Association between biomass fuel use and risk of hypertension among Chinese older people: A cohort study

Denture use and a slower rate of cognitive decline among older adults with partial tooth loss in China: A 10-year prospective cohort study

Objective

Denture use has been shown to improve nutritional intake and diet quality in people with tooth loss. Despite evidence linking tooth loss and dementia, few studies have examined the association between denture use and cognitive decline. We investigated the relationship between denture use and cognitive decline among Chinese older adults with tooth loss.

Methods

We analyzed data from the Chinese Longitudinal Healthy Longevity Survey 2008-2018, including 27,708 community-dwelling dentate and edentulous (i.e., who have lost all natural teeth) older adults aged 65 and older. Cognitive function was assessed using the Mini-Mental State Examination from 2008 to 2018. Linear mixed-effect models were employed to assess the association of denture use with baseline cognitive function and rate of cognitive decline, adjusting for sociodemographic characteristics, health-related behavior, and health status. Subgroup analyses evaluated differences in associations among dentate participants with varying degrees of tooth loss (1-9, 10-19, 20-31).

Results

Compared to non-denture users, dentate participants who used dentures had better baseline cognitive function (β, 1.032; 95% CI, 0.813-1.251; p < 0.001) and a slower annual decline in cognitive function (β, 0.127; 95% CI, 0.047-0.206; p < 0.01). For edentulous participants, denture use was associated with higher baseline cognitive function (β, 3.063; 95% CI, 2.703-3.423; p < 0.001) but not with the rate of cognitive decline (β, 0.011; 95% CI, -0.082 to 0.105; p = 0.818). Results remained consistent across subgroups of dentate participants with various degrees of missing teeth.

Conclusions

Denture use may help protect against cognitive decline in older adults with partial tooth loss. This study highlights the potential importance of prosthodontic rehabilitation in preserving cognitive health. Further research is needed to establish a causal relationship between denture use and cognitive function.

Household fuel use and the regression from prehypertension to normotension among Chinese middle-aged and older adults: a cohort study

To examine the association of household fuel use with prehypertension regression among middle-aged and older people based on the China Health and Retirement Longitudinal Study (CHARLS), we included a total of 3501 participants with prehypertension at baseline, and they were followed up from 2011-2012 to 2015-2016 with information on blood pressure and household solid fuel use (heating and cooking fuels). Cox proportional hazards regression models were used to explore the hazard ratio (HR) and 95% confidence interval (CI) between fuel use and prehypertension regression. Additionally, we investigated the impact of switching fuels (2011-2013) on the regression to normotension during the 4-year follow-up. Linear regression was used to examine the effect of household fuel use on changes in blood pressure. Compared to solid fuel users, those who used clean fuel for heating at baseline had a positive effect on the regression of prehypertension (HR: 1.28, 95% CI: 1.08-1.53). Participants who used clean fuels for both heating and cooking had increased odds for the regression of prehypertension (HR: 1.32, 95% CI: 1.09-1.60). Compared to consistent solid fuel users, those who consistently used clean fuel for heating had a higher likelihood of transitioning from prehypertension to normotension (HR: 1.36, 95% CI: 1.06-1.73) and exhibited 2.45 mmHg lower systolic blood pressure. In conclusion, household clean fuel use for heating was positively associated with the regression of prehypertension to normotension. Furthermore, switching from solid fuel to clean fuel for heating could reduce the risk of prehypertension in Chinese middle-aged and older adults.

Examining the Impact of Natural Teeth Trajectory on Mortality Among CLHLS

BACKGROUND

To investigate the associations between trajectories of the number of natural teeth and all-cause mortality among Chinese middle-aged and older adults.

METHODS

Data for this study were sourced from the 2002, 2005, 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The number of natural teeth was assessed through self-reports. Population-based trajectory models were utilised to explore potential heterogeneity in longitudinal changes over 16 years and to examine the associations between baseline predictors and different trajectories among cohort members. Additionally, the Cox proportional hazards model was employed to assess the risk factors associated with these trajectories.

RESULTS

Three distinct trajectories in the number of natural teeth were identified: fewer teeth (33.34%), a moderate number of teeth (47.58%), and most teeth retained (19.08%). Several factors were found to influence changes in these trajectories: older age, male gender, poor self-reported health status, impaired vision, a higher number of chronic diseases, diminished cognitive function, and reduced frequency of social activities. Compared to the group with fewer teeth, those with moderate and most teeth demonstrated a better prognosis.

CONCLUSION

The number of natural teeth is associated with mortality, and retaining more natural teeth may play a significant role in promoting healthy aging.

The Association Between Solid Fuel Use and Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Hyperplasia in Sichuan, China: Cross-Sectional Study

Background

Benign prostatic hyperplasia (BPH) is a global age-related disease. It has been reported that over half of the Chinese male population aged 70 years or older are experiencing BPH. Solid fuel, which is the major source of household air pollution, has been reportedly associated with several adverse events, including sex hormone disorders. Due to the certain relationship between sex hormone levels and prostate disease, the relationship between solid fuel use and lower urinary tract symptoms (LUTSs) suggestive of BPH (LUTS/BPH) deserves further exploration.

Objective

This study mainly aimed to investigate the association between solid fuel use and LUTS/BPH.

