administration (EPA) air-monitoring stations, usually within 10 km to each participant's home address.

RESULTS

We recruited 141 subjects with emphysema. 41.1% of patients with emphysema exhibited EID, and patients with EID had more dyspnea, worse lung function, more severe emphysema, more frequent acute exacerbations, managed a shorter walking distance, had DH, and greater long-term exposure to air pollution than those without EID. We observed that levels of 10-year concentrations of PM₁₀, PM_2.5, and NO₂ were significantly associated with EID, PM₁₀ and PM_2.5 were associated with the severity of emphysema, and associated with DH in patients with emphysema. In contrast, short-term exposure did not have any effect on patients.

CONCLUSION

Long-term exposure to ambient PM₁₀, PM_2.5 and NO₂, but not O₃, was associated with EID.

Risk/benefit tradeoff of habitual physical activity and air pollution on chronic pulmonary obstructive disease: findings from a large prospective cohort study

BACKGROUND

The combined health impact of physical activity (PA) and air pollution on chronic obstructive pulmonary disease (COPD) remains unclear. We investigated the joint effects of habitual PA and long-term fine particulate matter (PM2.5) exposure on COPD incidence in a prospective population-based cohort.

METHODS

A prospective cohort study was conducted using data from the UK Biobank. Incidence of COPD was ascertained through linkage to the UK National Health Services register. Annual mean PM2.5 concentration was obtained using land use regression model. PA was measured by questionnaire and wrist-worn accelerometer. Cox proportional hazard models were applied to examine the associations between PM2.5, PA, and COPD. Additive and multiplicative interactions were examined.

RESULTS

A total of 266,280 participants free of COPD at baseline were included in data analysis with an average follow-up of 10.64 years, contributing to around 2.8 million person-years. Compared with participants with low level of PA, those with higher PA levels had lower risks of COPD incidence [hazard ratio (HR): 0.769, 95% CI: 0.720, 0.820 for moderate level; HR: 0.726, 95% CI: 0.679, 0.776 for high level]. By contrast, PM2.5 was associated with increased risk of COPD (HR per interquartile range increment: 1.065, 95% CI: 1.032, 1.099). Limited evidence of interaction between habitual PA and PM2.5 exposure was found. Similar results were found for accelerometer-measured PA.

CONCLUSIONS

Our study suggests that habitual PA could reduce risk of COPD incidence, and such protective effects were not affected by ambient PM2.5 pollution exposure.

Cardiorespiratory fitness does not offset the increased risk of chronic obstructive pulmonary disease attributed to smoking: a cohort study

Though evidence suggests that higher cardiorespiratory fitness (CRF) levels can offset the adverse effects of other risk factors, it is unknown if CRF offsets the increased risk of chronic obstructive pulmonary disease (COPD) due to smoking. We aimed to evaluate the combined effects of smoking status and CRF on incident COPD risk using a prospective cohort of 2295 middle-aged and older Finnish men. Peak oxygen uptake, assessed with a respiratory gas exchange analyzer, was used as a measure of CRF. Smoking status was self-reported. CRF was categorised as low and high based on median cutoffs, whereas smoking status was classified into smokers and non-smokers. Multivariable-adjusted hazard ratios with confidence intervals (CIs) were calculated. During 26 years median follow-up, 119 COPD cases were recorded. Smoking increased COPD risk 10.59 (95% CI 6.64–16.88), and high CRF levels decreased COPD risk 0.43 (95% CI 0.25–0.73). Compared with non-smoker-low CRF, smoker-low CRF was associated with an increased COPD risk in multivariable analysis 9.79 (95% CI 5.61–17.08), with attenuated but persisting evidence of an association for smoker-high CRF and COPD risk 6.10 (95% CI 3.22–11.57). An additive interaction was found between smoking status and CRF (RERI = 6.99). Except for CRF and COPD risk, all associations persisted on accounting for mortality as a competing risk event. Despite a wealth of evidence on the ability of high CRF to offset the adverse effects of other risk factors, it appears high CRF levels have only modest attenuating effects on the very strong association between smoking and COPD risk.

Chronic fine particulate matter exposure, habitual exercise, and dyslipidemia: A longitudinal cohort study

Background:

Physical activity may increase the intake of air pollutants due to a higher ventilation rate, which may exacerbate the adverse health effects. This study investigated the combined effects of habitual exercise and long-term exposure to fine particulate matter (PM_2.5) on the incidence of dyslipidemia in a large longitudinal cohort in Taiwan.

Methods:

A total of 121,948 adults (≥18 years) who received at least two medical examinations from 2001 to 2016 were recruited, yielding 407,821 medical examination records. A satellite-based spatiotemporal model was used to estimate the 2-year average PM_2.5 concentration (i.e., the year of and the year before the medical examination) at each participant’s address. Information on habitual exercise within 1 month before the medical examination was collected using a standard self-administered questionnaire. A Cox regression model with time-dependent covariates was used to investigate the combined effects.

Results:

Compared with inactivity, moderate and high levels of exercise were associated with a lower incidence of dyslipidemia, with hazard ratios (HRs) (95% confidence intervals [CIs]) of 0.91 (0.88, 0.94) and 0.73 (0.71, 0.75), respectively. Participants with a moderate (22.37–25.96 μg/m³) or high (>25.96 μg/m³) level of PM_2.5 exposure had a higher incidence of dyslipidemia than those with a low level of PM_2.5 exposure (≤22.37 μg/m³), with HRs (95% CIs) of 1.36 (1.32, 1.40), and 1.90 (1.81, 1.99), respectively. We observed a statistically significant, but minor, interaction effect of PM_2.5 exposure and exercise on the development of dyslipidemia, with an overall hazard ratios (95% CI) of 1.08 (1.05, 1.10), indicating that an incremental increase in the level of exercise was associated with an 8% increase in the risk of dyslipidemia associated with every 10 μg/m³ increase in PM_2.5 exposure. However, the negative association between habitual exercise and dyslipidemia remained, regardless of the level of PM_2.5 exposure, suggesting that the benefits of increased habitual exercise outweighed the adverse effects of the increase in PM_2.5 intake during exercise.

