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

Sufficient sleep and physical activity can relieve the effects of long-term exposure to particulate matter on depressive symptoms among 0.31 million children and adolescents from 103 counties in China

BACKGROUND

Although long-term exposures to air pollutants have been linked to mental disorders, existing studies remain limited and inconsistent. We investigated the relationship between exposure to particulate matter (PM) and depressive symptoms, as well as the potential role of sleep duration and physical activity.

METHOD

Using the surveillance data (2019 to 2022) of common diseases and risk factors among 312,390 students aged 10-25 years, logistic regression, generalized liner model (GLM) and restricted cubic spline (RCS) were employed to investigate the relationship between long-term exposure to PM and depressive symptoms.

RESULT

Significant associations were found between PM1 (OR = 1.21, 95 % CI: 1.12-1.32), PM2.5 (OR = 1.24, 95 % CI: 1.19-1.38), and PM10 (OR = 1.87, 95 % CI: 1.69-2.07) and increased risks of depressive symptoms. Sleep duration and physical activity relieved these associations. The odds ratios (ORs) of PM1, PM2.5, and PM10 on depressive symptoms were lower in group with sufficient sleep (1.02 vs. 1.49, 1.20 vs. 1.80, 2.15 vs. 2.23), lower in group with high level MVPA (1.13 vs. 1.48, 1.14 vs. 1.58, 1.85 vs. 2.38), and lower in group with high level outdoor activity (1.19 vs. 1.55, 1.23 vs. 1.63, 1.83 vs. 2.72).

LIMITATIONS

Conclusions about causality remain speculative because of the cross-sectional design.

CONCLUSION

Sufficient sleep duration and outdoor activity may mitigate the decline in mental health among adults in developing countries caused by long-term exposure to PM. This contribution enhanced our understanding of the mechanisms linking air pollution to mental health.

Exploring the Interplay Between Climate Change, 24-Hour Movement Behavior, and Health: A Systematic Review

BACKGROUND

Given the emergence of climate change and health risks, this review examined potential relationships between varying indicators of climate change, movement behaviors (ie, physical activity [PA], sedentary behavior, and sleep), and health.

METHODS

Seven databases were searched in March 2020, April 2023, and April 2024. To be included, studies must have examined indicators of climate change and at least one of the movement behaviors as either an exposure or a third variable (ie, mediator/moderator), and a measure of health as outcome. Evidence was summarized by the role (mediator/moderator) that either climate change or movement behavior(s) has with health measures. Relationships and directionality of each association, as well as the strength and certainty of evidence were synthesized.

RESULTS

A total of 79 studies were eligible, representing 6,671,791 participants and 3137 counties from 25 countries (40% low- and middle-income countries). Of 98 observations from 17 studies that examined PA as a mediator, 34.7% indicated that PA mediated the relationship between climate change and health measure such that indicators of adverse climate change were associated with lower PA, and worse health outcome. Of 274 observations made from 46 studies, 28% showed that PA favorably modified the negative association between climate change and health outcome. Evidence was largely lacking and inconclusive for sedentary behavior and sleep, as well as climate change indicators as an intermediatory variable.

CONCLUSIONS

PA may mitigate the adverse impact of climate change on health. Further evidence is needed to integrate PA into climate change mitigation, adaptation, and resilience strategies.

Exposure to PM2.5 and its constituents is associated with metabolic dysfunction-associated fatty liver disease: a cohort study in Northwest of China

Accumulating animal studies have demonstrated associations between ambient air pollution (AP) and metabolic dysfunction-associated fatty liver disease (MAFLD), but relevant epidemiological evidence is limited. We evaluated the association of long-term exposure to AP with the risk of incident MAFLD in Northwest China. The average AP concentration between baseline and follow-up was used to assess individual exposure levels. Cox proportional hazard models and restricted cubic spline functions (RCS) were used to estimate the association of PM2.5 and its constituents with the risk of MAFLD and the dose-response relationship. Quantile g-computation was used to assess the joint effects of mixed exposure to air pollutants on MAFLD and the weights of the various pollutants. We observed 1516 cases of new-onset MAFLD, with an incidence of 10.89%. Increased exposure to pollutants was significantly associated with increased odds of MAFLD, with hazard ratios (HRs) of 2.93 (95% CI: 1.22, 7.00), 2.86 (1.44, 5.66), 7.55 (3.39, 16.84), 4.83 (1.89, 12.38), 3.35 (1.35, 8.34), 1.89 (1.02, 1.62) for each interquartile range increase in PM2.5, SO42-, NO3-, NH4+, OM, and BC, respectively. Stratified analyses suggested that females, frequent exercisers and never-drinkers were more susceptible to MAFLD associated with ambient PM2.5 and its constituents. Mixed exposure to SO42-, NO3-, NH4+, OM and BC was associated with an increased risk of MAFLD, and the weight of BC had the strongest effect on MAFLD. Exposure to ambient PM2.5 and its constituents increased the risk of MAFLD.

Emerging concern on air pollution and health: Trade-off between air pollution exposure and physical activity

Air pollution is a major contributor to the global disease burden, especially affecting respiratory and cardiovascular health. However, physical activity is associated with improved lung function, a slower decline in lung function, and lower mortality. The public is more likely to be exposed to air pollution during outdoor physical activity. However, studies on how long-term and short-term exposure to air pollution interacts with physical activity yield inconsistent results, and the thresholds for air pollution and physical activity remain unclear. Thus, more studies are needed to provide sufficient evidence to guide the public to safely engage in outdoor physical activity when exposed to air pollution.

Risk/benefit trade-off of habitual physical activity and air pollution on mortality: A large-scale prospective analysis in the UK Biobank

BACKGROUND

Previous observational studies have indicated associations of physical activity (PA) and air pollution with mortality. A few studies have evaluated air pollution and PA interactions for health. Still, the trade-off between the harmful effects of air pollution exposure and the protective effects of PA remains controversial and unclear.

OBJECTIVE

This study aimed to investigate the joint association of air pollution and PA with mortality risks.

METHODS

This prospective cohort study included 322,092 participants from 2006 to 2010 and followed up to 2021 in the UK Biobank study. The concentrations of air pollutants (2006-2010), including particulate matter (PM) with diameters <=2.5 mm (PM2.5), <=10 mm (PM10), and between 2.5 and 10 mm (PM2.5-10), and nitrogen oxides (NO2 and NOx) were obtained. Information on PA measured by the International Physical Activity Questionnaire short form (2006-2010) and wrist-worn accelerometer (2013-2015) were collected. All-cause and cause-specific mortalities were recorded. Cox proportional hazard models were used to investigate the associations of air pollution exposure and PA with mortality risks. The additive and multiplicative interactions were also examined.

RESULTS

During a mean follow-up of 11.83 years, 16629 deaths were recorded. Compared with participants reporting low PA, higher PA was negatively associated with all-cause [hazard ratio (HR), 0.74; 95% CI, 0.71-0.78], cancer (HR, 0.85; 95% CI, 0.80-0.90), CVD (HR, 0.79; 95% CI, 0.71-0.87), and respiratory disease-specific mortality (HR, 0.51; 95% CI, 0.44-0.60). Exposure to PM2.5 (HR, 1.05; 95% CI, 1.00-1.09) and NOx (HR, 1.06; 95% CI, 1.02-1.10) was connected with increased all-cause mortality risk, and significant PM2.5-associated elevated risks for CVD mortality and NOx-associated elevated risks for respiratory disease mortality were observed. No obvious interaction between PA and PM2.5 or NOx exposure was detected.

CONCLUSIONS

Our study provides additional evidence that higher PA and lower air pollutant levels are independently connected with reduced mortality risk. The benefits of PA are not significantly affected by long-term air pollution exposure, indicating PA can be recommended to prevent mortality regardless of air pollution levels. Our findings highlight the importance of public health policies and interventions facilitating PA and reducing air pollution in reducing mortality risks and maximizing health benefits. Future investigation is urgently needed to identify these findings in areas with severe air pollution conditions.