Methods

The data used in this study were obtained from the West China Natural Population Cohort Study. Household energy sources were assessed using questionnaires. LUTS/BPH was evaluated based on participant self-reports. We performed propensity score matching (PSM) to reduce the influence of bias and unmeasured confounders. The odds ratio (OR) and 95% CI of LUTS/BPH for the solid fuel group compared with the clean fuel group were calculated. We also conducted stratified analyses based on BMI, metabolic syndrome, waist to hip ratio, drinking status, smoking status, and age.

Results

A total of 5463 participants were included in this study, including 399 solid fuel users and 5064 clean fuel users. After PSM, the solid fuel group included 354 participants, while the clean fuel group included 701 participants. Solid fuel use was positively correlated with LUTS/BPH before and after PSM (OR 1.68, 95% CI 1.31-2.15 and OR 1.81, 95% CI 1.35-2.44, respectively). In stratified analyses, the OR of the nonsmoking group was higher than that of the smoking group (OR 2.56, 95% CI 1.56-4.20 and OR 1.47, 95% CI 0.99-2.18, respectively). Similarly, the OR of the nondrinking group was higher than that of the drinking group (OR 2.70, 95% CI 1.46-4.99 and OR 1.48, 95% CI 1.01-2.17, respectively).

Conclusions

A positive correlation between solid fuel use and LUTS/BPH was observed. The results suggest that improving fuel structure for household cooking and other household needs can possibly help reduce the risk of LUTS/BPH.

Impact of Indoor Air Pollutants on the Cardiovascular Health Outcomes of Older Adults: Systematic Review

Indoor air pollution accounts for approximately 3.8 million inopportune deaths annually at global level. Due to spending more time indoors, children and older adults are especially susceptible to the health risks of indoor air pollution. This review seeks to summarise existing knowledge on the cardiovascular health effects of three common indoor air pollutants, namely carbon monoxide (CO), particulate matter (PM2.5 and PM10), and Nitrogen dioxide (NO2), focusing on older adults. We systematically reviewed the literature (PROSPERO CRD42024479220) on PubMed, Google Scholar, Scopus, Web of Science and Embase. The search yielded 20,914 records. Two independent reviewers screened the articles using titles, abstracts, and full-length articles written in English. Upon a detailed assessment of all the records, the review considered 38 full-length articles. Several studies reported mortality, myocardial infarction, stroke, increased hospitalisation and increased emergency room visits due to exposure to indoor air pollution. A few studies reported arrhythmias, hypertension and Ischaemic heart disease due to exposure to indoor air pollutants. The increased mortality, morbidity, hospitalization, and emergency rooms visits resulting from indoor air pollution associated CVDs makes indoor air pollution a health risk for older adults. There is, therefore, a need to synthesize information on studies relate d to how the selected indoor air pollutants affected the cardiovascular health of older adults.

Association between cMIND diet and hypertension among older adults in China: a nationwide survey

BACKGROUND

Existing research indicates that the Mediterranean diet has a positive impact on preventing and treating hypertension. However, its specific effect on hypertension among elderly Chinese individuals is unclear.

AIMS

The objective of this research was to explore the association between the Chinese version of the Mediterranean-DASH Intervention for Neurodegenerative Delay (cMIND) diet and hypertension among elderly Chinese individuals, aiming to offer novel strategies for alleviating the burden of hypertension in this demographic.

METHODS

In this study, we used cross-sectional data published in 2018 by the China Longitudinal Health and Longevity Survey (CLHLS) to develop a binary logistic regression model to investigate the correlation between cMIND diet and hypertension in a Chinese elderly population. Restricted cubic spline was used to test for linear associations, and further subgroup analyses were performed to test for interactions.

RESULTS

In total, 7,103 older adults were included in the study, with a prevalence of hypertension of 39.0%. When the cMIND diet score was used as a continuous variable, a significant protective effect against hypertension was present (OR = 0.955, 95% CI:0.923-0.988, p = 0.008); when used as a categorical variable, this protective effect was still present at higher levels (compared to lower levels) of the cMIND diet (OR = 0.869, 95% CI: 0.760-0.995, p = 0.042).

DISCUSSION

Although the Mediterranean diet has great potential to reduce the chance of hypertension, it should also consider the effect on the Chinese population. The results of this study provide new ways to reduce the disease burden of hypertension in Chinese older adults and improve quality of life in later life.

CONCLUSION

The cMIND diet can considerably reduce the risk of hypertension among older adults in China.

Association of increased participation in social activity in later life with risk of all-cause mortality and heart diseases in older people: results from the Chinese Longitudinal Healthy Longevity Survey (CLHLS)

Background

Previous studies have shown social activity is associated with reduced risk of health outcomes. However, among older people (≥65 years) who were socially inactive at baseline, limited study explored whether increased participation in social activity in later life was associated with reduced risk of health outcomes; therefore, using the data from the Chinese Longitudinal Healthy Longevity Survey, the study was performed.

Methods

The study outcomes were 10-year all-cause mortality (sample number = 9,984) and 10-year heart diseases (sample number = 7,496). The exposure was the change of social activity frequency. Cox regression analysis was used for data analysis.

