Is ambient air pollution associated with sarcopenia? Results from a nation-wide cross-sectional study

Independent and combined effects of volatile organic compounds on sarcopenia: Insights into environmental pollutants and muscle health

This study investigates the associations between volatile organic compound (VOC) exposure and sarcopenia, focusing on independent and combined effects and exploring potential biological mechanisms. Utilizing data from the National Health and Nutrition Examination Survey, we applied logistic regression to examine associations between individual VOCs and sarcopenia, while restricted cubic splines (RCS) assessed dose-response relationships. Weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) evaluated mixed exposure effects. Mediation analyses explored the roles of potential mediators, alongside bioinformatic analyses to investigate the underlying mechanisms. Multivariable logistic regression identified significant associations between specific VOCs and sarcopenia, particularly for DHBMA (OR=2.71, 95 % CI: 1.62-4.55). RCS confirmed both linear and nonlinear associations of specific VOCs. WQS analysis corroborated a synergistic effect of mixed VOC exposures and increased sarcopenia risk (OR=1.64, 95 % CI: 1.14-2.36), and BKMR analysis further confirmed this positive relationship. Mediation analysis revealed that inflammation, oxidative stress, and renal function partially mediated these associations (mediated proportions: 4.67-11.00 %). Bioinformatic analyses highlighted apoptosis-related targets and pathways as key mechanisms underlying the observed associations. This study provides comprehensive evidence linking VOC exposure to sarcopenia, emphasizing the importance of reducing VOC exposure to prevent sarcopenia and associated health risks.

A systematic review and meta-analysis of air pollution and increased risk of frailty

BACKGROUND

Environmental air pollution is increasingly recognised as a potential contributor to frailty. This systematic review and meta-analysis aimed to synthesise existing evidence on the associations between environmental air pollution and frailty in middle-aged and older adults, providing insights into the impact of air pollution on public health.

METHODS

The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement 2020. Four electronic databases were searched without restrictions on language, publication status, or year of publication.

RESULTS

Of the 145 publications identified through the systematic search, 18 were included. Meta-analyses indicated a 19% increased risk of frailty due to air pollution (fine particulate matter ≤2.5 microns) [n = 9 studies; pooled odds ratio (OR) 1.19; 95% confidence interval (CI) 1.10-1.27], a 28% increase with exposure to household solid fuels (n = 4 studies; OR 1.28; 95% CI 1.16-1.40) and a 59% increase due to exposure to secondhand smoke (n = 3 studies; OR 1.59; 95% CI 0.46-2.72). Except for the meta-analysis on air pollution, no heterogeneity or risk of publication bias was observed amongst the included studies. The Joanna Briggs Institute checklist confirmed high methodological quality across all included studies.

CONCLUSIONS

Environmental exposures, including air pollution, the use of unclean household fuels and exposure to secondhand smoke, significantly increase the risk of frailty. These findings underscore the urgent need to raise awareness and establish effective public health strategies to reduce these environmental risks and associated frailty, particularly in light of population ageing.

Association of residential green space with risk of sarcopenia and the role of air pollution: Evidence from UK Biobank

This study aims to explore the association between residential green space exposure and sarcopenia, and the role of air pollutants in the association. This study utilized data from the UK Biobank. Residential green space and natural environment were assessed by the percentage of land covered by greenness within 300 m and 1000 m buffers. Logistic regression models were used to explore the associations of green space and natural environment with possible sarcopenia and sarcopenia. We explored the mediating role of air pollution mixtures in the above associations. Interactions between green space and air pollution were assessed on the multiplicative and the additive scales. A total of 430790 participants were included in this study, and 23637 (5.5%) possible sarcopenia and 769 (0.2%) sarcopenia cases were identified. Each 10% increment of green space and natural environment coverage was associated with lower risks of possible sarcopenia (odds ratio (OR): 0.968, 95% confidence interval (CI): 0.961, 0.976 in green space; OR: 0.968, 95%CI: 0.962, 0.975 in natural environment) and sarcopenia (OR: 0.958, 95%CI: 0.920, 0.999 in green space; OR: 0.961, 95%CI: 0.926, 0.998 in natural environment). Population-attributable fraction analyses revealed that lower green space and natural environment levels could attribute to 8.8% and 8.5% of possible sarcopenia, 17.0% and 15.4% of sarcopenia. The associations of green space and natural environment with possible sarcopenia status could be partially explained by reducing air pollution. We also identified a significant multiplicative interaction between air pollution mixtures and green space on possible sarcopenia. In summary, higher green space and natural environment levels were associated with lower risks of possible sarcopenia and sarcopenia. Both modification and mediation roles of air pollution were found in the association between green space and possible sarcopenia. Therefore, expanding green space and reducing air pollution are crucial strategies for mitigating the risk of sarcopenia and promoting healthy aging.