Conclusions:

Increased levels of exercise and reduced levels of PM_2.5 exposures were associated with a lower incidence of dyslipidemia. Although an increase in habitual exercise slightly increased the risk of dyslipidemia associated with PM_2.5 exposure, the benefits of the increased habitual exercise outweighed the risks. Our findings suggest that habitual exercise is an effective approach for dyslipidemia prevention, even for people residing in relatively polluted areas.

Health impact assessment of auto rickshaw and cab drivers due to exposure to vehicular pollution in Delhi: an integrated approach

Vehicular emission is an important contributor to air pollution in the urban environment and impacts the health of commuters as well as drivers. The in-vehicle concentration of pollutants is known to be higher than the ambient environment and varies with the mode of transport. Thus, this study attempts to assess the health impacts of air pollution exposure on auto rickshaws and cab drivers. The study was conducted in Delhi using a triangular approach involving a health perception survey, lung function test and in-vehicle monitoring of particulate matter (PM₁, PM_2.5, PM₁₀) concentration to assess the health impacts of air pollution on auto rickshaw and cab drivers. A total of 150 respondents (75 from each occupation) were surveyed, and spirometry was performed for 40 respondents (20 from each occupation). Binary logistic regression showed auto rickshaw drivers were exposed to significantly higher in-vehicle PM concentrations in summers and winters and, thus, had a significantly higher risk of developing respiratory, ophthalmic and dermatological health symptoms (p< 0.05 and relative risk >1). Pulmonary function test showed obstructive lung impairment was reported only among auto rickshaw drivers (6%) and restrictive lung impairment was also more prevalent among auto rickshaw drivers (48%) than cab drivers (33%), suggesting a greater vulnerability of auto rickshaw drivers to respiratory health issues. Lung function impairment was associated with age (p= 0.002). The health and well-being of individuals is a matter of global concern, also highlighted in sustainable development goal no. 3. However, it was observed that neither auto rickshaw drivers nor cab drivers used formal/standard protective measures mainly due to unawareness or unaffordability. The study suggests increasing awareness and formulating guidelines to highlight the use of proper protective measures by these vulnerable groups and specific policy measures to protect outdoor workers like auto rickshaw drivers.

Combined effects of chronic PM2.5 exposure and habitual exercise on cancer mortality: a longitudinal cohort study

BACKGROUND

Exercise may increase the inhalation and deposition of air pollutants, which may counteract its beneficial effects. We thus examined the combined effects of chronic exposure to fine particulate matter (PM2.5) and habitual exercise on the risk of death from cancer in Taiwan.

PATIENTS AND METHODS

A total of 384 128 adults (≥18 years of age) were recruited for a medical screening programme between 2001 and 2016, yielding 842 384 medical-examination records. All participants were followed up until 31 May 2019. Vital data were obtained from the National Death Registry of Taiwan and the ambient PM2.5 exposure was estimated using a satellite-based spatiotemporal model. Information on habitual exercise was collected using a standard self-administered questionnaire. The time-dependent Cox-regression model was used to evaluate the combined effects.

RESULTS

A greater amount of habitual exercise was associated with lower risk of death from cancer, whilst a higher level of PM2.5 exposure was associated with a higher risk of death from cancer. The inverse associations of habitual exercise with death from cancer were not modified by chronic exposure to PM2.5. The participants in the group with a high level of exercise and a low level of PM2.5 exposure exhibited a 35% lower risk of death from cancer than those in the group with a low level of exercise and a high level of PM2.5 exposure (95% confidence interval: 28%, 42%).

CONCLUSIONS

Increased levels of exercise and reduced exposure levels of PM2.5 are associated with a lower risk of death from cancer. Habitual exercise reduces the risk of death from cancer regardless of the levels of chronic PM2.5 exposure. Our results indicate that habitual exercise is a suitable health-promotion strategy even for people who reside in moderately polluted regions.

High fitness levels offset the increased risk of chronic obstructive pulmonary disease due to low socioeconomic status: A cohort study

OBJECTIVE

Evidence suggests that higher cardiorespiratory fitness (CRF) levels can offset the increased risk of adverse outcomes due to other risk factors. The impact of high CRF levels on the increased risk of chronic obstructive pulmonary disease (COPD) due to low socioeconomic status (SES) is unknown. We aimed to assess the combined effects of SES and CRF on the future risk of COPD.

METHODS

We employed a prospective cohort of 2312 Finnish men aged 42-61 years at study entry. Socioeconomic status was self-reported and CRF was objectively assessed using respiratory gas exchange analyzers. Both exposures were categorized as low and high based on median cutoffs. Multivariable-adjusted hazard ratios (HRs) with confidence intervals (CIs) were estimated.

RESULTS

During 26.0 years median follow-up, 120 COPD cases occurred. Low SES was associated with increased COPD risk and high CRF was associated with reduced COPD risk. Compared with high SES-low CRF, low SES-low CRF was associated with an increased COPD risk 2.36 (95% CI: 1.44-3.87), with no evidence of an association for low SES-high CRF and COPD risk 1.46 (95% CI:0.82-2.60).

CONCLUSION

In middle-aged Finnish men, SES and CRF are each independently associated with COPD risk. However, high CRF levels offset the increased COPD risk related to low SES.

Demographic, lifestyle and comorbid risk factors for all-cause mortality in a Danish cohort of middle-aged adults with incident asthma

OBJECTIVE

We aimed to identify factors associated with all-cause mortality in adults with incident asthma.

DESIGN AND SETTING

Cross-sectional cohort study, in the metropolitan areas of Copenhagen and Aarhus, Denmark.