Interaction of physical activity and low-level air pollution on cardiovascular disease: a prospective cohort study in UK Biobank

To investigate the associations of physical activity (PA), low-level air pollution, and interaction on cardiovascular diseases (CVD) incidence based on the UK Biobank. PA was measured by the International Physical Activity Questionnaire and five air pollutants were estimated using Land Use Regression. All association estimates were based on Cox regression. Dose-response relationship was explored by restricted cubic spline, while multiplicative and additive interaction were examined by Pinteraction and relative excess risk due to interaction (RERI). As deviating proportional hazards assumption, we analyzed data as follow-up < 4 years and ≥ 4 years, separately. PA with 1000-4000 Metabolic Equivalent Task (MET) min/week showed the strongest protective impact on CVD incidence, while only low-level nitrogen dioxides (NO2) showed negative impact among five air pollutants and was considered for further analysis. Multiplicative interaction between PA and NO2 was observed during ≥ 4 years follow-up (Pinteraction = 0.049) while not during < 4 years (Pinteraction = 0.290). Positive additive interactions were found for high PA and low NO2 (< 20 μg/m3) group (RERI: 0.07, 95% confidence intervals: 0.02-0.11) during < 4 years, and for moderate PA with NO2 at 40- μg/m3 (0.07, 0.02-0.13) and < 20 μg/m3 (0.07, 0.02-0.12), while high PA showed similar results with NO2 at 40-, 20- and < 20 μg/m3 during ≥ 4 years. PA about 1000-4000 METs min/week showed the lowest CVD risk. Possibility of interaction with PA and NO2 is more likely to present with the increase in follow-up duration. We call for the optimal thresholds of PA, and exploring interaction thoroughly by considering types of PA.

Physiological impacts of atmospheric pollution: Effects of environmental air pollution on exercise

In this review, we discuss some of the recent advances in our understanding of the physiology of the air pollution and exercise. The key areas covered include the effect of exercise intensity, the effects of pre-exposure to air pollution, acclimation to air pollution, and the utility of masks during exercise. Although higher intensity exercise leads to an increase in the inhaled dose of pollutants for a given distance traveled, the acute effects of (diesel exhaust) air pollution do not appear to be more pronounced. Second, exposure to air pollution outside of exercise bouts seems to have an effect on exercise response, although little research has examined this relationship. Third, humans appear to have an ability to acclimate to ground level ozone, but not other pollutants. And finally, masks may have beneficial effects on certain outcomes at low intensity exercise in pollution with significant levels of particles, but more study is required in realistic conditions.

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.

The impact of long-term PM1 exposure on all-cause mortality and its interaction with BMI: A nationwide prospective cohort study in China

BACKGROUND

China has a serious air pollution problem and a high prevalence of obesity. The interaction between the two and its impact on all-cause mortality is a public health issue of great concern.

OBJECTIVES

This study aimed to investigate the association between long-term exposure to particulate matter with aerodynamic diameter ≤ 1 μm (PM1) and all-cause mortality, as well as the interaction effect of body mass index (BMI) in the association.

METHODS

A total of 33,087 participants from 162 counties in 25 provinces in China were included, with annual average PM1 exposure being estimated based on the county address. The PM1-mortality relation was evaluated using the time-varying Cox proportional hazards models, with the dose-response relationship being fitted using the penalized splines. Besides, the potential interaction effect of BMI in the PM1-mortality relation was evaluated.

RESULTS

The incidence of all-cause deaths was 76.99 per 10,000 person-years over a median of 8.2 years of follow-up. After controlling for potential confounders, the PM1-mortality relation was approximately J-shaped. The full-adjustment analysis observed the hazard ratio (HR) of all-cause mortality was 1.114 [95 % confidence interval (CI): 1.017-1.220] corresponding to a 10 μg/m3 rise in PM1 concentration. Further stratified analyses suggested the adverse effects of PM1 might be more pronounced among the underweight.

DISCUSSION

Higher PM1 concentrations were associated with an increase in all-cause mortality. The BMI might further alter the relation, and the underweight population was the sensitive subgroup of the population that needed to be protected.

The effect of various air pollution and participants' age on semen quality in southern Taiwan

OBJECTIVE

This study aimed to investigate the association between semen quality and air pollution in southern Taiwan.

MATERIALS AND METHODS

In this retrospective study, 4338 males aged 21-70 years were recruited between 2001 and 2018 from a reproductive medical center. Semen quality was assessed according to standardized methods outlined in the World Health Organization (WHO) Laboratory Manual 1999 and 2010, including total sperm count, progressive sperm motility (%), rapid progressive sperm motility (%), and sperm with normal morphology (%). All designated national air quality automatic continuous monitoring stations measured the levels of air pollution [particulate matter (PM10 and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), ozone (O3)], and was documented by Environmental Protection Administration in Taiwan. We collected data on the levels of air pollution based on the participants' residential addresses.

RESULTS

In our study, we found that progressive and rapid progressive sperm motility significantly decreased annually (p < 0.05). In addition, increasing age influenced total sperm count, progressive sperm motility, rapid progressive sperm motility, and sperm with normal morphology (p < 0.05). Among different air pollution, we observed SO2 was associated with lower rapid progressive sperm motility and lower sperm with normal morphology (β = -0.103, p = 0.043; β = 0.118, p = 0.001, respectively). However, NO2 was associated with higher rapid progressive sperm motility and a high number of sperm with normal morphology (β = 0.129, p = 0.002; β = 0.127, p < 0.001, respectively).

CONCLUSIONS

The semen quality in southern Taiwan appears to have declined in recent years. The participant's age for semen analysis was most strongly associated with semen parameters, Moreover, a significant association between SO2 and NO2 levels and semen motility was observed, even after adjusting for multiple comparisons. Further study is required to analyze the dose-dependent effect of SO2 and NO2 on semen parameters.

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.

Impact of air pollution on the health of the older adults during physical activity and sedentary behavior: A systematic review

BACKGROUND

Air pollution, in addition to presenting health risks, can impact the practice of physical activity (PA) and sedentary behavior (SB) in older adults. This study analyzed the impact of air pollution on the health of older adults during PA and SB, through a systematic review.

METHODS

A keyword and reference search was performed in PubMed, SCOPUS, SPORTDiscus, and Web of Science. Predetermined selection criteria included study designs: interventions or experiments, retrospective or prospective cohort studies, cross-sectional studies and case-control studies; population: older adults aged 60 years or older; exposures: specific air pollutants (particulate matter (PM), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2), black carbon (CN), ultrafine particles (PU), nitrogen oxides (NOx) and biomass fuels) indoors and outdoors; and outcomes: physical activity and/or sedentary behavior.

RESULTS

The beneficial effects of PA were attenuated or harmed in 11 studies, showing negative impacts on the health of the older adults, mainly by PM2.5 pollutants. On the other hand, in 10 studies the effects of PA were greater than the negative effects of air pollutants, with a greater frequency in relation to PM2.5. In general, even the articles presenting controversial results suggest that practicing PA in polluted environments is more favorable to the health of older adults than remaining in SB.

DISCUSSION AND CONCLUSIONS

On the one hand, air pollution negatively impacted the health of the older adults during PA practices, while on the other hand, PA can mitigate the negative effects of pollutants on the health of older adults during the practices. Evidence shows that practicing PA in environments with low concentrations of pollutants can provide gains and reduce health risks. Remaining in SB in environments with high levels of air pollution worsens the health of older adults.