Association between indoor ventilation frequency and low muscle mass among older adults in China: a national cross-sectional research

Previous studies have established associations between indoor air pollution and loss of muscle mass. While indoor ventilation improves indoor air quality, its association with low muscle mass (LMM) remains unexplored. We investigated the association between indoor ventilation frequency (IVF) and LMM in older Chinese adults. Utilizing data from the China Longitudinal Healthy Longevity Survey (CLHLS), IVF was assessed via self-reported weekly window-opening frequency in each season of the past year. LMM was defined using appendicular skeletal muscle mass (ASM) prediction equations. Binary logistic regression models were employed to evaluate the association between IVF and LMM, with subgroup and sensitivity analyses conducted. After adjusting for covariates, participants with intermediate IVF (OR: 0.805; 95% CI: 0.669-0.969) and high IVF (OR: 0.818; 95% CI: 0.684-0.979) were 19.5% and 18.2% less likely to develop LMM, compared with participants with low IVF. The probability of LMM in the spring was 25.3% (OR: 0.747; 95% CI: 0.581-0.961) and 23.3% (OR: 0.767; 95% CI: 0.597-0.985) lower in the middle and high IVF elderly populations, respectively, whereas the probability of LMM in the spring was 36.5% (OR: 0.625; 95% CI: 0.474-0.824) and 34.1% (OR: 0.659; 95% CI: 0.501-0.868). The association between IVF and LMM was statistically significant (p < 0.05) in gender, age, residence, living arrangement, marital status, economic situation, work, smoking, drinking, exercise, cooking ventilation, life satisfaction, self-rated health, hypertension, diabetes, heart disease, dementia, and NO2. Interaction analyses showed a significant interaction effect between the drinking subgroup and IVF (P for interaction < 0.05). Higher IVF is significantly associated with a lower risk of LMM. Optimizing ventilation practices may mitigate LMM burden in older adults, informing personalized health strategies.

Association of sarcopenia, ambient air pollution and cognitive function in a community-dwelling middle-aged and elderly Korean population: a community-based cohort study

OBJECTIVES

To investigate the association of sarcopenia, exposure to medium-term to long-term ambient particulate matter 2.5 µm and 10 µm (PM2.5 and PM10) pollution and cognitive function in a community-dwelling cohort of middle-aged and older adults in South Korea.

DESIGN

A community-based prospective cohort study.

SETTING

In the Korean Genome and Epidemiology Study (KoGES).

PARTICIPANTS

The participants were drawn from the seventh follow-up visit conducted between 2015 and 2016 in the KoGES community-based Ansung cohort who had participated in an ageing substudy.

OUTCOME MEASURES

Cognitive function was evaluated by the Korean version of the Mini-Mental State Examination (K-MMSE) and decreased cognitive function was defined as a K-MMSE score of 23 or less.

RESULTS

Of the 2274 participants (mean age 70.1 years, 58.3% women and mean annual PM2.5 and PM10 levels of 30.7 and 52.2 μg/m3, respectively), 8.7% (n=197) were sarcopenic, 35.8% (n=814) were possible sarcopenic and 55.5% (n=1263) were non-sarcopenic. The predictors of sarcopenia included body mass index, cognitive function, age, marital status, hypertension and physical activity. Exposure to PM2.5 and PM10 for an average duration of 1 month to 3 years was not selected as a predictor of sarcopenia. Participants with sarcopenia were associated with lower cognitive scores (β=-1.51, p<0.0001) and decreased cognitive function compared with those without sarcopenia (OR 2.34, 95% CI 1.56 to 3.52). Exposure to medium-term and long-term PM2.5 or PM10 was not associated with sarcopenia. The effect modification of PM exposure on the association between sarcopenia and cognitive function was generally not detected.

CONCLUSIONS

In this community-based observational cohort study of KoGES participants aged 50 years and older, sarcopenia was associated with decreased cognitive function. However, medium-term to long-term exposure to PM2.5 or PM10 was not associated with sarcopenia and did not modify the relationship between sarcopenia and cognitive function.