PARTICIPANTS

Adults aged 50-64 years enrolled in the Danish Diet, Cancer, and Health cohort were followed up from baseline (1993-1997) in the National Patients Registry for first-time admissions for asthma and vital status. We defined incident asthma as at least one first-time hospital admission with asthma as the primary registered diagnosis between baseline and end of follow-up (2013) in participants without previously known asthma. Among the cohort comprising 57 053 individuals, we identified 785 adults (aged 50-64) with incident asthma, of whom 76 died during follow-up.

PRIMARY AND SECONDARY OUTCOME MEASURES

Baseline reported socioeconomic and lifestyle traits, and comorbidities associated with all-cause mortality.

RESULTS

Self-reported leisure-time physical activity was associated with a substantial reduction in risk with an HR of 0.53 (95% CI 0.33 to 0.85). Being male, single and having a diagnosis of hypertension or diabetes were associated with an increased risk of all-cause mortality with an HR of 1.83 (95% CI 1.14 to 2.38), 2.16 (95% CI 2.06 to 4.40), 2.47 (95% CI 1.54 to 3.95) and of 2.42 (95% CI 0.96 to 6.11), respectively.

CONCLUSIONS

This long-term study of adults with hospital contacts for incident asthma revealed that self-reported leisure-time physical activity is associated with an approximately 50% reduction in all-cause mortality. In contrast, both hypertension and diabetes were associated with a higher risk of mortality.

Association of Cycling With All-Cause and Cardiovascular Disease Mortality Among Persons With Diabetes: The European Prospective Investigation Into Cancer and Nutrition (EPIC) Study

Importance

Premature death from all causes and cardiovascular disease (CVD) causes is higher among persons with diabetes.

Objective

To investigate the association between time spent cycling and all-cause and CVD mortality among persons with diabetes, as well as to evaluate the association between change in time spent cycling and risk of all-cause and CVD mortality.

Design, Setting, and Participants

This prospective cohort study included 7459 adults with diabetes from the European Prospective Investigation into Cancer and Nutrition study. Questionnaires regarding medical history, sociodemographic, and lifestyle information were administered in 10 Western European countries from 1992 through 2000 (baseline examination) and at a second examination 5 years after baseline. A total of 5423 participants with diabetes completed both examinations. The final updated primary analysis was conducted on November 13, 2020.

Exposures

The primary exposure was self-reported time spent cycling per week at the baseline examination. The secondary exposure was change in cycling status from baseline to the second examination.

Main Outcomes and Measures

The primary and secondary outcomes were all-cause and CVD mortality, respectively, adjusted for other physical activity modalities, diabetes duration, and sociodemographic and lifestyle factors.

Results

Of the 7459 adults with diabetes included in the analysis, the mean (SD) age was 55.9 (7.7) years, and 3924 (52.6%) were female. During 110 944 person-years of follow-up, 1673 deaths from all causes were registered. Compared with the reference group of people who reported no cycling at baseline (0 min/wk), the multivariable-adjusted hazard ratios for all-cause mortality were 0.78 (95% CI, 0.61-0.99), 0.76 (95% CI, 0.65-0.88), 0.68 (95% CI, 0.57-0.82), and 0.76 (95% CI, 0.63-0.91) for cycling 1 to 59, 60 to 149, 150 to 299, and 300 or more min/wk, respectively. In an analysis of change in time spent cycling with 57 802 person-years of follow-up, a total of 975 deaths from all causes were recorded. Compared with people who reported no cycling at both examinations, the multivariable-adjusted hazard ratios for all-cause mortality were 0.90 (95% CI, 0.71-1.14) in those who cycled and then stopped, 0.65 (95% CI, 0.46-0.92) in initial noncyclists who started cycling, and 0.65 (95% CI, 0.53-0.80) for people who reported cycling at both examinations. Similar results were observed for CVD mortality.

Conclusion and Relevance

In this cohort study, cycling was associated with lower all-cause and CVD mortality risk among people with diabetes independent of practicing other types of physical activity. Participants who took up cycling between the baseline and second examination had a considerably lower risk of both all-cause and CVD mortality compared with consistent noncyclists.

Association of the combined effects of air pollution and changes in physical activity with cardiovascular disease in young adults

AIMS

Little is known about the trade-off between the health benefits of physical activity (PA) and the potential harmful effects of increased exposure to air pollution during outdoor PA. We examined the association of the combined effects of air pollution and changes in PA with cardiovascular disease (CVD) in young adults.

METHODS AND RESULTS

This nationwide cohort study included 1 469 972 young adults aged 20-39 years. Air pollution exposure was estimated by the annual average cumulative level of particulate matter (PM). PA was calculated as minutes of metabolic equivalent tasks per week (MET-min/week) based on two consecutive health examinations from 2009 to 2012. Compared with the participants exposed to low-to-moderate levels of PM2.5 or PM10 who continuously engaged in ≥1000 MET-min/week of PA, those who decreased their PA from ≥1000 MET-min/week to 1-499 MET-min/week [PM10 adjusted hazard ratio (aHR) 1.22; 95% confidence interval (CI) 1.00-1.48] and to 0 MET-min/week (physically inactive; PM10 aHR 1.38; 95% CI 1.07-1.78) had an increased risk of CVD (P for trend <0.01). Among participants exposed to high levels of PM2.5 or PM10, the risk of CVD was elevated with an increase in PA above 1000 MET-min/week.

CONCLUSION

Reducing PA may lead to subsequent elevation of CVD risk in young adults exposed to low-to-moderate levels of PM2.5 or PM10, whereas a large increase in PA in a high-pollution environment may adversely affect cardiovascular health.

Combined effects of chronic PM2.5 exposure and habitual exercise on renal function and chronic kidney disease: A longitudinal cohort study

BACKGROUND

We investigated the combined effects of chronic PM_2.5 exposure and habitual exercise on the decline of renal function and the incidence of chronic kidney disease (CKD) in a large cohort in Taiwan.