Is COPD mortality in South China causally linked to the long-term PM1 exposure? Evidence from a large community-based cohort

BACKGROUND

Long-term ambient particulate matter (PM) exposure has been found associated with chronic obstructive pulmonary disease (COPD) mortality in an increasing body of research. However, limited evidence was available on the potential causal links between PM1 and COPD mortality, especially in highly exposed areas.

OBJECTIVES

To examine the COPD mortality risk following long-term ambient PM1 exposure in south China.

METHODS

The cohort included 580,757 participants recruited during 2009-2015. Satellite-based annual concentrations of PM1 were estimated at a spatial resolution of 1 km × 1 km and assigned to each participant based on their residential addresses. We analyzed the potential causal links between time-varying PM1 exposure and COPD mortality using marginal structural cox models within causal frameworks. Stratified analyses were also performed to identify the potential susceptible groups.

RESULTS

The annual average PM1 concentration continuously decreased over time. After adjusting for confounders, each 1 μg/m3 increase in PM1 concentration corresponded to an 8.1 % (95% confidence interval: 6.4-9.9 %) increment in the risk of COPD mortality. The impact of PM1 was more pronounced among the elderly and those with low exercise frequency, with a 1.9-6.9 % higher risk than their counterparts. We further observed a 0.1-9.7 % greater risk among those who lived in lower greenness settings. Additionally, we observed higher effect estimates in participants with long-term low PM1 exposure compared to the general population.

CONCLUSIONS

COPD mortality risk significantly increased following long term ambient PM1 exposure, particularly among groups with certain demographics or long-term low exposure.

The Effects of Dance Interventions on Depression in Older Adults: A Meta-Analysis

Meta-analyses of the effects of dance on depressive symptoms in older adults have shown contradictory results, but few primary studies were included (5 and 8 studies). We aimed to examine the effects of dance on depressive symptoms in older adults aged 60 years and older and to examine the moderator effects of the source, participants, methods, and intervention characteristics. We included 23 primary studies that compared depressive symptoms across dance and comparison/control groups of older adults (72 ± 6.7 years old) and were written in English (N = 1,398) participants. Dance groups showed significantly less depressive symptoms post-intervention than comparison groups (ES = 0.66, 95% CI [0.42, 0.91], p < .001, I2 = 76.80%). South America and Australia showed the greatest effects. Using quasi-experimental designs showed significant effect sizes compared to using randomized designs. Only one quality indicator, intention-to-treat, influenced effect size. Dance might be used as an alternative treatment to improve depression.

Air pollution attenuated the benefits of physical activity on blood pressure: Evidence from a nationwide cross-sectional study

INTRODUCTION

Although physical activity (PA) has multiple health benefits, the inhaled dose of fine particulate matter (PM2.5) during PA may increase. The trade-off between harmful effects of PM2.5 exposure and protective effects of PA remain unclear. Our study aims to examine the joint effects of PA and PM2.5 exposure on blood pressure (BP) in Chinese adults.

METHODS

A total of 203,108 adults aged ≥ 18 years from the China Hypertension Survey study (2012-2015) were included. Individual-level PA was assessed as minutes of metabolic equivalent tasks per week (MET-min/week). The average weekly PM2.5 exposures were estimated by using a spatial resolution of 10 km, integrating multiple data sources, including monitoring values, satellite measurements and model simulations. BP was measured with a professional portable BP monitor. Generalized linear regressions were used to estimate joint associations and to further explore two-dimensional nonlinear associations.

RESULTS

The median PA and 4-week PM2.5 average exposures were 3213.0 MET-min/week and 47.8 μg/m3, respectively. PA was negatively associated with BP, while PM2.5 exposure was positively with BP. The associations between PA and systolic BP were significantly modified by PM2.5 exposure (Pinteraction < 0.001). Compared with inactive participants under low PM2.5 exposure, those with highest level of PA under low PM2.5 exposure had a 0.90 (95 % CI: 0.53, 1.26) mmHg decrease in systolic BP, whereas they had a 0.48 (95 % CI: 0.07, 0.89) mmHg increase under high PM2.5 exposure. When PM2.5 exposure was approximately > 25 μg/m3, the joint exposure to total PA and PM2.5 was associated with an increase in systolic BP.

CONCLUSIONS

The benefits of PA on BP were counteracted by high PM2.5 levels.

Potential causal links between long-term ambient particulate matter exposure and cardiovascular mortality: New evidence from a large community-based cohort in South China

BACKGROUND

Cardiovascular disease (CVD) mortality is associated with long-term particulate matter (PM) exposure. However, evidence from large, highly-exposed population cohort and observational-data-based causal inference approaches remains limited.

AIMS

We examined the potential causal links between PM exposure and the CVD mortality in South China.

METHODS

580,757 participants were recruited during 2009-2015 and followed up through 2020. Satellite-based annual concentrations of PM_2.5, PM₁₀, and PM_coarse (i.e., PM₁₀ - PM_2.5) at 1 km² spatial resolution were estimated and assigned to each participant. Marginal structural Cox models with time-varying covariates, adjusted using inverse probability weighting, were developed to evaluate the association between prolonged PM exposure and CVD mortality.

RESULTS

For overall CVD mortality, the hazard ratios and 95% confidence interval for each 1 μg/m³ increase in the annual average concentration of PM_2.5, PM₁₀, and PM_coarse were 1.033 (1.028-1.037), 1.028 (1.024-1.032), and 1.022 (1.012-1.033), respectively. All three PMs were linked to a higher mortality risk for myocardial infarction and ischemic heart disease (IHD). The mortality risk of chronic IHD and hypertension was linked to PM_2.5 and PM₁₀. Significant association between PM_coarse and other heart disease mortality was also observed. The older, women, less-educated participants, or inactive participants exhibited particularly higher susceptibility. Participants who were generally exposed to PM₁₀ concentrations below 70 μg/m³ were more vulnerable to PM_2.5-, PM₁₀- and PM_coarse-CVD mortality risks.

CONCLUSION

This large cohort study provides evidence for the potential causal links between increased CVD mortality and ambient PM exposure, as well as socio-demographics linked to the highest vulnerability.

Long-term exposure to ambient PM2·5, active commuting, and farming activity and cardiovascular disease risk in adults in China: a prospective cohort study

BACKGROUND

Increased physical activity is associated with a reduced risk of cardiovascular disease, but outdoor physical activity can be accompanied by increased inhalation of fine particulate matter (PM2·5). The extent to which long-term exposure to PM2·5 can offset the cardiovascular benefits of physical activity is unknown. We aimed to evaluate whether the associations between active commuting or farming activity and incident risks of cerebrovascular disease and ischaemic heart disease were consistent between populations with different ambient PM2·5 exposures.

METHODS

We did a prospective cohort study using data from people aged 30-79 years without cardiovascular disease at baseline from the China Kadoorie Biobank (CKB). Active commuting and farming activity were assessed at baseline using questionnaires. A high-resolution (1 × 1 km) satellite-based model was used to estimate annual average PM2·5 exposure during the study period. Participants were stratified according to PM2·5 exposure (54 μg/m3 or greater vs less than 54 μg/m3). Hazard ratios (HRs) and 95% CIs for incident cerebrovascular disease and ischaemic heart disease by active commuting and farming activity were estimated using Cox proportional hazard models. Effect modifications by PM2·5 exposure were tested by likelihood ratio tests. Analyses were restricted to the period from Jan 1, 2005, to Dec 31, 2017.