Indoor air pollution by solid fuel usages for cooking is longitudinally associated with possible sarcopenia in middle-aged Chinese population

Objectives

The Asia Working Group of Sarcopenia (AWGS) 2019 consensus proposed a new concept named "possible sarcopenia". The present study was to estimate the association between indoor air pollution by solid fuel usages for cooking and possible sarcopenia among middle-aged and older Chinese population.

Methods

A longitudinal cohort analysis was carried out using nationally representative data from the China Health and Retirement Longitudinal Study (CHARLS). A total of 17,708 participants were recruited and followed up in the CHARLS. Cox proportional hazards models were used to estimate the effects of cooking fuel usages on the new onset of possible sarcopenia. Stratified analyses were performed according to gender and age, and sensitivity analyses were performed using the complete dataset.

Results

A total of 4,653 participants were included in the final cohort analysis. During the follow-up of 4 years (2011-2015), a total of 1,532 (32.92%) participants developed new-onset possible sarcopenia. Compared with clean fuel usages for cooking, solid fuel usages were associated with a higher risk of possible sarcopenia (HR = 1.37, 95% CI = 1.23-1.52, p-value < 0.001). After adjusting for potential confounders, there was a trend for association between solid fuel usages and an increased risk of possible sarcopenia. Stratified analyses by gender and age demonstrated a stronger association of the solid fuel usages with possible sarcopenia in the middle-aged female participants (Model 1: HR = 1.83, 95% CI = 1.24-2.69, p-value = 0.002; Model 2: HR = 1.65, 95% CI = 1.10-2.47, p-value = 0.016). Sensitivity analyses indicated that the results were robust.

Conclusion

Indoor air pollution from solid fuel usages for cooking was a modifiable risk factor for sarcopenia, especially in middle-aged female population. These findings provide a new prevention strategy to reduce the growing burden of sarcopenia, especially for middle-aged female individuals using solid fuels for cooking.

Association between probable sarcopenia and dementia risk: a prospective cohort study with mediation analysis

The role of alcohol consumption as a mediator in the risk between sarcopenia and dementia remains inadequately studied. There is currently limited research on whether the association between sarcopenia and the risk of Alzheimer's disease (AD) is influenced by genetic susceptibility. Our study incorporated a total of 483,637 baseline non-dementia participants, who were classified into groups of individuals with no sarcopenia and those with probable sarcopenia based on the definition. We employed Cox proportional hazards models to evaluate the association between probable sarcopenia and the risk of all cause dementia (ACD), AD, and vascular dementia (VD). We conducted mediation analysis to explore the role of alcohol consumption in the association between probable sarcopenia and the risk of ACD, AD, and VD. During the median follow-up period of 13.6 years, we documented 9000 new cases of ACD (including 4061 AD and 2025 VD). Fully adjusted multivariate model revealed a significant correlation between probable sarcopenia and elevated risk for ACD (HR = 1.54, 95% CI: 1.46-1.62, p < 0.001), AD (HR = 1.32, 95% CI: 1.21-1.43, p < 0.001), and VD (HR = 1.69, 95% CI: 1.52-1.89, p < 0.001). Mediation analysis elucidates that alcohol consumption explained 12.8%, 15.2%, and 11.1% of the associations of probable sarcopenia with the risk of ACD, AD, and VD, respectively. An interactive relationship prevails between probable sarcopenia and genetic factors (p for interaction <0.001), and regardless of the degree of genetic risk, probable sarcopenia correlates with an elevated AD risk. Our study reveals a significant association between probable sarcopenia and an increased risk of dementia, with alcohol consumption playing a mediating role in this association. There is an interaction between probable sarcopenia and genetic susceptibility related to the risk of AD.

Health effect of multiple air pollutant mixture on sarcopenia among middle-aged and older adults in China

BACKGROUND

As the global aging process accelerates, the health challenges posed by sarcopenia among middle-aged and older adults are becoming increasingly prominent. However, the available evidence on the adverse effects of air pollution on sarcopenia is limited, particularly in the Western Pacific region. This study aimed to explore relationships of multiple air pollutants with sarcopenia and related biomarkers using the nationally representative database.