Results

During the follow-up, there were 6,407 all-cause mortalities and 1,035 heart diseases, respectively. Kaplan-Meier analysis demonstrated that cumulative incidences of all-cause mortality were significantly lower in participants with changes into more frequent social activity (log-rank p < 0.001), while no significant difference was observed for heart diseases (log-rank p = 0.330). Compared with the subgroup who never participated in social activity at baseline, adjusted HRs of all-cause mortality were 0.79 (95% CI: 0.70-0.90, p < 0.001), 0.78 (95% CI: 0.63-0.96, p = 0.019), 0.74 (0.59-0.92, p = 0.006), and 0.70 (95% CI: 0.56-0.88, p = 0.002) for the subgroup of switching to sometimes, the subgroup of switching to once a month, the subgroup of switching to once a week, and the subgroup of switching to everyday, respectively. The corresponding HRs of heart diseases were 0.83 (95% CI: 0.65-1.08, p = 0.170), 0.82 (95% CI: 0.51-1.31, p = 0.412), 0.91 (0.58-1.42, p = 0.675) and 0.75 (95% CI: 0.47-1.20, p = 0.227), respectively. Stratified and sensitivity analyses revealed similar results.

Conclusion

Among older people who never participated in social activity, increased participation in social activity in later life was associated with reduced risk of all-cause mortality, but was not associated with reduced risk of heart diseases.

Influence of type of cooking fuel on risk of hypertension among reproductive-age women in sub-Saharan Africa: insights from nationally representative cross-sectional surveys

BACKGROUND

Nearly one-third of the world's population (2.4 billion people) rely on unclean cooking fuel sources. The study assessed the association of the type of cooking fuel and hypertension risk in sub-Saharan Africa (SSA).

METHODS

The study analysed pooled data from 97 942 individuals in the Demographic and Health Survey (DHS) between 2014 and 2021 in 10 SSA countries. Univariate, bivariate and multivariate analyses were performed, including basic descriptive statistics and binary logistic regression. The independent variable of interest was the type of cooking fuel, while hypertension served as the outcome variable.

RESULTS

Women using unclean cooking fuel were 1.21 times more likely to be hypertensive compared with those using clean cooking fuel (adjusted odds ratio [aOR] 1.21 [95% confidence interval {CI} 1.11 to 1.31]). Older age (aOR 5.78 [95% CI 5.04 to 6.62]), higher education (aOR 1.14 [95% CI 1.05 to 1.23]), being married (aOR 1.64 [95% CI 1.49 to 1.80]), working in sales and services occupations (aOR 1.34 [95% CI 1.24 to 1.44]), frequent health facility visits (aOR 1.59 [95% CI 1.51 to 1.68]), higher wealth index and exposure to media were significantly associated with hypertension risk.

CONCLUSIONS

Efforts to reduce reliance on unclean cooking fuel at both the household and population levels need to be intensified in SSA countries. Promoting the use of clean cooking technologies and fuels and implementing supportive policies for transitioning from unclean cooking fuels are crucial. Targeted interventions to reduce hypertension risk in SSA should focus on women using unclean cooking fuel, older women, individuals from wealthier households and those with higher education levels.

Housing conditions, cooking fuels, and health-related quality of life among rural middle-aged and elderly in northwest China: A ten-year balanced panel study

To investigate the impacts of improving housing conditions and transitioning to clean cooking fuels on health-related quality of life (HRQOL) among middle-aged and elderly populations in rural China.

METHODS

Using a 10-year longitudinal follow-up study, we examined changes in housing conditions, cooking fuel use, and HRQOL among 690 Chinese adults aged 45 above in rural areas. HRQOL was assessed using the European Quality of Life-5 Dimensions 3 Levels (EQ-5D-3L) questionnaire. Generalized estimating equations were utilized to analyze correlations between variables.

RESULTS

Using four-period balanced panel data of 10 years, there were significant differences in the self-reporting of mobility, self-care, usual activities, pain / discomfort and anxiety / depression in rural middle-aged and elderly people (p < 0.05). In terms of the EQ-5D index score and EQ-VAS score, showed a decreasing trend (p < 0.05). The housing area, housing material type, utilization of sanitary toilets, separation of housing and kitchen were separated and non-solid fuels used as cooking fuel were significantly associated with high HRQOL (p < 0.05).

CONCLUSIONS

This study found that good housing conditions and the use of non-solid cooking fuel had positive effects on health-related quality of life of middle-aged and elderly people in rural areas of northwest China.

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.

Traffic-related air pollution, adherence to healthy lifestyles, and risk of cognitive impairment: A nationwide population-based study

BACKGROUND

Traffic-related air pollution (TRAP) is a risk factor for cognitive function, whereas healthy lifestyles are associated with better cognition. We aimed to examine their joint effects on cognition among the Chinese elderly.

METHODS

The data from the Chinese Longitudinal Healthy Longevity Survey was used. Participants' cognitive performance was assessed by the Chinese version of the mini-mental state examination. Residential proximity to major roadways was obtained through self-report and categorized into five categories: > 300 m, 201-300 m, 101-200 m, 50-100 m, and < 50 m, serving as a surrogate for TRAP. Six lifestyle behaviors (smoking, drinking, exercise, body mass index, sleep duration, and dietary diversity) were taken into account to calculate healthy lifestyle scores. The scores ranged from zero to six and were then divided into three groups: healthy (5-6), intermediate (2-4), and unhealthy (0-1). Logistic regression models were applied to investigate the joint effects of TRAP and healthy lifestyle scores on cognition.