FINDINGS

Between June 25, 2004, and July 15, 2008, 512 725 people were enrolled in the CKB cohort. 322 399 eligible participants completed the baseline survey and were included in the analysis of active commuting (118 274 non-farmers and 204 125 farmers). Among 204 125 farmers, 2985 reported no farming time and 201 140 were included in the farming activity analysis. During a median follow-up of 11 years, 39 514 cerebrovascular disease cases and 22 313 ischaemic heart disease cases were newly identified. Among non-farmers with exposure to annual average PM2·5 concentrations of less than 54 μg/m3, increased active commuting was associated with lower risks of cerebrovascular disease (highest active commuting vs lowest active commuting HR 0·70, 95% CI 0·65-0·76) and ischaemic heart disease (0·60, 0·54-0·66). However, among non-farmers with exposure to annual average PM2·5 concentrations of 54 μg/m3 or greater, there was no association between active commuting and cerebrovascular disease or ischaemic heart disease. Among farmers with exposure to annual average PM2·5 concentrations of less than 54 μg/m3, increased active commuting (highest active commuting vs lowest active commuting HR 0·77, 95% CI 0·63-0·93) and increased farming activity (highest activity vs lowest activity HR 0·85, 95% CI 0·79-0·92) were both associated with a lower cerebrovascular disease risk. However, among farmers with exposure to annual average PM2·5 concentrations of 54 μg/m3 or greater, increases in active commuting (highest active commuting vs lowest active commuting HR 1·12, 95% CI 1·05-1·19) and farming activity (highest activity vs lowest activity HR 1·18, 95% CI 1·09-1·28) were associated with an elevated cerebrovascular disease risk. The above associations differed significantly between PM2·5 strata (all interaction p values <0·0001).

INTERPRETATION

For participants with long-term exposure to higher ambient PM2·5 concentrations, the cardiovascular benefits of active commuting and farming activity were significantly attenuated. Higher levels of active commuting and farming activity even increased the cerebrovascular disease risk among farmers with exposure to annual average PM2·5 concentrations of 54 μg/m3 or greater.

FUNDING

National Natural Science Foundation of China, National Key Research and Development Program of China, Kadoorie Charitable Foundation, UK Wellcome Trust.

Long-term exposure to particulate matter on cardiovascular and respiratory diseases in low- and middle-income countries: A systematic review and meta-analysis

Background

Long-term exposure to particulate matter (PM) has essential and profound effects on human health, but most current studies focus on high-income countries. Evidence of the correlations between PM and health effects in low- and middle-income countries (LMICs), especially the risk factor PM1 (particles &lt; 1 μm in size), remains unclear.

Objective

To explore the effects of long-term exposure to particulate matter on the morbidity and mortality of cardiovascular and respiratory diseases in LMICs.

Methods

A systematic search was conducted in the PubMed, Web of Science, and Embase databases from inception to May 1, 2022. Cohort studies and case-control studies that examine the effects of PM1, PM2.5, and PM10 on the morbidity and mortality of cardiovascular and respiratory diseases in LMICs were included. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Outcomes were analyzed via a random effects model and are reported as the relative risk (RR) with 95% CI.

Results

Of the 1,978 studies that were identified, 38 met all the eligibility criteria. The studies indicated that long-term exposure to PM2.5, PM10, and PM1 was associated with cardiovascular and respiratory diseases: (1) Long-term exposure to PM2.5 was associated with an increased risk of cardiovascular morbidity (RR per 1.11 μg/m3, 95% CI: 1.05, 1.17) and mortality (RR per 1.10 μg/m3, 95% CI: 1.06, 1.14) and was significantly associated with respiratory mortality (RR 1.31, 95% CI: 1.25, 1.38) and morbidity (RR 1.08, 95% CI: 1.02, 1.04); (2) An increased risk of respiratory mortality was observed in the elderly (65+ years) (RR 1.21, 95% CI: 1.00, 1.47) with long-term exposure to PM2.5; (3) Long-term exposure to PM10 was associated with cardiovascular morbidity (RR 1.07, 95% CI 1.01, 1.13), respiratory morbidity (RR 1.43, 95% CI: 1.21, 1.69) and respiratory mortality (RR 1.28, 95% CI 1.10, 1.49); (4) A significant association between long-term exposure to PM1 and cardiovascular disease was also observed.

Conclusions

Long-term exposure to PM2.5, PM10 and PM1 was all related to cardiovascular and respiratory disease events. PM2.5 had a greater effect than PM10, especially on respiratory diseases, and the risk of respiratory mortality was significantly higher for LMICs than high-income countries. More studies are needed to confirm the effect of PM1 on cardiovascular and respiratory diseases.

Are associations of leisure-time physical activity with mortality attenuated by high levels of chronic ambient fine particulate matter (PM2.5) in older adults? A prospective cohort study

BACKGROUND AND PURPOSE

Although leisure-time physical activity (PA) has established health benefits in older adults, it is equivocal if exercising in environments with high levels of PM_2.5 concentrations is equally beneficial for them. To explore the independent and joint associations of ambient PM_2.5 and PA with all-cause mortality among adults aged 60 or older and to assess the modifying effect of age (60-74 years vs. 75+ years) on the joint associations.

METHODS

A prospective cohort study based on the MJ Cohort repeat examinations (2005-2016) and the Taiwan Air Quality Monitoring Network and death registry linkages (2005-2022). We included MJ Cohort participants aged 60 or more at baseline who attended the health check-ups at least twice (n = 21,760). Metabolic equivalent hours per week (MET-h/week) of leisure-time PA were computed. Multivariable adjusted associations were examined using time-varying Cox proportional hazard models.

RESULTS

There were 3539 all-cause deaths over a mean follow-up of 12.81 (SD = 3.67) years. Ambient PM_2.5 and physical inactivity are both independently associated with all-cause mortality. The joint associations of PA and PM_2.5 concentrations with all-cause mortality differed in the young-old (60-74 years) and the older-old (75+ years) (P for interaction = 0.01); Higher levels of long-term PM_2.5 exposures (≥25 μg/m³) had little influence on the associations between PA and mortality in the young-old (HR = 0.68 (0.56-0.83) and HR = 0.72 (0.59-0.88) for participants with 7.5-<15 and 15+ MET-h/week respectively) but eliminated associations between exposure and outcome in the older-old (HR = 0.91 (0.69-01.21) and HR = 1.02 (0.76-1.38) for participants with 7.5-<15 and 15+ MET-h/week).

CONCLUSION

Long-term exposures to higher PM_2.5 concentrations may eliminate the beneficial associations of PA with all-cause mortality among adults aged 75 and over.

Effects of Air Pollution on the Health of Older Adults during Physical Activities: Mapping Review

Atmospheric pollutants present environmental threats to health and have been investigated in different environments, such as highways, squares, parks, and gyms. These environments are frequented by older adults, who are considered fragile to the harmful impacts of pollution present in the air. The aim was to analyze the state of the art on the effects of air pollution on the health of older adults during physical activities (PAs) through a mapping review. The search was performed in PubMed, Web of Science, Scopus, and Cinahl databases until June 2022. Of the 10,109 studies initially identified, 58 met the inclusion criteria. The most investigated health outcome was cardiovascular disease, followed by respiratory outcomes. Particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3) were the most investigated pollutants. Of the 75 health outcomes investigated, in 29, air pollution had harmful effects on the health of the older adults during the practice of PA, more frequently in cardiovascular diseases. In 25 outcomes, the beneficial effects of PA to the health of the older adults remained, despite exposure to high and low concentrations of pollutants, most often in terms of mental disorders. We conclude that poor air quality is a harmful factor for the health of older adults during the practice of PAs, more frequently in cardiovascular and respiratory diseases. On the other hand, for mental-health-related outcomes (depression and cognition), in most studies, the beneficial effects of PA in older adults were maintained, even after exposure to pollutants.

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.

Association between Air Pollution and Physical Activity and Sedentary Behavior among Adults Aged 60 Years or Older in China: A Cross-Sectional Study

BACKGROUND

Exposure to air pollution is associated with an increased risk of all-cause mortality in older adults. Promoting physical activity (PA) and avoiding sedentary behavior (SB) serve as key strategies to maintain and improve human health. However, ambient air pollution can adversely affect PA and SB, increasing the risks of health problems. This study aimed to visualize national spatial patterns of average AQI concentration, PA, and SB distributions and to examine the associations between air pollution and PA and SB in a national sample of Chinese older adults aged 60 years or older.