METHODS

Totally, 6585 participants aged over 45 years were enrolled from the China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 3443 of them were followed up until 2015. Air pollutants were estimated from high-resolution satellite-based spatial-temporal models. In the cross-sectional analysis, we used generalized linear regression, unconditional logistic regression analytical and restricted cubic spline (RCS) methods to assess the single-exposure and non-linear effects of multiple air pollutants on sarcopenia and related surrogate biomarkers (serum creatinine and cystatin C). Several popular mixture analysis techniques such as Bayesian kernel machine regression (BKMR), weighted quantile sum (WQS) regression, and quantile-based g-computation (Qgcomp) were further used to examinate the combined effects of multiple air pollutants. Logistic regression was used to further analyze the longitudinal association between air pollution and sarcopenia.

RESULTS

Each interquartile range increase in PM2.5, PM10 and NO2 was significantly associated with an increased risk of sarcopenia, with adjusted odds ratios (aORs) of 1.09 [95 % confidence interval (CI): 1.01, 1.20], 1.24 (95 % CI: 1.14, 1.35) and 1.18 (95 % CI: 1.08, 1.28), respectively. Our findings also showed that five air pollutants were significantly associated with the sarcopenia index. In addition, employing a mixture analysis approach, we confirmed significant combined effects of air pollution mixtures on sarcopenia risk and associated biomarkers, with PM10 and PM2.5 identified as major contributors to the combined effect. The results of the exposure-response (E-R) relationships, subgroup analysis, longitudinal analysis and sensitivity analysis all showed the unfavorable impact of air pollution on sarcopenia risk and related vulnerable populations.

CONCLUSIONS

Single-exposure and co-exposure to multiple air pollutants were positively associated with sarcopenia among middle-aged and older adults in China. Our study provided new evidence that air pollution mixture was significantly associated with sarcopenia related biomarkers.

Sarcopenia and mild kidney dysfunction and risk of all-cause and cause-specific mortality in older adults

BACKGROUND

Sarcopenia has been identified as a risk factor for increased mortality in individuals with CKD. However, when considering individuals with mild kidney dysfunction prior to CKD, the impact of sarcopenia on adverse outcomes, particularly mortality, remains uncertain.

METHODS

This study included 323 801 participants from the UK Biobank. Mild kidney dysfunction was defined as estimated glomerular filtration rate between 60 and 89.9 mL/min/1.73 m2, and sarcopenia was defined according to the criteria of the 2019 European Working Group of Sarcopenia in Older People. Cox proportional hazard models with inverse probability weighting and competing risk models were used for analysis.

RESULTS

During a median follow-up of 11.8 years, 20 146 participants died from all causes. Compared with participants with normal kidney function and without sarcopenia, those with mild kidney dysfunction or sarcopenia had significantly increased risks of all-cause mortality [hazard ratio (HR) 1.16, 95% confidence interval (CI) 1.12-1.19; HR 1.29, 95% CI 1.20-1.37]; those with both mild kidney dysfunction and sarcopenia had an even higher risk of all-cause mortality (HR 1.61, 95% CI 1.52-1.71), with a significant overall additive interaction (relative risk due to interaction 0.17, 95% CI 0.05-0.29). Further subgroup analyses revealed that the associations of probable sarcopenia with all-cause and cause-specific mortality (non-accidental cause, non-communicable diseases and cancer) were stronger among participants with mild kidney dysfunction than those with normal kidney function.

CONCLUSIONS

The study indicates that sarcopenia and mild kidney dysfunction synergistically increase the risk of all-cause and cause-specific mortality. Early recognition and improvement of mild kidney function or sarcopenia in older people may reduce mortality risk but would require more prospective confirmation.

Ambient air pollution exposure and the risk of probable sarcopenia: A prospective cohort study

BACKGROUND

Sarcopenia is characterized by decreased muscle mass and strength, posing threat to quality of life. Air pollutants are increasingly recognized as risk factors for diseases, while the relationship between the two remains to be elucidated. This study investigated whether exposure to ambient air pollution contributes to the development of sarcopenia.

METHODS

We employed the data from the UK Biobank with 303,031 eligible participants. Concentrations of PM2·5, NO2, and NOx were estimated. Cox proportional hazard regression models were applied to investigate the associations between pollutants and sarcopenia.