METHODS

The present data analysis included a total of 108,615 participants aged 18 years or above who were recruited between 2001 and 2016. All participants underwent at least two medical examinations. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) equation. The incident of eGFR decline ≥30% was defined as a decline in eGFR of ≥30% during the study period, while the incident CKD was defined as an eGFR <60 mL/min/1.73 m² or a newly self-reported physician-diagnosed CKD in the subsequent visits. The satellite-based spatiotemporal model was used to estimate PM_2.5 exposure at each participant's address. Information on habitual exercise was collected using a standard self-administered questionnaire. The Cox regression model with time-dependent covariates was used for data analyses.

RESULTS

Higher habitual exercise was associated with lower risks of renal function decline and CKD development, whereas higher PM_2.5 exposure was associated with higher risks of renal function decline and CKD development. We found no significant interaction effect between PM_2.5 and habitual exercise, with an HR (95% CI) of 1.02 (0.97, 1.07) for incident eGFR decline ≥30% and 1.00 (0.95, 1.05) for CKD development. Compared to participants with inactive-exercise and high-PM_2.5, participants with high-exercise and low-PM_2.5 had 74% and 61% lower risks of renal function decline and CKD development, respectively.

CONCLUSION

Increased habitual exercise and reduced PM_2.5 exposures are associated with lower risks of renal function decline and CKD development. Habitual exercise reduces risks of renal function decline and CKD development regardless of the levels of chronic PM_2.5 exposure. Our study suggests that habitual exercise is a safe approach for kidney health improvement even for people residing in relatively polluted areas and should be promoted.

Habitual exercise is associated with reduced risk of diabetes regardless of air pollution: a longitudinal cohort study

AIMS/HYPOTHESIS

Physical activity may increase a person's inhalation of air pollutants and exacerbate the adverse health effects. This study aimed to investigate the combined associations of chronic exposure to particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) and habitual physical activity with the incidence of type 2 diabetes in Taiwan.

METHODS

We selected 156,314 non-diabetic adults (≥18 years old) who joined an ongoing longitudinal cohort between 2001 and 2016. Incident type 2 diabetes was identified at the follow-up medical examinations. Two-year mean PM2.5 exposure was estimated at each participant's address using a satellite-based spatiotemporal model. Information on physical activity and a wide range of covariates was collected using a standard self-administered questionnaire. We analysed the data using a Cox regression model with time-varying covariates. An interaction term between PM2.5 and physical activity was included to examine the overall interaction effects.

RESULTS

Compared with high physical activity, moderate and inactive/low physical activity were associated with a higher risk of diabetes (HR [95% CI] 1.31 [1.22, 1.41] and 1.56 [1.46, 1.68], respectively). Participants with moderate/high PM2.5 had a higher risk of type 2 diabetes than the participants exposed to low PM2.5 (HR 1.31 [1.22, 1.40] and 1.94 [1.76, 2.14], respectively). The participants with high physical activity and low PM2.5 had a 64% lower risk of type 2 diabetes than those with inactive/low physical activity and high PM2.5.

CONCLUSIONS/INTERPRETATION

Higher physical activity and lower PM2.5 exposure are associated with lower risk of type 2 diabetes. Habitual physical activity can reduce the risk of diabetes regardless of the levels of PM2.5 exposure. Our results indicate that habitual physical activity is a safe diabetes prevention strategy for people residing in relatively polluted regions.

The joint association of physical activity and fine particulate matter exposure with incident dementia in elderly Hong Kong residents

OBJECTIVE

The evidence for the beneficial effects of physical activity (PA) and potentially detrimental effects of long-term exposure to fine particulate matter (PM_2.5) on neurodegeneration diseases is accumulating. However, their joint effects remain unclear. We evaluated joint associations of habitual PA and PM_2.5 exposure with incident dementia in a longitudinal elderly cohort in Hong Kong.

METHODS

A total of 57,775 elderly participants (≥65 years) without dementia were enrolled during 1998-2001 and followed up till 2011. Their information on PA and other relevant covariates were collected at baseline (1998-2001) by a standard self-administered questionnaire, including PA volumes (high, moderate, low, and inactive) and types (aerobic exercise, traditional Chinese exercise, stretching exercise, walking slowly, and no exercise). Their annual mean PM_2.5 exposures at the residential address were estimated using a satellite-based spatiotemporal model. We then adopted the Cox proportional hazards model to examine the joint associations with the incidence of all-cause dementia, Alzheimer's diseases, and vascular dementia on additive and multiplicative scales.

RESULTS

During the follow-up period, we identified 1,157 incident cases of dementia, including 642 cases of Alzheimer's disease and 324 cases of vascular dementia. A higher PA level was associated with a lower risk of incident all-cause dementia (hazard ratio (HR) for the high-PA volume was 0.59 (95% CI, 0.47, 0.75), as compared with the inactive-PA), whereas a high level of PM_2.5 was related to the higher risk with an HR of 1.15 (95%CI: 1.00, 1.33) compared with the low-level of PM_2.5. No clear evidence was observed of interaction between habitual PA (volume and type) and PM_2.5 inhalation to incident dementia on either additive or multiplicative scale.

CONCLUSION

Habitual PA and long-term PM_2.5 exposure were oppositely related to incident dementia in the Hong Kong aged population. The benefits of PA remain in people irrespective of exposure to air pollution.

The Role of Nutritional Factors in Asthma: Challenges and Opportunities for Epidemiological Research

The prevalence of asthma has nearly doubled over the last decades. Twentieth century changes in environmental and lifestyle factors, including changes in dietary habits, physical activity and the obesity epidemic, have been suggested to play a role in the increase of asthma prevalence and uncontrolled asthma worldwide. A large body of evidence has suggested that obesity is a likely risk factor for asthma, but mechanisms are still unclear. Regarding diet and physical activity, the literature remains inconclusive. Although the investigation of nutritional factors as a whole (i.e., the “diet, physical activity and body composition” triad) is highly relevant in terms of understanding underlying mechanisms, as well as designing effective public health interventions, their combined effects across the life course has not received a lot of attention. In this review, we discuss the state of the art regarding the role of nutritional factors in asthma, for each window of exposure. We focus on the methodological and conceptual challenges encountered in the investigation of the complex time-dependent interrelations between nutritional factors and asthma and its control, and their interaction with other determinants of asthma. Lastly, we provide guidance on how to address these challenges, as well as suggestions for future research.