METHODS

We analyzed the data of the China Longitudinal Aging Social Survey 2020 (CLASS 2020), which sampled 11,399 older men and women from 30 cities in China. Moderate, vigorous, and light PA and SB were measured using the Chinese version of the International Physical Activity Questionnaire-Short Form (IPAQ-C). The environmental measures included the average hourly air quality index (AQI), PM_2.5, PM₁₀, and NO₂ (µg/m³). The data were analyzed using multivariable linear regression.

RESULTS

Increases in the standard deviations (±SD) of AQI, PM_2.5, PM₁₀, and NO₂ concentrations were associated with decreases in MVPA per week of -2.34 (95%CI = -3.36, -1.32), -2.58 (95%CI = -3.61, -1.55), -1.96 (95%CI = -3.05, -0.08), and -1.19 (95%CI = -2.06, -0.31) and decreases in LPA per week of -6.06 (95%CI = -7.15, -4.97), -4.86 (95%CI = -5.88, -3.85), -4.78 (95%CI = -5.89, -3.68), and -4.59 (95%CI = -5.57, -3.61) h/week, respectively. Increases in one SD of AQI, PM_2.5, PM₁₀, and NO₂ were associated with increases in SB per week of 1.32 (95%CI = 0.77, 1.88), 0.62 (95%CI = 0.09, 1.14), 1.03 (95%CI = 0.48, 1.59), and 0.98 (95%CI = 0.46, 1.49) h/week, respectively.

CONCLUSIONS

The spatial distributions of the average AQI concentration, MVPA, LPA, and SB are useful and allow environmental and health policymakers to identify the areas with the highest priority air pollution environmental equality concerns. AQI was positively associated with MVPA and LPA, and it was negatively associated with SB among older adults. AQI, PM_2.5, PM₁₀, and NO₂ were hardly associated with women's average time spent engaged in MVPA. Region-specific and multi-level health policy options are needed to reduce ambient air pollution by taking different types of pollutants into account in order to avoid changes in PA and SB in this population, especially in locations with high air pollution concentrations.

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.

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.

Longitudinal associations between metabolites and long-term exposure to ambient air pollution: Results from the KORA cohort study

BACKGROUND

Long-term exposure to air pollution has been associated with cardiopulmonary diseases, while the underlying mechanisms remain unclear.

OBJECTIVES

To investigate changes in serum metabolites associated with long-term exposure to air pollution and explore the susceptibility characteristics.

METHODS

We used data from the German population-based Cooperative Health Research in the Region of Augsburg (KORA) S4 survey (1999-2001) and two follow-up examinations (F4: 2006-08 and FF4: 2013-14). Mass-spectrometry-based targeted metabolomics was used to quantify metabolites among serum samples. Only participants with repeated metabolites measurements were included in the current analysis. Land-use regression (LUR) models were used to estimate annual average concentrations of ultrafine particles, particulate matter (PM) with an aerodynamic diameter less than 10 μm (PM₁₀), coarse particles (PM_coarse), fine particles, PM_2.5 absorbance (a proxy of elemental carbon related to traffic exhaust, PM_2.5abs), nitrogen oxides (NO₂, NO_x), and ozone at individuals' residences. We applied confounder-adjusted mixed-effects regression models to examine the associations between long-term exposure to air pollution and metabolites.

RESULTS

Among 9,620 observations from 4,261 KORA participants, we included 5,772 (60.0%) observations from 2,583 (60.6%) participants in this analysis. Out of 108 metabolites that passed stringent quality control across three study points in time, we identified nine significant negative associations between phosphatidylcholines (PCs) and ambient pollutants at a Benjamini-Hochberg false discovery rate (FDR) corrected p-value < 0.05. The strongest association was seen for an increase of 0.27 μg/m³ (interquartile range) in PM_2.5abs and decreased phosphatidylcholine acyl-alkyl C36:3 (PC ae C36:3) concentrations [percent change in the geometric mean: -2.5% (95% confidence interval: -3.6%, -1.5%)].

CONCLUSIONS

Our study suggested that long-term exposure to air pollution is associated with metabolic alterations, particularly in PCs with unsaturated long-chain fatty acids. These findings might provide new insights into potential mechanisms for air pollution-related adverse outcomes.

The Weight of Place: Built Environment Correlates of Obesity and Diabetes

In recent decades, the prevalence of obesity and diabetes has risen substantially in North America and worldwide. To address these dual epidemics, researchers and policymakers alike have been searching for effective means to promote healthy lifestyles at a population level. As a consequence, there has been a proliferation of research examining how the "built" environment in which we live influences physical activity levels, by promoting active forms of transportation, such as walking and cycling, over passive ones, such as car use. Shifting the transportation choices of local residents may mean that more members of the population can participate in physical activity during their daily routine without structured exercise programs. Increasingly, this line of research has considered the downstream metabolic consequences of the environment in which we live, raising the possibility that "healthier" community designs could help mitigate the rise in obesity and diabetes prevalence. This review discusses the evidence examining the relationship between the built environment, physical activity, and obesity-related diseases. We also consider how other environmental factors may interact with the built environment to influence metabolic health, highlighting challenges in understanding causal relationships in this area of research.

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 (PM2.5) 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) PM2.5 estimates were generated using a satellite-based model.

RESULTS

During 413,516 person-years of follow-up, 12,100 incident hypertension cases were identified. PM2.5 significantly modified the relationship between PA and hypertension incidence (pinteraction < 0.001). Increased PA volume was negatively associated with incident hypertension in the low PM2.5 stratum (<59.8 μg/m3, ptrend < 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 PM2.5 stratum (≥59.8 μg/m3, ptrend = 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 PM2.5, but a 17% (95%CI: 4%-33%) increased risk for those with high PM2.5 levels.

CONCLUSION

PA was associated with a reduced risk of hypertension only among participants with low PM2.5 exposure. Our findings recommended regular PA to prevent hypertension in less polluted regions and reinforced the importance of air quality improvement.

Habitual Exercise, Air Pollution, and Pneumonia Mortality: A Longitudinal Cohort Study of Approximately 0.4 Million Adults

In this study, we aimed to examine the combined associations of particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) and habitual exercise with pneumonia mortality. We included 384,130 persons aged ≥18 years from Taiwan, Republic of China, during 2001-2016. We followed participants until May 31, 2019, to obtain information on vital status. A time-dependent Cox regression model was used for statistical analysis. We found that risks of pneumonia mortality were reduced by 55% (hazard ratio (HR) = 0.45, 95% confidence interval (CI): 0.36, 0.55) and 36% (HR = 0.64, 95% CI: 0.52, 0.80) in participants who engaged in high and moderate levels of exercise, respectively, as compared with inactive persons. By contrast, each 10-μg/m3 increase in chronic PM2.5 exposure was associated with a 30% (HR = 1.30, 95% CI: 1.17, 1.45) higher risk of pneumonia mortality. Risk of pneumonia death was 72% lower (HR = 0.28, 95% CI: 0.20, 0.41) for persons with a high exercise level and a low PM2.5 level. Lower risk of pneumonia mortality was associated with both higher exercise and lower PM2.5 air pollution levels. For adults exposed to different levels of PM2.5, exercise benefits remained. Our findings suggest that engaging in exercise is a safe and effective strategy for alleviating the burden of pneumonia mortality, even for people who reside in a moderately polluted area.