RESULTS

30,766 probable sarcopenia cases was identified during the follow-up. We observed that exposure to PM2.5 (HR, 1.232; 95% CI, 1.053-1.440), NO2 (HR, 1.055; 95% CI, 1.032-1.078) and NOx (HR, 1.016; 95% CI, 1.007-1.026) were all significantly associated with increased risk for probable sarcopenia for each 10 μg/m3 increase in pollutant concentration. In comparison with individuals in the lowest quartiles of exposure, those in the upper quartiles had significantly increased risk of probable sarcopenia. Sarcopenia-related factors, e.g., reduced lean muscle mass, diminished walking pace, and elevated muscle fat infiltration ratio, also exhibited positive associations with exposure to ambient air pollution. On the contrary, high level physical activity significantly mitigated the influence of air pollutants on the development of probable sarcopenia.

CONCLUSIONS

Air pollution exposure elevated the risk of developing sarcopenia and related manifestations in a dose-dependent manner, while physical activity maintained protective under this circumstance. Efforts should be made to control air pollution and emphasize the importance of physical activity for skeletal muscle health under this circumstance.

Household use of solid fuel and sarcopenia among middle-aged and older adults: The China Health and Retirement Longitudinal Study

OBJECTIVE

Few studies have examined the effects of air pollution on the risk of sarcopenia, especially pollution in indoor settings. We explored the cross-sectional and longitudinal associations of household use of solid fuel for cooking and heating, separately and simultaneously, with risk of sarcopenia.

METHODS

Cross-sectional and follow-up data from the China Health and Retirement Longitudinal Study were used. Multivariable-adjusted generalized linear models and Cox proportional hazards regression models were performed to estimate the odds ratio and hazard ratio for sarcopenia, respectively.

RESULTS

11,494 (median age: 57.0 years; 47.4 % males) and 7483 (median age: 57.0 years; 46.9 % males) participants were included in the cross-sectional and longitudinal study, respectively. After fully adjusting for covariates, including outdoor concentration of particulate matter (PM2.5), both the use of solid fuels for cooking and use for heating were positively associated with incident sarcopenia in the longitudinal analyses, with hazard ratios (95 % confidence interval) of 1.56 (1.28-1.89) and 1.26 (1.04-1.52), respectively. Moreover, significant multiplicative and/or additive interactions were observed between age, smoking and cooking with solid fuel and risk of sarcopenia (all P for interaction <0.05). Similar results were found in the cross-sectional analyses.

CONCLUSIONS

Household use of solid fuel was significantly associated with a higher risk of sarcopenia, while ageing and smoking had synergetic effects with burning solid fuels on the risk of sarcopenia. Our results highlight the importance of taking multi-pronged measures with respect to both air pollution and healthy lifestyle to prevent sarcopenia and promote healthy ageing.

Long-term exposure to ambient air pollution with sarcopenia among middle-aged and older adults in China

BACKGROUND

Few studies have examined the role of outdoor air pollution exposure in sarcopenia in Asia. We aimed to investigate the association of outdoor air pollutants exposure with sarcopenia among Chinese adults.

METHODS

This nationally population-representative study used data from the China Health and Retirement Longitudinal Study (CHARLS) in 2015, 11,700 participants at least 45 years old from 125 Chinese cities were included. Sarcopenia status was identified according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria. Ambient annual average air pollutants including fine particulate matter (PM2.5), inhalable particles (PM10), coarse particulate matter (PMcoarse), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) were estimated by satellite models and ground-based measurements. Multinomial logistic regression models were performed to examine the associations of air pollutants exposure with different status of sarcopenia (including possible sarcopenia and sarcopenia). Stratified analyses were utilized to assess the effect modifiers.

RESULTS

Among the 11,700 participants (52.6% women), the average age was 61.0 years. Each 10 μg/m3 increment of annual PMcoarse was associated with a higher risk of possible sarcopenia (odds ratio (OR) = 1.08, 95% confidence interval (CI) 1.04-1.11). Stratified analyses showed a positive risk of possible sarcopenia in women after exposure to PM10, PMcoarse, and NO2. Ambient NO2 exposure was positively associated with sarcopenia (OR = 1.13, 95% CI 1.04-1.22) in those aged 65 years and older. However, we have not observed differences by sex, age, residence, smoking, and drinking. Robustness results were found for PMcoarse in the sensitivity analyses.

CONCLUSION

This nationwide study suggested that long-term exposure to outdoor air pollution, especially for PMcoarse, was associated with the risk of sarcopenia among Chinese adults. Our findings provide epidemiological implications for protecting healthy ageing by improving air quality.