Outdoor Air Pollution and New-Onset Airway Disease. An Official American Thoracic Society Workshop Report

Although it is well accepted that air pollution exposure exacerbates preexisting airway disease, it has not been firmly established that long-term pollution exposure increases the risk of new-onset asthma or chronic obstruction pulmonary disease (COPD). This Workshop brought together experts on mechanistic, epidemiological, and clinical aspects of airway disease to review current knowledge regarding whether air pollution is a causal factor in the development of asthma and/or COPD. Speakers presented recent evidence in their respective areas of expertise related to air pollution and new airway disease incidence, followed by interactive discussions. A writing committee summarized their collective findings. The Epidemiology Group found that long-term exposure to air pollution, especially metrics of traffic-related air pollution such as nitrogen dioxide and black carbon, is associated with onset of childhood asthma. However, the evidence for a causal role in adult-onset asthma or COPD remains insufficient. The Mechanistic Group concluded that air pollution exposure can cause airway remodeling, which can lead to asthma or COPD, as well as asthma-like phenotypes that worsen with long-term exposure to air pollution, especially fine particulate matter and ozone. The Clinical Group concluded that air pollution is a plausible contributor to the onset of both asthma and COPD. Available evidence indicates that long-term exposure to air pollution is a cause of childhood asthma, but the evidence for a similar determination for adult asthma or COPD remains insufficient. Further research is needed to elucidate the exact biological mechanism underlying incident childhood asthma, and the specific air pollutant that causes it.

Objectively measured association between air pollution and physical activity, sedentary behavior in college students in Beijing

The purpose of this study is to examine the association between hourly air pollution on hourly physical activity (PA) and sedentary behavior (SB) among college students in Beijing, China. The secondary aim was to examine such associations varied at specific time. A total of 340 participants were recruited from the Tsinghua University, in Beijing, China. Accelerometers provided PA measures, including moderate-to-vigorous physical activity (MVPA), walking steps, energy expenditure and sedentary time for 7 consecutive days. Corresponding air pollution data by the Beijing Municipal Ecological Environment Bureau in the closed site (Wan Liu site) in Tsinghua University were collected including average hourly air quality index (AQI) and PM_2.5 (μg/m³). Associations were estimated using linear individual fixed-effect regressions. We also conducted an air pollution risk perception survey among 2307 freshmen (76.6% males) who were enrolled in Tsinghua in 2016, and the survey was done in May 22-26, 2017. A one level increase in hourly air quality index (AQI) was associated with a reduction in 1-h PA by 0.083 (95% confidence interval [CI] = -0.137, -0.029) minutes of MVPA, 8.8 (95% CI = -15.0, -2.6) walking steps, 0.65 (95% CI = -1.03, -0.27) kcals of energy expenditure. A 10 μg/m³ increase in air pollution concentration in hourly PM_2.5 was associated with a reduction in 1-h PA by 0.021 (95% confidence interval [CI] = -0.033, -0.010) minutes of MVPA, 2.2 (95% CI = -3.5, -0.9) walking steps, 0.170 (95% CI = -0.250, -0.089) kcals of energy expenditure an increase in 1-h sedentary behavior 0.045 (0.005, 0.0845). At specific time, stronger negative associations of AQI and PM_2.5 air pollution with PA at 8 a.m., 4 p.m., 5 p.m. and 7 p.m. Similarly, stronger positive associations of 1 h AQI and PM_2.5 air pollution with SB at 8 a.m., 9 a.m., 11 a.m., and 7 p.m. A total of 94.9% participants (n = 2235) responded "yes" to air pollution change activities in the survey, which may partially explain PA change. Air pollution may discourage physical activity and increases sedentary behavior among freshman students living in Beijing, China. This is preliminary study. The impact of air pollution on physical activity and sedentary behavior at a specific time may be different.

Air pollution, physical activity and health: A mapping review of the evidence

BACKGROUND

Exposure to air pollution and physical inactivity are both significant risk factors for non-communicable diseases (NCDs). These risk factors are also linked so that the change in exposure in one will impact risks and benefits of the other. These links are well captured in the active transport (walking, cycling) health impact models, in which the increases in active transport leading to increased inhaled dose of air pollution. However, these links are more complex and go beyond the active transport research field. Hence, in this study, we aimed to summarize the empirical evidence on the links between air pollution and physical activity, and their combined effect on individual and population health.

OBJECTIVES AND METHODS

We conducted a non-systematic mapping review of empirical and modelling evidence of the possible links between exposure to air pollution and physical activity published until Autumn 2019. We reviewed empirical evidence for the (i) impact of exposure to air pollution on physical activity behaviour, (ii) exposure to air pollution while engaged in physical activity and (iii) the short-term and (iv) long-term health effects of air pollution exposure on people engaged in physical activity. In addition, we reviewed (v) public health modelling studies that have quantified the combined effect of air pollution and physical activity. These broad research areas were identified through expert discussions, including two public events performed in health-related conferences.

RESULTS AND DISCUSSION

The current literature suggests that air pollution may decrease physical activity levels during high air pollution episodes or may prevent people from engaging in physical activity overall in highly polluted environments. Several studies have estimated fine particulate matter (PM2.5) exposure in active transport environment in Europe and North-America, but the concentration in other regions, places for physical activity and for other air pollutants are poorly understood. Observational epidemiological studies provide some evidence for a possible interaction between air pollution and physical activity for acute health outcomes, while results for long-term effects are mixed with several studies suggesting small diminishing health gains from physical activity due to exposure to air pollution for long-term outcomes. Public health modelling studies have estimated that in most situations benefits of physical activity outweigh the risks of air pollution, at least in the active transport environment. However, overall evidence on all examined links is weak for low- and middle-income countries, for sensitive subpopulations (children, elderly, pregnant women, people with pre-existing conditions), and for indoor air pollution.