RESULTS

Compared to participants living < 50 m from major roadways and adopting an unhealthy lifestyle, those living > 300 m from major roadways and adopting a healthy lifestyle had a significantly decreased risk of cognitive impairment. Stratified analysis indicated that the associations between TRAP and cognitive impairment were more pronounced among participants adopting an unhealthy lifestyle compared to the participants adopting a healthy lifestyle.

CONCLUSIONS

TRAP may impair cognitive function, and its detrimental impacts may be lessened by healthy lifestyles.

Association of household fuel use with hypertension and blood pressure among adult women in rural Bangladesh: A cross-sectional study

OBJECTIVES

This study aimed to determine the association of household fuel use with hypertension, systolic blood pressure (SBP), and diastolic blood pressure (DBP) among adult women.

METHODS

A cross-sectional survey through face-to-face interviews and blood pressure (BP) measurement were conducted among 2182 randomly selected women (1236 solid fuel users and 946 clean fuel users) in rural areas of Bangladesh.

RESULTS

Overall, 21% of women were hypertensive. Mean SBP and DBP for the study population were 121.27 mmHg (SD ± 15.43) and 76.18 mmHg (SD ± 12.00), respectively. Hypertension was found significantly (p = .006) higher among solid fuel users (23%) compared to clean fuel users (18%). Women using solid fuels have a 35% higher chance (AOR: 1.35, CI: 1.10-1.80) of having hypertension and have more than twice the risk of developing elevated SBP (AOR: 2.01, CI: 1.55-2.95) relative to women using clean fuels for their daily cooking. The probability of hypertension (AOR: 1.39, CI: 1.17-1.60) and elevated SBP (AOR: 1.35, CI: 1.10-1.61) increased significantly for every hour of fuel use.

CONCLUSIONS

Using clean fuel, reducing the duration of daily cooking time, and improved cooking facilities may help minimizing hypertension and ultimately cardiovascular disease risk among women.

Association between housework and the risk of dementia among older Chinese adults: a prospective cohort study

OBJECTIVES

Physical activity (PA) is known to improve physical functioning and mental health and to reduce the incidence of dementia. However, studies of the effects of non-recreational PA on the incidence of dementia, especially in East Asian populations, remain limited. In this study, we evaluate the association of doing housework with the risk of dementia among participants in the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

METHODS

The analysis was conducted with data from 7,237 CLHLS participants age over 65 obtained in 2008/2009, 2011/2012, 2014, and 2018. The frequency of housework performance was classified into four groups. A Cox proportional-hazards model was used to examine the association of the baseline housework frequency with the incidence of dementia, with adjustment for demographic and socioeconomic characteristics and lifestyle and health conditions.

RESULTS

The adjusted multivariate model showed that the incidence of dementia was lower among participants who did housework almost every day than among those who rarely or never did housework (hazard ratio = 0.49; 95% confidence interval, 0.39-0.61). The subgroup and sensitivity analyses yielded similar results.

CONCLUSION

A high frequency of housework performance was associated with a reduced incidence of dementia among older Chinese adults, especially those who did not exercise regularly. The encouragement of engagement in housework would be a cost-effective measure promoting healthy aging in the Chinese population.

Association of cardiovascular health at old age with all-cause mortality: a prospective cohort study in China

BACKGROUND

Cardiovascular disease has become the leading cause of death worldwide, but there is a lack of data on whether cardiovascular health (CVH) is associated with elderly mortality in China. We investigated the relationship between the ideal CVH score of Chinese elderly and the all-cause mortality.

METHODS

The Beijing Elderly Comprehensive Health Cohort Study included a total of 4,499 participants aged 60 years and above. The CVH metric was calculated at baseline and had a score ranging from 0 to 12. The relationship of CVH metrics with all-cause mortality was investigated using Cox proportional hazard regression analysis. The robustness of results was tested using subgroup and sensitivity analysis.

RESULTS

The median CVH score among participants was 8.00 (2.00), with only 8.0% scoring 11-12 points. 667 deaths were observed during an average follow-up time of 8.2 years. Participants with a CVH score of 11-12 had a decreased risk of all-cause mortality when compared to those with a CVH score of 0-4(HR = 0.584, 95% CI: 0.373-0.913). Participants had a 7.5% lower risk of all-cause death with each unit higher CVH score (HR = 0.925, 95%CI: 0.885-0.967) with a linearly decreasing trend (P nonlinear = 0.575). The relationships were greater in younger elderly people and stroke patients (P interaction = 0.011 and 0.037. respectively). The consistency of significant trends in sensitivity analysis shows the robustness of association (P trend < 0.001).

CONCLUSIONS

Among the Chinese elderly, there was a linear relationship between improving CVH scores and a lower risk of all-cause mortality. Because of the enormous benefits brought by one point, strategies are essential for improving cardiovascular health attainment.

TRIAL REGISTRATION

This study was registered at China Clinical Trial Registration Center (ChiCTR2100049866).