Association of Physical Activity with Incidence of Dementia Is Attenuated by Air Pollution

INTRODUCTION

Physical activity (PA) is recognized as one of the key lifestyle behaviors that reduces risk of developing dementia late in life. However, PA also leads to increased respiration, and in areas with high levels of air pollution, PA may increase exposure to pollutants linked with higher risk of developing dementia. Here, we investigate whether air pollution attenuates the association between PA and dementia risk.

METHODS

This prospective cohort study included 35,562 adults 60 yrs and older from the UK Biobank. Average acceleration magnitude (ACCave) from wrist-worn accelerometers was used to assess PA levels. Air pollution levels (NO, NO2, PM10, PM2.5, PM2.5-10, and PM2.5 absorbance) were estimated with land use regression methods. Incident all-cause dementia was derived from inpatient hospital records and death registry data.

RESULTS

In adjusted models, ACCave was associated with reduced risk of developing dementia (HR = 0.71, 95% confidence interval [CI] = 0.60-0.83), whereas air pollution variables were not associated with dementia risk. There were significant interactions between ACCave and PM2.5 (HRinteraction = 1.33, 95% CI = 1.13-1.57) and PM2.5 absorbance (HRinteraction = 1.24, 95% CI = 1.07-1.45) on incident dementia. At the lowest tertiles of pollution, ACCave was associated with reduced risk of incident dementia (HRPM 2.5 = 0.66, 95% CI = 0.49-0.91; HRPM 2.5 absorbance = 0.60, 95% CI = 0.44-0.81). At the highest tertiles of these pollutants, there was no significant association of ACCave with incident dementia (HRPM 2.5 = 0.88, 95% CI = 0.68-1.14; HRPM 2.5 absorbance = 0.79, 95% CI = 0.60-1.04).

CONCLUSIONS

PA is associated with reduced risk of developing all-cause dementia. However, exposure to even moderate levels of air pollution attenuates the benefits of PA on risk of dementia.

Mortality risk associated with greenness, air pollution, and physical activity in a representative U.S. cohort

Several cohort studies suggest greenness is associated with decreased mortality risk. Potential confounding by or interactions between physical activity and air pollution remains unclear. This study evaluates associations of greenness, air pollution, and physical activity with mortality risk and investigates confounding and effect modification across these key risk factors. National Health Interview Survey (NHIS) data covering 1997-2014 were linked to the National Death Index to generate a cohort of 403,748 individuals with 39,528 deaths. Greenness, represented by census-tract Normalized Difference Vegetation Index (NDVI) for the seasonal period of May-October, was averaged over the years 2003-2016. Air pollution was estimated by census-tract level PM_2.5 concentrations from 1999 to 2015. Cox Proportional Hazard Models were used to estimate hazard ratios (HR) for differences in greenness, air pollution, and physical activity. Alternative models that evaluated potential confounding and stratified models that evaluated effect modification were examined. Mortality risks were associated with PM_2.5 (HR = 1.14, 95% CI: 1.09-1.19 per 10 μg/m³) and physical inactivity (1.49, 1.44-1.54 relative to sufficiently active), but not with greenness (1.01, 0.99-1.03 per IQR). The PM_2.5-mortality association was mitigated at high levels of greenness (1.05, 0.91-1.22). There was no strong evidence of confounding between air pollution, physical activity, and greenness. However, stratified analysis suggested effect modification for PM_2.5 and NDVI by physical activity. A significant protective greenness-mortality association was observed for only highly active individuals (0.91, 0.86-0.96). Also, relatively high PM_2.5-mortality HRs were observed for more physically active individuals (1.25, 1.12-1.40). PM_2.5 air pollution and physical inactivity are robustly associated with mortality risk. Greenness may be most beneficial and air pollution relatively harmful to highly active individuals. This analysis provides evidence that, in addition to not smoking, being physically active and living in a clean, green environment contributes to improved health and reduced risk of mortality.

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.

Gender Differences in the Associations Between Physical Activity, Smartphone Use, and Weight Stigma

Background

Physical activity (PA) is important for health. However, there is little evidence on how weight stigma, time spent on sedentary activities (including smartphone, social media, online learning), time spent on outdoor activity, and nomophobia associate with PA among Chinese individuals with consideration of gender. The present study examined the aforementioned associations in the COVID-19 pandemic era.

Methods

University students (N = 3,135; 1,798 females, 1,337 males) with a mean age of 19.65 years (SD = 2.38) years completed an online survey from November to December, 2021. The online survey assessed weight stigma (using the Perceived Weight Stigma Scale and Weight Bias Internalization Scale), PA (using the International Physical Activity Questionnaire Short Form), time spent on different activities (using self-designed items for time on smartphone, outdoor activity, social media, and online learning), and nomophobia (using the Nomophobia Questionnaire). Parallel mediation models were constructed (dependent variable: PA; mediators: perceived weight stigma, weight-related self-stigma, time spent on smartphone, time spent on outdoor activity, time spent on social media, and time spent online learning; independent variable: nomophobia) and evaluated using Hayes' Process Macro Model 4 (IBM SPSS 20.0).

Results

Weight-related self-stigma (β = −0.06; p = 0.03), time spent on outdoor activity (β = 0.21; p < 0.001), time spent on social media (β = 0.07; p = 0.02), time spent on online learning (β = 0.06; p = 0.03), and nomophobia (β = −0.07; p = 0.01) were all significant factors explaining the PA among female participants. Perceived weight stigma (β = −0.07; p = 0.01), time spent on outdoor activity (β = 0.27; p < 0.001), and time spent on online learning (β = 0.10; p = 0.002) were all significant factors explaining PA among male participants.

Conclusion

Chinese healthcare providers should design programs on weight stigma reduction and outdoor activity improvement to enhance PA among university students.

Long-term exposure to air pollution, habitual physical activity and risk of non-alcoholic fatty liver disease: A prospective cohort study

BACKGROUND

Emerging studies suggest a positive association between air pollution exposure and risk of non-alcoholic fatty liver disease (NAFLD), however, the combined effects of long-term exposure to air pollution, physical activity (PA), and risk of NAFLD is unclear.

METHODS

We included 58,026 Taiwan residents who received a standard medical screening program between 2001 and 2016. Levels of fine particulate matter (PM_2.5) at each participant's residential address were estimated using multiple satellite-based aerosol optical depth data combined with a chemical transport model. PA volume was calculated as hours of metabolic equivalent tasks per week (MET-h/week) based on a standard self-administered questionnaire. Incident NAFLD was defined as the first occurrence of a fatty liver index (FLI) value > 30 or a hepatic steatosis index (HSI) value > 36 in participants without NAFLD at the baseline. Time-varying Cox regression was used to evaluate the combined effects of PA and PM_2.5.

RESULTS

Exposure to PM_2.5 was positively associated with NAFLD. A 1 μg/m³ increase in PM_2.5 above 23.5 μg/m³ was associated with a hazard ratio (HR) of 1.06 (95% CI: 1.04, 1.09) and 1.05 (95% CI: 1.03, 1.07) for NAFLD identified by FLI and HSI, respectively. Performing PA was inversely associated with NAFLD. Compared with participants in high PM_2.5 [≥ 27.5 μg/m³]-very low PA [< 3.75 MET-h/week] group, low PM_2.5 [< 23.5 μg/m³]-very high PA [≥ 25.50 MET-h/week] group had a 57% (95% CI: 50%, 63%) and 42% (95% CI: 33%, 50%) lower risk of NAFLD defined by FLI and HSI, respectively. We found no evidence of any additive or multiplicative interaction between PA and PM_2.5.

CONCLUSION

Long-term PM_2.5 exposure was positively associated with NAFLD, whereas performing PA was inversely associated with NAFLD. The benefits of PA on NAFLD remained stable in participants exposed to various PM_2.5 levels.