CONCLUSIONS

Physical activity and air pollution are linked through multiple mechanisms, and these relations could have important implications for public health, especially in locations with high air pollution concentrations. Overall, this review calls for international collaboration between air pollution and physical activity research fields to strengthen the evidence base on the links between both and on how policy options could potentially reduce risks and maximise health benefits.

Ventilatory responses to constant load exercise following the inhalation of a short-acting ß2-agonist in a laboratory-controlled diesel exhaust exposure study in individuals with exercise-induced bronchoconstriction

OBJECTIVE

Individuals with exercise-induced bronchoconstriction (EIB) use ß₂-agonists to reduce respiratory symptoms during acute exercise. The resultingbronchodilation could increase the dose of inhaled pollutants and impair respiratory function when exercise is performedin air pollution. We aimed to assess respiratory responses in individuals with EIB when completing a cycling bout while being exposed to diesel exhaust (DE) or filtered air (FA) with and without the inhalation of salbutamol (SAL), a short-acting ß₂-agonist.

METHODS

In a double-blind, repeated-measures design, 19 participants with EIB (22-33 years of age) completed four visits: FA-placebo (FA-PLA), FA-SAL, DE-PLA, DE-SAL. After the inhalation of either 400 µg of SAL or PLA, participants sat in the exposure chamber for 60 min, breathing either FA or DE (PM_2.5 = 300 μg/m³). Participants then cycled for 30 min at 50 % of peak work rate while breathing FA or DE. Respiratory responses were assessed via spirometry, work of breathing (WOB), fractional use of ventilatory capacity (V̇_E/V̇_E,CAP), area under the maximal expiratory flow-volume curve (MEFV_AUC), and dyspnea during and following cycling.

RESULTS

Bronchodilation in response to SAL and acute cycling was observed, independent of FA/DE exposure. Specifically, FEV₁ was increased by 7.7 % (confidence interval (CI): 7.2-8.2 %; p < 0.01) in response to SAL, and MEFV_AUC was increased after cycling by 1.1 % (0.9-1.3 %; p = 0.03). Despite a significant decrease in total WOB by 6.2 J/min (4.7-7.5 J/min; p = 0.049) and a reduction in V̇_E/V̇_E,CAP by 5.8 % (5-6 %, p < 0.01) in the SAL exposures, no changes were observed in dyspnea. The DE exposure significantly increased V̇_E/V̇_E,CAP by 2.4 % (0.9-3.9 %; p < 0.01), but this did not affect dyspnea.

DISCUSSION

Our findings suggest that the use of SAL prior to moderate-intensity exercise when breathing high levels of DE, does not reduce respiratory function or exercise ventilatory responses for up to 60 min following exercise.

Respiratory Effects of Exposure to Traffic-Related Air Pollutants During Exercise

Traffic-related air pollution (TRAP) is increasing worldwide. Habitual physical activity is known to prevent cardiorespiratory diseases and mortality, but whether exposure to TRAP during exercise affects respiratory health is still uncertain. Exercise causes inflammatory changes in the airways, and its interaction with the effects of TRAP or ozone might be detrimental, for both athletes exercising outdoor and urban active commuters. In this Mini-Review, we summarize the literature on the effects of exposure to TRAP and/or ozone during exercise on lung function, respiratory symptoms, performance, and biomarkers. Ozone negatively affected pulmonary function after exercise, especially after combined exposure to ozone and diesel exhaust (DE). Spirometric changes after exercise during exposure to particulate matter and ultrafine particles suggest a decrease in lung function, especially in patients with chronic obstructive pulmonary disease. Ozone frequently caused respiratory symptoms during exercise. Women showed decreased exercise performance and higher symptom prevalence than men during TRAP exposure. However, performance was analyzed in few studies. To date, research has not identified reliable biomarkers of TRAP-related lung damage useful for monitoring athletes' health, except in scarce studies on airway cells obtained by induced sputum or bronchoalveolar lavage. In conclusion, despite partly counteracted by the positive effects of habitual exercise, the negative effects of TRAP exposure to pollutants during exercise are hard to assess: outdoor exercise is a complex model, for multiple and variable exposures to air pollutants and pollutant concentrations. Further studies are needed to identify pollutant and/or time thresholds for performing safe outdoor exercise in cities.

Association of combined effects of physical activity and air pollution with diabetes in older adults

BACKGROUND

Physical activity (PA), especially outdoor PA, may have twofold effects on diabetes risk: the health benefits of PA and the potential detrimental effects caused by augmented exposure to air pollution. We examined the association of combined effects of PA and air pollution with diabetes in older adults.

METHODS

The study participants consisted of 1,259,871 older adults aged 58 years or more from the Korean National Health Insurance Service database. The exposure to air pollution was estimated by the average ambient levels of particulate matter (PM) of the participants' residence area. Cox proportional hazards models were used to evaluate the adjusted hazard ratios and 95% confidence intervals of developing diabetes according to the combined effect of moderate to vigorous physical activity (MVPA) and air pollution exposure.

RESULTS

Engaging in 5 or more times of MVPA/week was associated with decreased risk of diabetes within groups with both high and low/moderate levels of exposure to PM10 (low/moderate PM10 aHR 0.91, 95% CI 0.89-0.93; high PM10 aHR 0.97, 95% CI 0.94-0.99) or PM2.5 (low/moderate PM2.5 aHR 0.88, 95% CI 0.85-0.90; high PM10 aHR 0.95, 95% CI 0.91-0.99) exposure. The risk-reducing effects upon MVPA tended to be slightly attenuated, which showed the reverse J-shaped association, but still significant, among those who were exposed to a high level of air pollution. The association was consistent among stratified analyses according to the possible confounders.