Association of cooking fuel use with risk of cancer and all-cause mortality among Chinese elderly people: a prospective cohort study

When cooking with biomass and fossil fuels, their incomplete burning can lead to air pollution, which can trigger pernicious effects on people's health, especially among the elderly, who are more vulnerable to toxic and harmful environmental damage. This study explored the association between different cooking fuel types and the risk of cancer and all-cause mortality among seniors constructing Cox regression models. Data were obtained by linking waves of 6, 7, and 8 of the Chinese Longitudinal Healthy Longevity Survey, which included a total of 7269 participants who were 65 years old and over. Cooking fuels were categorized as either biomass, fossil, or clean fuels. And the effects of switching cooking fuels on death risk were also investigated using Cox regression models. The results indicate that, compared with the users of clean fuels, individuals using biomass or fossil fuels were at a greater death risk for cancer [HR (95% CI): biomass, 1.13 (1.05-1.20); fossil, 1.16 (1.06-1.25)] and all causes [HR (95% CI): biomass, 1.29 (1.16-1.42); fossil, 1.32 (1.22-1.50)]. Furthermore, compared with sustained users of biomass fuels, individuals converting from biomass to clean fuels significantly reduced death risk for cancer [HR (95% CI): 0.81 (0.72-0.95)] and all causes [HR (95% CI): 0.76 (0.64-0.93)]. Similarly, all-cause death risk [HR (95% CI): 0.77 (0.62-0.93)] was noticeably reduced among these participants converting from fossil to clean fuels than persistent users of fossil fuels. Subgroup analyses revealed that males had a greater cancer and all-cause death risk when exposed to unclean fuels. These findings can inform the development of policies and the implementation of measures related to cooking fuel use to promote the health of older people and reduce the burden of disease on society.

Tooth loss, denture use, and all-cause and cause-specific mortality in older adults: a community cohort study

Objectives

The available evidence on the connections between tooth loss, denture use, and mortality from all causes or specific causes among older adults is inconclusive. Therefore, we aimed to investigate the association between tooth loss, denture use, and all-cause and cause-specific mortality in older adults.

Methods

A cohort of 5,403 participants aged 65 and older were recruited in the 2014 Chinese Longitudinal Healthy Longevity Survey wave and followed up in the 2018 wave. Cox proportional hazard models were used to examine the association between the number of natural teeth, denture use, and all-cause and cause-specific mortality.

Results

During a mean (SD) follow-up of 3.1  years (1.3), 2,126 deaths (39.3%) occurred. Individuals with 0 and 1-9 teeth had higher mortality due to all-cause, cardiovascular disease (CVD), cancer, and other causes (all p-trend <0.05) than those with 20+ teeth. At the same time, no association was found with respiratory disease mortality. Participants who used dentures had lower mortality due to all causes [hazard ratios (HR) 0.79, 95% confidence intervals (CI) 0.71-0.88], CVD (HR 0.80, 95% CI 0.64-1.00), respiratory disease (HR 0.66, 95% CI 0.48-0.92), and other causes (HR 0.77, 95% CI 0.68-0.88) than those without dentures. Joint analysis revealed that older adults with fewer natural teeth and no dentures had higher mortality. Additionally, interaction analyses showed that the effects of the number of natural teeth on all-cause mortality were more pronounced in older adults aged <80  years (p-value for interaction = 0.03).

Conclusion

Having fewer natural teeth, particularly less than 10 teeth, is linked to an increased risk of mortality from all causes, including CVD, cancer, and other causes, but not respiratory disease. The use of dentures would mitigate the adverse impact of tooth loss on all-cause and some cause-specific mortality.

Findings of indoor air pollution and childhood obesity in a cross-sectional study of Chinese schoolchildren

BACKGROUND

Air pollution exposures are increasingly suspected to influence the development of childhood adiposity, especially focusing on outdoor exposure, but few studies investigated indoor exposure and childhood obesity.

OBJECTIVES

We aimed to examine the association between exposure to multiple indoor air pollutants and childhood obesity in Chinese schoolchildren.

METHODS

In 2019, we recruited 6499 children aged 6-12 years from five Chinese elementary schools in Guangzhou, China. We measured age-sex-specific body mass index z score (z-BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) on standard procedures. Four different indoor air pollution (IAP) exposures, including cooking oil fumes (COFs), home decoration, secondhand smoke (SHS), and incense burning, were collected by questionnaire and then converted into an IAP exposure index with four categories. Association between indoor air pollutants and childhood overweight/obesity as well as four obese anthropometric indices were assessed by logistic regression models and multivariable linear regression models, respectively.

RESULTS

Children exposed to ≥3 types of indoor air pollutants had higher z-BMI (coefficient [β]:0.142, 95% confidence interval [CI]:0.011-0.274) and higher risk of overweight/obesity (odd ratio [OR]:1.27, 95%CI:1.01-1.60). And a dose-response relationship was discovered between the IAP exposure index and z-BMI as well as overweight/obesity (p_{for trend}<0.05). We also found that exposure to SHS and COFs was positively associated with z-BMI and overweight/obesity (p < 0.05). Moreover, there was a significant interaction between SHS exposure and COFs on the higher risk of overweight/obesity among schoolchildren. Boys appear more susceptible to multiple indoor air pollutants than girls.

CONCLUSIONS

Indoor air pollution exposures were positively associated with higher obese anthropometric indices and increased odds of overweight/obesity in Chinese schoolchildren. More well-designed cohort studies are needed to verify our results.

Gender differences in the association between sensory function and CIND among Chinese elderly: Based on CLHLS

OBJECTIVE

To explore the gender differences of the association between sensory impairment (SI) and the risk of cognitive decline and possible cognitive impairment, no dementia (CIND).