Health Effects of Long-Term Exposure to Ambient PM2.5 in Asia-Pacific: a Systematic Review of Cohort Studies

Abstract

Purpose of Review

Health effects of long-term exposure to ambient PM_2.5 vary with regions, and 75% of the deaths attributable to PM_2.5 were estimated in Asia-Pacific in 2017. This systematic review aims to summarize the existing evidence from cohort studies on health effects of long-term exposure to ambient PM_2.5 in Asia-Pacific.

Recent Findings

In Asia-Pacific, 60 cohort studies were conducted in Australia, Mainland China, Hong Kong, Taiwan, and South Korea. They consistently supported associations of long-term exposure to PM_2.5 with increased all-cause/non-accidental and cardiovascular mortality as well as with incidence of cardiovascular diseases, type 2 diabetes mellitus, kidney diseases, and chronic obstructive pulmonary disease. Evidence for other health effects was limited. Inequalities were identified in PM_2.5-health associations.

Summary

To optimize air pollution control and public health prevention, further studies need to assess the health effects of long-term PM_2.5 exposure in understudied regions, the health effects of long-term PM_2.5 exposure on mortality and risk of type 2 diabetes mellitus, renal diseases, dementia and lung cancer, and inequalities in PM_2.5-health associations. Study design, especially exposure assessment methods, should be improved.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40572-022-00344-w.

Association between long-term exposure to PM2.5 and hypertension: A systematic review and meta-analysis of observational studies

BACKGROUND

Numerous studies have examined the association between long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) and hypertension. However, the results are inconsistent.

OBJECTIVES

Considering the limitations of previous meta-analyses and the publication of many new studies in recent years, we conducted this meta-analysis to assess the relationship between long-term PM_2.5 exposure and the incidence and prevalence of hypertension in a healthy population.

METHODS

We searched PubMed, Web of Science, Embase, and Scopus for relevant studies published until April 2, 2021 and reviewed the reference lists of previous reviews. A total of 28 observational studies reporting RR or OR with 95% CI for the association between long-term PM_2.5 exposure and the risk of hypertension were included.

RESULTS

After the sensitivity analysis, we excluded one study with a high degree of heterogeneity, resulting in 27 studies and 28 independent reports. Approximately 42 million participants were involved, and the cases of hypertension in cohort and cross-sectional studies were 508,749 and 1,793,003, respectively. The meta-analysis showed that each 10 μg/m³ increment in PM_2.5 was significantly associated with the risks of hypertension incidence (RR = 1.21, 95% CI: 1.07, 1.35) and prevalence (OR = 1.06, 95% CI: 1.03, 1.09). Subgroup analyses showed that occupational exposure had a significant effect on the association of PM_2.5 and hypertension incidence (p for interaction = 0.042) and that the PM_2.5 concentration level and physical activity had a noticeable effect on the association of PM_2.5 and hypertension prevalence (p for interaction = 0.005; p for interaction = 0.022).

CONCLUSIONS

A significantly positive correlation was observed between long-term PM_2.5 exposure and risks of hypertension incidence and prevalence, and a high PM_2.5 concentration resulted in an increased risk of hypertension.

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.

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.

Frailty Related to the Exposure to Particulate Matter and Ozone: The Korean Frailty and Aging Cohort Study

This study aims to identify the association between the concentration of particulate matter <2.5 μm (PM_2.5), <10 μm (PM₁₀), and ozone (O₃) and frailty. The Korean Frailty Scale (KFS, 0-6 points) assessing physical, psychological, and social frailty, was applied to 2912 community-dwelling older adults between April 2016 and December 2017. Daily average concentrations of PM_2.5, PM₁₀, and O₃ (2015-2017) were obtained and matched with the residential areas. The frailty risk associated with exposure to PM_2.5, PM₁₀, and O₃ was evaluated using multiple logistic regression after adjusting for age, sex, BMI, lifestyle, socioeconomic status, and comorbidity. Participants were categorized into robust (0 points, 28.7%), pre-frail (1-2 points, 50.1%), and frail (≥3 points, 21.2%) groups. Each 1 μg/m³ increase of PM_2.5 and PM₁₀ increased the odds ratios (ORs) and 95% confidence intervals (CIs) of the frail group compared to the robust group: 1.055 (1.002, 1.112) and 1.095 (1.060, 1.131), and the pre-frail group: 1.053 (1.017, 1.090) and 1.062 (1.037, 1.087), respectively. Each 1-ppb increase of O₃ increased the OR (95% CI) of the frail group: 1.041 (1.023, 1.059) and the pre-frail group: 1.005 (0.985, 1.025). PM_2.5, PM₁₀, and O₃ may be associated dose-dependently with the frailty.

Physical Activity in Polluted Air-Net Benefit or Harm to Cardiovascular Health? A Comprehensive Review

Both exposure to higher levels of polluted air and physical inactivity are crucial risk factors for the development and progression of major noncommunicable diseases and, in particular, of cardiovascular disease. In this context, the World Health Organization estimated 4.2 and 3.2 million global deaths per year in response to ambient air pollution and insufficient physical activity, respectively. While regular physical activity is well known to improve general health, it may also increase the uptake and deposit of air pollutants in the lungs/airways and circulation, due to increased breathing frequency and minute ventilation, thus increasing the risk of cardiovascular disease. Thus, determining the tradeoff between the health benefits of physical activity and the potential harmful effects of increased exposure to air pollution during physical activity has important public health consequences. In the present comprehensive review, we analyzed evidence from human and animal studies on the combined effects of physical activity and air pollution on cardiovascular and other health outcomes. We further report on pathophysiological mechanisms underlying air pollution exposure, as well as the protective effects of physical activity with a focus on oxidative stress and inflammation. Lastly, we provide mitigation strategies and practical recommendations for physical activity in areas with polluted air.

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.

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 short-term fine particulate matter exposure with pulmonary function in populations at intermediate to high-risk of cardiovascular disease: A panel study in three Chinese cities

BACKGROUND

Decline in pulmonary function contributes to increasing cardiovascular disease (CVD) risk. Although adverse effects of short-term exposure to fine particulate matter (PM_2.5) on pulmonary function have been recognized in healthy people or patients with respiratory disease, these results were not well illustrated among people with elevated CVD risk.

MATERIALS AND METHODS

A panel study was conducted in three Chinese cities with three repeated visits among populations at intermediate to high-risk of CVD, defined as treated hypertension patients or those with blood pressure ≥ 130/80 mmHg, who met any of the three conditions including abdominal obesity, dyslipidemia, and diabetes mellitus. Individualized PM_2.5 exposure and pulmonary function were measured during each seasonal visit. Linear mixed-effect models were applied to analyze the associations of PM_2.5 concentrations with pulmonary function indicators, including forced expiratory volume in 1 s (FEV₁), FEV₁/forced vital capacity (FVC), maximal mid-expiratory flow (MMF), and peak expiratory flow (PEF).

RESULTS

Short-term PM_2.5 exposure was significantly associated with decreased pulmonary function and an increment of 10 μg/m³ in PM_2.5 concentrations during lag 12-24 hour was associated with declines of 41.7 ml/s (95% confidence interval [CI]: 7.7-75.7), 0.35% (95% CI: 0.01, 0.69), and 20.9 ml/s (95% CI: 0.5-41.3) for PEF, FEV₁/FVC, and MMF, respectively. Results from stratified and sensitivity analyses were generally similar with the overall findings, while the adverse effects of PM_2.5 on pulmonary functions were more pronounced in those who were physically inactive.

CONCLUSIONS

This study first identified short-term exposure to PM_2.5 was associated with impaired pulmonary function and physical activity might attenuate the adverse effects of PM_2.5 among populations at intermediate to high-risk of CVD. These findings provide new robust evidence on health effects of air pollution and call for effective prevention measures among people at CVD risk.