CONCLUSION

MVPA may be inversely associated with the risk of diabetes development within groups with both high and low/moderate levels of exposure to PM10 or PM2.5 in older adults. Future studies are necessary to validate whether the positive health effects of MVPA outweigh the potential detrimental effects due to augmented exposure to air pollution during MVPA.

Dust exposure and the impact on hospital readmission of farming and wood industry workers for asthma and chronic obstructive pulmonary disease (COPD)

Objectives:

It is still not well established how occupational air pollutants affect the prognosis of asthma or chronic obstructive pulmonary disease (COPD). This study uses nationwide Danish registers and quantitative dust industry exposure matrices (IEM) for the farming and wood industries to estimate whether previous year dust exposure level impacts hospital readmissions for workers diagnosed with asthma or COPD.

Methods:

We identified all individuals with a first diagnosis of either asthma (769 individuals) or COPD (342 individuals) between 1997 and 2007 and followed them until the next hospital admission for asthma or COPD, emigration, death or 31 December 2007. We included only individuals who worked in either the wood or farming industries at least one year during follow-up. We used logistic regression analysis to investigate associations between dust exposure level in the previous year and hospital readmission, adjusting for sex, age, time since first diagnosis, socioeconomic status, and labor force participation.

Results:

Asthma readmissions for individuals with low and high dust exposure were increased [adjusted rate ratio (RR_adj) 2.52, 95% confidence interval (CI) 1.45–4.40] and RR_adj 2.64 (95% CI 1.52–4.60), respectively. For COPD readmission, the risk estimates were RR_adj 1.36 (95% CI 0.57–3.23) for low and RR_adj 1.20 (95% CI 0.49–2.95) for high exposure level in the previous year. For asthma readmission, stratified analyses by type of dust exposure during follow-up showed increased risks for both wood dust [RR_adj 2.67 (95% CI 1.35–5.26) high exposure level] and farming dust [RR_adj 3.59 (95% CI 1.11–11.59) high exposure level]. No clear associations were seen for COPD readmissions.

Conclusions:

This study indicates that exposure to wood or farm dust in the previous year increases the risk of hospital readmission for individuals with asthma but not for those with COPD.

Independent and Opposing Associations of Habitual Exercise and Chronic PM2.5 Exposures on Hypertension Incidence

BACKGROUND

We investigated the joint associations of habitual physical activity (PA) and long-term exposure to fine particulate matter (PM_2.5) with the development of hypertension in a longitudinal cohort in Taiwan.

METHODS

We selected 140 072 adults (≥18 years of age) without hypertension who joined a standard medical screening program with 360 905 medical examinations between 2001 and 2016. PM_2.5 exposure was estimated at each participant's address using a satellite data-based spatiotemporal model with 1 km² resolution. Information on habitual PA and a wide range of covariates was collected using a standard self-administered questionnaire. We used the Cox regression model with time-dependent covariates to examine the joint associations.

RESULTS

The mean age of all observations was 41.7 years, and 48.8% were male. The mean value for systolic and diastolic blood pressure was 112.5 and 68.7mm Hg, respectively. Approximately 34.2% of all observations were inactive (0 metabolic equivalence values-hours), 29.8% had moderate-PA (median [interquartile range]; 3.75 [3.38 to 4.38] metabolic equivalence values-hours), and 36.0% had high-PA (15.7 [10.3 to 24.8] metabolic equivalence values-hours). The mean±SD of PM_2.5 was 26.1±7.3 μg/m³. The prevalence of cardiovascular disease, diabetes mellitus, and cancer was 2.1%, 2.9%, and 1.5%, respectively. After adjusting for a wide range of covariates (including a mutual adjustment for PA or PM_2.5), a higher PA level was associated with a lower risk of hypertension (hazard ratio [HR] for the moderate- and high-PA was 0.93 [95% CI, 0.89-0.97] and 0.92 [95% CI, 0.88-0.96], respectively, as compared with the inactive-PA), whereas a higher level of PM_2.5 was associated with a higher risk of hypertension (HR for the moderate- and high-PM_2.5 was 1.37 [95% CI, 1.32-1.43] and 1.92 [95% CI, 1.81-2.04], respectively, as compared with the low-PM_2.5 group]. No significant interaction was observed between PA and PM_2.5 (HR 1.01 [95% CI, 1.00-1.02]).

CONCLUSIONS

A high-PA and low PM_2.5 exposure were associated with a lower risk of hypertension. The negative association between PA and hypertension remained stable in people exposed to various levels of PM_2.5, and the positive association between PM_2.5 and hypertension was not modified by PA. Our results indicated that PA is a suitable hypertension prevention strategy for people residing in relatively polluted regions.

[Combined effects of different environmental factors on health: air pollution, temperature, green spaces, pollen, and noise]

Environmental factors affect the health and wellbeing of urban residents. However, they do not act individually on humans, but instead show potential synergistic or antagonistic effects. Questions that arise from this are: How does a combination of air pollutants with other environmental factors impact health? How well are these associations evidenced? What methods can we use to look at them? In this article, methodical approaches regarding the effects of a combination of various environmental factors are first described. Environmental factors are then examined, which together with different air pollutants, have an impact on human health such as ambient temperature, noise, and pollen as well as the effect of green spaces. Physical activity and nutrition are addressed regarding the attenuation of health effects from air pollution.While there is often clear evidence of health effects of single environmental stressors, there are still open questions in terms of their interaction. The research methods required for this still need to be further developed. The interrelationship between the different environmental factors make it clear that (intervention) measures for reducing single indicators are also interlinked. Regarding traffic, switching from passive to active transport (e.g., due to safe cycle paths and other measures) leads to less air pollutants, smaller increases in temperature in the long term, and at the same time improved health of the individual. As a result, sensible planning of the built environment has great potential to reduce environmental stressors and improve people's health and wellbeing.