METHOD

Data were drawn from three waves of the nationally representative survey of China Longitudinal Healthy Longevity Survey (CLHLS) between 2011/12-2018 surveys, involving 6138 participants aged 65 or older who had no CIND at the baseline. Multivariate linear or logistic regression models were employed to examine the effect of SI on cognitive decline and CIND risk by gender stratification, respectively.

RESULTS

Hearing impairment and visual impairment were associated with lower MMSE scores, and the strength of the association was stronger in men than in women. Hearing impairment was related to an elevated risk of CIND both in men and women (Men: OR=2.46; 95% CI=1.81, 3.35; Women: OR=1.43; 95% CI=1.09, 1.88). However, the effect of visual impairment on CIND was statistically significant only in men (OR=1.43; 95% CI=1.09, 1.88). The risk of cognitive decline and CIND were significantly higher with single and dual SI than those without SI, except for women with single visual impairment.

CONCLUSION

SI is independently associated with cognitive decline and CIND risk, and the association differed by gender. Further researches should clarify the mechanism between SI and cognitive function among older adults, especially for gender differences.

Associations between cooking fuels and hypertension prevalence in Chinese adults: A prospective cohort analysis focusing on fuel transitioning

BACKGROUND

Using polluting cooking fuels is a suggested risk factor for hypertension. Transitioning to clean cooking fuels has occurred widely in China in the past 30 years. This provides an opportunity to examine whether the transition could reduce hypertension risk and to ascertain the inconsistent literature on the relationship between cooking fuels and hypertension prevalence.

METHODS

Initiated in 1989, the China Health and Nutrition Survey (CHNS) enrolled participants from 12 provinces in China. By 2015, nine waves of follow-up have been conducted. Based on self-reported cooking fuels, participants were classified into persistent clean fuel users, persistent polluting fuel users and those who transitioned from polluting fuels to clean fuels. Hypertension was defined as having systolic blood pressure (SBP) ≥ 140 mmHg, diastolic blood pressure (DBP) ≥ 90 mmHg, or self-reported current use of antihypertension medication.

FINDINGS

Among 12,668 participants, 3963 (31.28%) were persistent polluting fuel users; 4299 (33.94%) transitioned to clean fuels; and 4406 (34.78%) were persistent clean fuel users. During the period of follow-up (7.8 ± 6.1 years), hypertension was diagnosed in 4428 participants. Compared to persistent clean fuel users, persistent polluting fuel users had a higher risk for hypertension (hazard ratio [HR] 1.69, 95%CI 1.55-1.85), while those transitioned to clean fuels did not. The effects were consistent by gender and urbanicity, respectively. The HRs for hypertension were 1.99 (95%CI 1.75-2.25), 1.55 (95%CI 1.32-1.81) and 1.36 (95%CI 1.13-1.65) among those persistent polluting fuel users aged 18-44, 45-59 and ≥60 years old, respectively.

INTERPRETATION

Transitioning from using polluting fuels to clean fuels prevented an increase in hypertension risk. The finding highlights the importance of promoting the fuel transition as a risk-reduction strategy for reducing the disease burden from hypertension.

Association of biomass fuel use with the risk of vision impairment among Chinese older adults: a cohort study

Cooking with biomass fuels has been reported to have adverse effects on health. This study aims to explore the association between cooking with biomass fuels and vision impairment among Chinese older adults aged 65 years and above. This cohort study drew on data from the 2011/2012 wave and the 2014 follow-up wave of the Chinese Longitudinal Healthy Longevity Survey. Participants' visual function was examined through a vision screening test. Exposure to indoor biomass fuels was self-reported. Cox proportional hazards models were applied to explore the relationship between biomass fuel use and vision impairment. Additionally, we compared the risk of vision impairment between participants who switched cooking fuel types and those who did not. Subgroup and interaction analyses were conducted to explore the potential effect modifiers. A total of 4711 participants were included in this study. During the follow-up, 1053 (22.35%) participants developed vision impairment. Cooking with biomass fuels increased the risk of vision impairment by 40% (hazard ratio [HR]: 1.40, 95% confidence interval [CI]: 1.21-1.61). Participants who switched from clean fuels to biomass fuels had a greater risk of vision impairment than persistent clean fuel users (HR: 1.44, 95% CI: 1.03-2.00). Greater effect estimates were found in participants who lived in eastern and central China and urban residents. Cooking with biomass fuels resulted in a greater risk of vision impairment among Chinese older adults. This risk also existed in those who changed their cooking fuels from clean fuels to biomass fuels. Further studies with an objective assessment of biomass fuel combustion are required to confirm our findings.

Associations between Household Solid Fuel Use, Obesity, and Cardiometabolic Health in China: A Cohort Study from 2011 to 2018

This study aims to explore the longitudinal relationship between solid fuel use and CMD incidence based on a nationally representative follow-up cohort study. A total of 6038 participants of the China Health and Retirement Longitudinal Study (CHARLS) were enrolled in the study. CMD is a cluster of diseases that include heart disease, stroke, and type 2 diabetes. Cox proportional-hazards regression models were used to examine the association between solid fuel use and the incidence or multimorbidity of CMD. The interactions between overweight or obesity and household air pollution on CMD incidence were also investigated. In the present study, solid fuel use from cooking or heating, separately or simultaneously, was positively associated with CMD incidence. Elevated solid fuel use was significantly associated with a higher risk of CMD incidence (HR = 1.25, 95% CI: 1.09, 1.43 for cooking; HR = 1.27, 95% CI: 1.11, 1.45 for heating). A statistically significant interaction between household solid fuel and OW/OB on the incidence of CMD and Cardiometabolic multimorbidity was also observed (p < 0.05). Our findings show that household solid fuel is a risk factor for the incidence of CMD. Therefore, reducing household solid fuel use and promoting clean energy may have great public health value for the prevention of CMD.