Unclean Cooking Fuel Use and Slow Gait Speed Among Older Adults From 6 Countries

BACKGROUND

Outdoor air pollution has been reported to be associated with frailty (including slow gait speed) in older adults. However, to date, no literature exists on the association between indoor air pollution (eg, unclean cooking fuel use) and gait speed. Therefore, we aimed to examine the cross-sectional association between unclean cooking fuel use and gait speed in a sample of older adults from 6 low- and middle-income countries (China, Ghana, India, Mexico, Russia, and South Africa).

METHODS

Cross-sectional, nationally representative data from the World Health Organization Study on global AGEing and adult health were analyzed. Unclean cooking fuel use referred to the use of kerosene/paraffin, coal/charcoal, wood, agriculture/crop, animal dung, and shrubs/grass based on self-report. Slow gait speed referred to the slowest quintile based on height, age, and sex-stratified values. Multivariable logistic regression and meta-analysis were done to assess associations.

RESULTS

Data on 14 585 individuals aged ≥65 years were analyzed (mean [standard deviation] age 72.6 [11.4] years; 45.0% males). Unclean cooking fuel use (vs clean cooking fuel use) was significantly associated with higher odds for slow gait speed (odds ratio = 1.45; 95% confidence interval: 1.14-1.85) based on a meta-analysis using country-wise estimates. The level of between-country heterogeneity was very low (I2 = 0%).

CONCLUSIONS

Unclean cooking fuel use was associated with slower gait speed among older adults. Future studies of longitudinal design are warranted to provide insight into the underlying mechanisms and possible causality.

Association of indoor solid fuel use and long-term exposure to ambient PM2.5 with sarcopenia in China: A nationwide cohort study

BACKGROUND

Little is known about the association between air pollution exposure and sarcopenia in Asia. We aimed to investigate the associations of indoor solid fuel use and long-term exposure to ambient fine particulate matter (PM2.5) with sarcopenia in China.

METHODS

Using a nationally population-representative study, 12,723 participants aged at least 45 years across 125 cities from the China Health and Retirement Longitudinal Study were enrolled in 2011, and further 3110 participants were followed up until 2013. Sarcopenia status was classified according to the Asian Working Group for Sarcopenia 2019 criteria. Household fuel types used for heating and cooking were assessed using a standard questionnaire. Ambient annual PM2.5 was estimated using satellite-based spatiotemporal models. Multinomial logistic regression as well as the multiplicative interaction and additive interaction analysis were used to explore the associations of indoor solid fuel and ambient PM2.5 with different status of sarcopenia.

RESULTS

Of the 12,723 participants, 6071 (47.7%) were men. In the cross-sectional analyses, compared with clean fuel, using solid fuel for heating and cooking, separately or simultaneously, was significantly associated with a higher risk of both possible sarcopenia and sarcopenia. Each 10 μg/m3 increment of PM2.5 was positively related to possible sarcopenia (adjusted odds ratio, [aOR] 1.04, 1.02-1.07) and sarcopenia (1.06, 1.01-1.12). We found a significant interaction between solid fuel use for heating and ambient PM2.5 exposure with possible sarcopenia. During a two-year follow-up, solid fuel use was associated with incident possible sarcopenia (aOR 1.59, 1.17-2.15). These associations did not differ by sex and age, while participants living in a house with poor cleanliness might have a higher risk of sarcopenia.

CONCLUSIONS

Indoor solid fuel use and long-term exposure to ambient PM2.5 were associated with a higher risk of sarcopenia among Chinese adults. These findings provide implications for promoting healthy aging by reducing air pollution.

Long-term exposure to air pollution and risk of Sarcopenia in adult residents of Taiwan: a nationwide retrospective cohort study

BACKGROUND

Sarcopenia is an age-related, multifactorial syndrome. Previous studies have shown that air pollutants are associated with inflammation and oxidative stress. However, the association between long-term exposure to air pollution and sarcopenia is not completely understood.

METHODS

The Taiwan National Health Research Database (NHIRD) contains medical records of almost all Taiwanese residents. Daily air pollution data collected by the Taiwan Environmental Protection Agency was used to analyze concentrations of sulfur oxide (SO2), carbon monoxide (CO), nitrogen monoxide (NO), nitrogen dioxide (NO2), and particulate matter (PM2.5, PM10). The databases were merged according to the insurants' living area and the location of the air quality monitoring station. We categorized the pollutants into quartiles (Q1, Q2, Q3, and Q4).