Benefits of active commuting on cardiovascular health modified by ambient fine particulate matter in China: A prospective cohort study

BACKGROUND

Active commuting as a contributor to daily physical activity is beneficial for cardiovascular health, but leads to more chances of exposure to ambient air pollution. This study aimed to investigate associations between active commuting to work with cardiovascular disease (CVD), mortality and life expectancy among general Chinese adults, and to further evaluate the modification effect of fine particulate matter (PM2.5) exposure on these associations.

METHODS

We included 76,176 Chinese adults without CVD from three large cohorts of the Prediction for Atherosclerotic Cardiovascular Disease Risk in China project. Information about commuting mode and physical activity were collected by unified questionnaire. Satellite-based PM2.5 concentrations at 1-km spatial resolution was used for estimating PM2.5 exposure of participants. Hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD incidence, mortality and all-cause mortality were estimated using Cox proportional hazards regression models. Multiplicative interaction term of commuting mode and PM2.5 level was tested to investigate potential effect modification.

RESULTS

During 448,499 person-years of follow-up, 2230 CVD events and 2777 all-cause deaths were recorded. Compared with the non-active commuters, the multivariable-adjusted HRs (95% CIs) of CVD incidence and all-cause mortality were 0.95(0.85-1.05) and 0.79(0.72-0.87) for walking commuters, respectively. Corresponding HRs (95% CIs) for cycling commuters were 0.71(0.62-0.82) and 0.67(0.59-0.76). Active commuters over 45 years old were estimated to have more CVD-free years and life expectancy than non-active commuters under lower PM2.5 concentration. However, these beneficial effects of active commuting were alleviated or counteracted by long-term exposure to high PM2.5 concentration. Significant multiplicative interaction of commuting mode and PM2.5 level was showed in all-cause mortality, with the lowest risk observed in cycling participants exposed to lower level of PM2.5.

CONCLUSIONS

Active commuting was associated with lower risk of CVD, all-cause mortality, and longer life expectancy among Chinese adults under ambient settings with lower PM2.5 level. It will be valuable to encourage active commuting among adults and develop stringent strategies on ambient PM2.5 pollution control for prevention of CVD and prolongation of life expectancy.

Effects of air pollution and habitual exercise on the risk of death: a longitudinal cohort study

Background:

Exercise may exacerbate the adverse health effects of air pollution by increasing the inhalation of air pollutants. We investigated the combined effects of long-term exposure to fine particle matter (PM_2.5) and habitual exercise on deaths from natural causes in Taiwan.

Methods:

We recruited 384 130 adults (aged ≥ 18 yr) with 842 394 medical examination records between 2001 and 2016, and followed all participants until May 31, 2019. We obtained vital data from the National Death Registry of Taiwan. We estimated PM_2.5 exposure using a satellite-based spatiotemporal model, and collected information on exercise habits using a standard self-administered questionnaire. We analyzed the data using a Cox regression model with time-dependent covariates.

Results:

A higher level of habitual exercise was associated with a lower risk of death from natural causes, compared with inactivity (hazard ratio [HR] 0.84, 95% confidence interval [CI] 0.80–0.88 for the moderate exercise group; HR 0.65, 95% CI 0.62–0.68 for the high exercise groups), whereas a higher PM_2.5 exposure was associated with a higher risk of death from natural causes compared with lower exposure (HR 1.02, 95% CI 0.98–1.07, and HR 1.15, 95% CI 1.10–1.20, for the moderate and high PM_2.5 exposure groups, respectively). Compared with inactive adults with high PM_2.5 exposure, adults with high levels of habitual exercise and low PM_2.5 exposure had a substantially lower risk of death from natural causes. We found a minor, but statistically significant, interaction effect between exercise and PM_2.5 exposure on risk of death (HR 1.03 95% CI 1.01–1.06). Subgroup analyses, stratified by PM_2.5 categories, suggested that moderate and high levels of exercise were associated with a lower risk of death in each PM_2.5 stratum, compared with inactivity.

Interpretation:

Increased levels of exercise and reduced PM_2.5 exposure are associated with a lower risk of death from natural causes. Habitual exercise can reduce risk regardless of the levels of PM_2.5 exposure. Our results suggest that exercise is a safe health improvement strategy, even for people residing in relatively polluted regions.

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.

Lower-than-standard particulate matter air pollution reduced life expectancy in Hong Kong: A time-series analysis of 8.5 million years of life lost

BACKGROUND

Increasing studies reported increased mortality risk associated with exposure to lower-than-standard air pollution. This study aimed to investigate mortality burden and life expectancy loss due to lower-than-standard particulate matter air pollution in Hong Kong, China.

METHODS

We obtained 17-year (2000-2016) daily time-series data on mortality, particulate matters with aerodynamic diameters <2.5 μm (PM_2.5) and <10 μm (PM₁₀). We applied a distributed lag non-linear model to fit the association of years of life lost (YLL) with PM_2.5 and PM₁₀. Total YLL attributable to PM_2.5 and PM₁₀ concentrations below ambient air quality standards were estimated.

RESULTS

We estimated 5.2% of total YLL due to PM_2.5, of which, 33.5%, 52.8% and 94.5% occurred in concentrations not exceeding the criterion of WHO, the USA, and China, corresponding to 0.3, 0.4 and 0.7 years loss in life expectancy, respectively. There was 6.9% (annual 34434.4 YLL) of total YLL due to PM₁₀, of which, 50.7%, 50.7%, 99.5% and 99.5% occurred in concentrations below the criterion of WHO, Europe, the USA, and China, which corresponded to 0.5, 0.5, 1 and 1 year loss in life expectancy, respectively. Assuming that PM_2.5 and PM₁₀ concentrations had met stricter standards, more gains in life expectancy could be expected in women than in men, in people aged up to 64 years than those of 65 years or older, and in those with respiratory disease than those with cardiovascular disease.

CONCLUSIONS

Exposure to lower-than-standard particulate matters air pollution could shorten life expectancy and incur massive mortality burden in Hong Kong.

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.

Associations between PM2.5 exposure duration and physical activity intensity on the health of hypertension in urban residents of Beijing

Hypertension is reported to be associated with air pollution and physical activity (PA), and they have different or even conflicting effects on blood pressure (BP). The study evaluated the combined effects of PM2.5 exposure duration and physical activity intensity on systolic blood pressure (SBP) and diastolic blood pressure (DBP) of hypertension. A total of 2613 patients (≥18-year-olds) at baseline who attended surveys from the China Health and Nutrition Survey (2011-2015) in Beijing were selected, as well as the PM2.5 data collected in the same period. The mixed linear effects model and multivariate analysis of variance (MANOVA) were used to explore the multiple effects of PM2.5 exposure duration and PA intensity on SBP and DBP, respectively. The correlation results indicated PM2.5 exposure duration (>15 days) occurred more significant correlations with DBP and longer PM2.5 exposures duration (>60 day) with SBP. The mixed linear effects model showed the important random terms of gender, PA levels, and BMI classification for both SBP and DBP. It also indicated the significant fixed effect from age for both SBP and DBP, and the significant fixed effects from PM2.5 and weight, as well as the interaction in DBP. The random effects of PA levels put effects on different weight people for SBP and on different age people for DBP, while the person of SBP exposed to PM2.5 environments may tend to be affected by BMI classification. The model's main effects showed PA and the interaction with gender could put significant effects on BP. The gender effects and the PA level effects were also improved by the MANOVA results. We concluded that the more PM2.5 exposure duration may lead to more significant correlation with higher BP values. The PA levels could lead to the different effects on the health showing the variations in age, gender, and BMI classification. For SBP of people who are exposed to PM2.5 environments, it may tend to be affected by BMI classification, which also may influence the DBP through weight adjusting first and then cause hypertension. The gender difference of BP may be affected by PA showing the higher PA level and the more gender difference.