Biomass using tribal women exhibited respiratory symptoms, hypertensive risks and abnormal pulmonary function

In rural areas of developing countries, solid fuels are still widely used for cooking, heating, and lighting purposes. This study investigates the effects of household air pollutants (HAPs) exposure on the occurrence of respiratory symptoms, blood pressure, and lung function. In this study, we randomly selected 123 (83 biomass and 40 clean fuel user) subjects to assess the impact of smoke generated from solid biomass fuel by assessing their health status along with the ventilation pattern of the kitchens and living rooms. HAPs (PM10, PM2.5, and CO) and different health parameters were measured along with monitoring of self-reported health symptoms for a consecutive period of eight months. Results revealed that the concentration of CO, PM2.5, and PM10 were found highest in biomass using households. Higher odds of the upper respiratory symptoms, runny nose (OR: 4.08, 95% CI: 1.22-22.14, p < 0.03), nasal congestion (OR: 9.07, 95% CI: 1.39-97.89, p < 0.01) and the odds of the lower respiratory symptoms like wheezing (OR: 1.62, 95% CI: 1.23-10.94, p < 0.01), breathlessness (OR: 4.44, 95% CI: 1.3-14.75, p < 0.01), chest tightness (OR: 4.89, 95% CI: 1.23-22.14, p < 0.03) and dry cough (OR: 3.661, 95% CI: 1.05-12.25, p < 0.04) were significantly higher in biomass fuel user. Similarly higher systolic (+11.41 mmHg), higher diastolic pressure (+3.3 mmHg), higher pulse pressure (+8.11 mmHg), and a 6 mmHg higher mean arterial pressure among biomass fuel using tribal women. The risk of hypertension was significantly (p < 0.03) higher (OR: 3.04; 95% CI: 1.18-7.89) among solid biomass fuel users. The lung abnormality was recorded 28.91% (OR: 5.02, 95% CI: 1.50 to 16.56, p < 0.01) among biomass fuel user. Finally, it is suggested that the use of efficient cookstoves, increase in cross ventilation, and cleaner fuel are urgently needed to curb the pollution load.

Joint modelling of systolic and diastolic blood pressure and its associated factors among women in Ghana: Multivariate response multilevel modelling methods

Elevated blood pressure is the leading cause of cardiovascular diseases related mortality and a major contributor to non-communicable diseases globally, especially in sub-Saharan Africa where about 74.7 million people live with hypertension. In Ghana, hypertension is epidemic with prevalence of over 30% and experiencing continuing burden with its associated morbidity and mortality. Using the 2014 Ghana Demographic and Health Survey, we analyzed data on 4744 women aged 15-49 years residing in 3722 households. We employed univariate and multivariate response multilevel linear regression models to analyze predictors of systolic blood pressure (SBP) and diastolic blood pressure (DBP). Geospatial maps were produced to show the regional distribution of hypertension prevalence in Ghana. Stata version 17 and R version 4.2.1 were used to analyze the data. Of the 4744 woman, 337 (7.1%) and 484 (10.2%) were found to be hypertensive on SBP and DBP, respectively. A combined prevalence of 12.3% was found. Older ages 25-34 (OR 2.45, 95%CI: 1.27, 3.63), 35-44 (OR 8.72, 95%CI: 7.43, 10.01), 45-49 (OR 15.85, 95%CI: 14.07, 17.64), being obese (OR 5.10, 95%CI: 3.62, 6.58), and having no education (OR -2.05, 95%CI: -3.40, -0.71) were associated with SBP. For DBP, we found the associated factors to be older ages 25-34 (OR 3.29, 95%CI: 2.50, 4.08), 35-44 (OR 6.78, 95%CI: 5.91, 7.64), 45-49 (OR 10.05, 95%CI: 8.85, 11.25), being obese (OR 4.20, 95%CI: 3.21, 5.19), and having no education (OR -1.23, 95%CI: -2.14, -0.33). Substantial residual household level differences in SBP (15%) and DBP (14%) were observed. We found strong residual correlation of SBP and DBP on individual women (r = 0.73) and household-level (r = 0.81). The geospatial maps showed substantial regional differences in the observed and reported hypertension prevalence. Interventions should be targeted at the identified high-risk groups like older age groups and those who are obese, and the high-risk regions.