Benefits of physical activity not affected by air pollution: a prospective cohort study

BACKGROUND

Physical activity (PA) is beneficial to human health, whereas long-term exposure to air pollution is harmful. However, their combined effects remain unclear. We aimed to estimate the combined (interactive) mortality effects of PA and long-term exposure to fine particulate matter (PM2.5) among older adults in Hong Kong.

METHODS

Participants aged ≥65 years from the Elderly Health Service Cohort (n = 66 820) reported their habitual PA at baseline (1998-2001) and were followed up till 31 December 2011. We used a satellite-based spatiotemporal model to estimate PM2.5 concentration at the residential address for each participant. We used Cox proportional hazards regression to assess the interaction between habitual PA and long-term exposure to PM2.5 on cardiovascular and respiratory mortality. We tested for additive interaction by estimating relative excess risk due to interaction and multiplicative interaction employing P-value for the interaction term.

RESULTS

The death risks were inversely associated with a higher volume of PA and were positively associated with long-term exposure to PM2.5. The benefits of PA were more pronounced for participation in traditional Chinese exercise (e.g. Tai Chi) and aerobic exercise (e.g. cycling). We found little evidence of interaction between PA (volume and type) and long-term exposure to PM2.5 on either additive or multiplicative scales.

CONCLUSIONS

In this cohort of older Chinese adults, PA may decrease the risk of mortality, be it in areas of relatively good or bad air quality. The beneficial mortality effects of habitual PA outweighed the detrimental effects of long-term exposure to air pollution in Hong Kong.

Personal strategies to minimise effects of air pollution on respiratory health: advice for providers, patients and the public

As global awareness of air pollution rises, so does the imperative to provide evidence-based recommendations for strategies to mitigate its impact. While public policy has a central role in reducing air pollution, exposure can also be reduced by personal choices. Qualified evidence supports limiting physical exertion outdoors on high air pollution days and near air pollution sources, reducing near-roadway exposure while commuting, utilising air quality alert systems to plan activities, and wearing facemasks in prescribed circumstances. Other strategies include avoiding cooking with solid fuels, ventilating and isolating cooking areas, and using portable air cleaners fitted with high-efficiency particulate air filters. We detail recommendations to assist providers and public health officials when advising patients and the public regarding personal-level strategies to mitigate risk imposed by air pollution, while recognising that well-designed prospective studies are urgently needed to better establish and validate interventions that benefit respiratory health in this context.

Quiet, clean, green, and active: A Navigation Guide systematic review of the impacts of spatially correlated urban exposures on a range of physical health outcomes

BACKGROUND

Recent epidemiologic analyses have considered impacts of multiple spatially correlated urban exposures, but this literature has not been systematically evaluated.

OBJECTIVES

To characterize the long-term impacts of four distinct spatially correlated urban environmental exposures - traffic-related air pollution (TRAP), noise, natural spaces, and neighborhood walkability - by evaluating studies including measures of at least two such exposures in relationship to mortality, cardiovascular disease, chronic respiratory disease, allergy, type 2 diabetes, or reproductive outcomes.

METHODS

Following the Navigation Guide framework, the literature was searched for studies published since 2003 and meeting predefined inclusion criteria. Identified studies were scored individually for risk of bias and all studies related to an exposure-group set were appraised for overall quality and strength of evidence.

RESULTS

A total of 51 individual studies (TRAP and noise: n = 29; TRAP and natural spaces: n = 10; noise and natural spaces: n = 2; TRAP, noise, and natural spaces: n = 7; TRAP, noise, natural spaces, and walkability: n = 3) were included. When TRAP and noise were considered jointly, evidence was sufficient for increased cardiovascular morbidity with higher noise exposures; sufficient for no effect of TRAP on CVD morbidity; sufficient for increased mortality with higher TRAP exposures, but limited for noise; and limited for increased adverse reproductive outcomes with higher TRAP exposures and no effect of noise. Looking at natural spaces and TRAP, there was limited evidence for lower risk of chronic respiratory disease and small increases in birthweight with greater natural space; this relationship with birthweight persisted after adjustment for noise as well. Evidence was inadequate for all other exposure groups and outcomes.

DISCUSSION

Studies that properly account for the complexity of relationships between urban form and physical health are limited but suggest that even highly correlated exposures may have distinct effects.

REVIEW REGISTRATION

PROSPERO 2018 CRD42018106050.

Combined Effects of Physical Activity and Air Pollution on Cardiovascular Disease: A Population-Based Study

Background Physical activity (PA), particularly outdoor PA, may have dual effects on cardiovascular disease (CVD) risk: health benefits of exercise and potential harmful effects attributable to increased exposure to air pollution. We examined the combined effects of PA and air pollution on CVD. Methods and Results Sampling from a nationwide cohort study of the Korean National Health Insurance Service, we examined 189 771 adults aged ≥40 years who underwent health examination between 2009 and 2010. PA was measured with a questionnaire on the weekly frequency and intensity. Ambient levels of particulate matter 10, 2.5 (PM10, PM2.5) were estimated by the residency of participants. We conducted Cox proportional hazard regression analysis to estimate the relationship between CVD risk and combined effects of PA and air pollution. Subjects with moderate to vigorous PA ≥5 times/week and high PM10 exposure had lower risk of CVD (adjusted hazard ratio [aHR], 0.73; 95% CI, 0.62-0.87), coronary heart disease (aHR, 0.76; 95% CI, 0.59-0.98), and stroke (aHR, 0.70; 95% CI, 0.56-0.88). The inverse association between PA and CVD risk was consistent when the analysis was performed for subjects with low/moderate PM10 exposure. When using PM2.5 data, the results were also consistent. Conclusions Moderate to vigorous PA appeared to reduce the risk of CVD within groups of both high and low PM10 or PM2.5 levels. Further studies are needed to validate whether the health benefits of PA outweigh the potential harmful effects resulting from increased exposure to air pollution during PA.