RESULTS

Our study population consisted of 286,044 patients, among whom 54.9% were female and 45.1% were male. Compared to Q1 levels of pollutants, Q4 levels of SO2 (adjusted hazard ratio [aHR] = 8.43; 95% confidence interval [CI] = 7.84, 9.07); CO (aHR = 3.03; 95%CI = 2.83, 3.25); NO (aHR = 3.47; 95%CI = 3.23, 3.73); NO2 (aHR = 3.72; 95%CI = 3.48, 3.98); PM2.5 (aHR = 21.9; 95% CI = 19.7, 24.5) and PM10 (aHR = 15.6; 95%CI = 14.1, 17.4) increased risk of sarcopenia.

CONCLUSIONS

Our findings indicated a significantly increased risk of sarcopenia in both male and female residents exposed to high levels of air pollutants.

The longitudinal association between indoor air pollution and sarcopenia in China: the mediating role of depression

Several studies showed that indoor air pollution may pose significant risks to public health, causing illnesses such as pulmonary and cardiovascular disorders. It is known very little of the association between air pollution and sarcopenia in older Chinese adults. We conducted a cohort study to examine the detrimental health effects of indoor solid fuel use for heating and cooking on sarcopenia and further explore the mediating role of depression and C-reaction protein (CRP). The sample of the study consists of 2088 participants from the CHARLS 2011-2015. Sarcopenia status was assessed according to the AWGS 2019 criteria. Participants were asked specific questions about the source of their primary heating and cooking fuels, which served as the basis for defining solid fuel use. Multivariate logistic regressions were constructed to explore the relationship between indoor solid fuel use and sarcopenia or possible sarcopenia. Serial mediation analyses were applied to explore the potential mediating role of depression and CRP in the relationship. Among all participants, 224 and 61 had possible sarcopenia or sarcopenia. Compared to individuals who used clean fuel for heating and cooking, participants who utilized indoor solid fuel for heating exhibited a higher risk of possible sarcopenia or sarcopenia, with OR (and 95% CI) of 1.48 (1.04, 2.11) and 8.42 (2.01, 35.32). The risk of possible sarcopenia demonstrates a gradual increase in correlation with the duration of solid fuel usage for heating (P for trend <0.01). Approximately 16.27% of the relationship between indoor solid fuel use and possible sarcopenia is mediated by depression. Our stratified analysis indicates that participants residing in a city/town are associated with higher odds of possible sarcopenia. Additionally, our sensitivity analysis demonstrates that our estimates are generally robust and consistent. Indoor heating using solid fuels is associated with a higher risk of sarcopenia, while prolonged exposure to household air pollution is found to be positively correlated with this increased risk. Furthermore, depression plays a mediating role in this relationship.

Association between Household Solid Fuel Use and Sarcopenia Risk among Middle-Aged and Older Adults in China: A Nationwide Population-Based Cohort Study

BACKGROUNDS

Household solid fuel have been associated with changes of handgrip strength, and exposure to ambient air pollution might be one risk factor of sarcopenia. However, the prospective association between household solid fuel use and sarcopenia remains limited.

METHODS

A total of 11,924 participants (5,723 men (48%) and 6,201 women (52%) with the average age was 59.17 ± 9.57 years) from the China Health and Retirement Longitudinal Study 2011 were included in cross-sectional analyses. 7,507 participants at baseline were included in longitudinal analyses and were followed up in 2015. Sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria.

RESULTS

In cross-sectional analyses, the participants who used solid fuel for cooking and heating had higher prevalence of sarcopenia than those who used clean fuel. During the follow-up, 302 (4.02%) participants experienced sarcopenia. In the longitudinal analysis, after multivariable adjustment of age, sex and other risk factors, individuals who used solid fuel for cooking had an elevated risk of new-onset sarcopenia, with corresponding odds ratio of 1.32 (95% confidence interval, 1.03-1.71). Consistently, individuals reported solid fuels use for heating were associated with 20% (odds ratio=1.20, 95% confidence interval: 1.01-1.56) increased risk of sarcopenia. In addition, a self-reported switch from clean to solid fuel for cooking appeared to have an increased sarcopenia risk (odds ratio=1.20, 95% confidence interval: 1.02-1.43).

CONCLUSION

Using household solid fuel for cooking and heating was associated with increased risk of sarcopenia prevalence and incidence.