Associations between Frailty and Ambient Temperature in Winter: Findings from a Population-Based Study

Frailty is an accumulation of deficits characterized by reduced resistance to stressors and increased vulnerability to adverse outcomes. However, there is little known about the effect of ambient temperature in winter on frailty among older adults, a population segment with the highest frailty prevalence. Thus, the objective of this study is to investigate the associations between frailty and ambient temperature in winter among older adults. This study was based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS) of older adults aged ≥65 years from the 2005, 2008, 2011, and 2014 waves. The 39-item accumulation of frailty index (FI) was used to assess the frailty status of the participants. The FI was categorized into three groups as follows: robust (FI ≤ 0.10), prefrail (FI > 0.10 to <0.25), and frail (FI ≥ 0.25). Generalized linear mixed models (GLMMs) were conducted to explore the associations between frailty and ambient temperature in winter. A generalized estimating equation (GEE) modification was applied in the sensitivity analysis. A total of 9421 participants were included with a mean age of 82.81 (SD: 11.32) years. Compared with respondents living in the highest quartile (≥7.5 °C) of average temperature in January, those in the lowest quartile (<−1.9 °C) had higher odds of prefrailty (OR = 1.35, 95% CI 1.17−1.57) and frailty (OR = 1.61, 95%CI 1.32−1.95). The associations were stronger among the low-education groups, agricultural workers before retirement, and non-current exercisers. Additionally, results from the GEE model reported consistent findings. Lower levels of ambient temperature in winter were associated with higher likelihoods of prefrailty and frailty. The findings on vulnerability characteristics could help improve public health practices to tailor cold temperature health education and warning information.

Association between household air pollution from solid fuel use and risk of chronic diseases and their multimorbidity among Chinese adults

BACKGROUND

Given the increasing burden of chronic conditions, multimorbidity is now a priority for public health systems worldwide. However, the relationship between household air pollution (HAP) exposure with multimorbidity remains unclear.

METHODS

We used three waves data (2011, 2013, and 2015) including 19,295 participants aged ≥ 45 years from the China Health and Retirement Longitudinal Study, to investigate the association between HAP exposure from solid fuel use for heating and cooking with the risk of chronic multimorbidity. Multimorbidity was defined as the coexistence of two or more of 15 chronic diseases (hypertension, diabetes, dyslipidemia, heart disease, stroke, cardiovascular disease, chronic lung disease, asthma, kidney disease, liver disease, digestive disease, cancer, psychiatric disease, memory-related disease, and arthritis). Multiple logistic regression investigated the association between solid fuel use for heating and cooking, separately or simultaneously, with the risk of multimorbidity. Poisson regression with quasi-likelihood estimation explored whether solid fuel exposure could increase the number of morbidities. Stratified analyses and sensitivity analyses examined the effect modification and robustness of the association.

RESULTS

Of the 19,295 participants (mean age: 58.9 years), 40.9 % have multimorbidity. Compared with participants who used clean fuels for heating and cooking, the risk was higher in mixed fuel (adjusted odds ratio, aOR = 1.26, 95 %CI:1.16-1.36) and solid fuel users (aOR = 1.81, 1.67-1.98) separately. HAP from solid fuel use was positively associated with an increased number of morbidities (adjusted β = 0.329, 0.290 to 0.368), after controlling for confounders. Those living in a one-story building, with poor household cleanliness have a higher risk of multimorbidity. No significant modifications of those associations by the socio-demographic and behaviour characteristics was observed.

CONCLUSIONS

HAP from solid fuel use is associated with a high risk of chronic multimorbidity in Chinese adults. Our findings provide important implications for reducing chronic disease burden by restricting solid fuel use.

Association of Household Utility of Cleaner Fuel With Lower Hypertension Prevalence and Blood Pressure in Chinese Adults

Objectives: To investigate whether lower hypertension prevalence or blood pressure was associated with cleaner household fuel usage for cooking and heating among Chinese adults. Methods: We enrolled 44,862 Chinese adults at the baseline of the prospective urban and rural epidemiology (PURE) study in China during 2005-2009, as a subset of the PURE-global China site. Multilevel logistic regression and generalized linear mixed models were conducted to estimate the adjusted odds ratio (AOR) and regression coefficient for hypertension and blood pressure respectively, while subgroup analysis by ambient PM2.5 concentration and location was also examined. Results: Compared with the least clean household solid fuel group, gas (AOR = 0.91, 95% CI: 0.83, 0.99) or electricity (AOR = 0.72, 95% CI: 0.60, 0.87) was associated with significantly lower levels of hypertension prevalence and blood pressure, and a similar pattern of the association was consistently observed among participants with high ambient PM2.5 exposure and those living in urban areas. Conclusion: Household utility of cleaner fuel type was associated with lower hypertension prevalence and blood pressure in Chinese adults. Our study urges the utilization of cleaner household energy to mitigate the burden of hypertension.

Physical activity attenuates the association between household air pollution and health-related quality of life in Chinese rural population: the Henan Rural Cohort Study

BACKGROUND AND PURPOSE

Limited research focused on the association between household air pollution (HAP) and health-related quality of life (HRQoL). This study aimed to investigate the association of HAP with HRQoL and the effect modification of physical activity.

METHOD

A total of 16,761 eligible participants were derived from the Henan Rural Cohort Study. Based on structured questionnaires, HAP was assessed by fuel type, cooking duration and kitchen ventilation; HRQoL was measured with utility index and VAS score from the European Quality of Life Five Dimension Five Level Scale (EQ-5D-5L); physical activity was assessed by the International Physical Activity Questionnaire. Generalized linear models and tobit regression models were utilized to explore the relationship of HAP with HRQoL. Further sensitivity analyses were conducted using structural equation models.

RESULTS

Compared with those who cooked with clean fuels, short-duration, or good kitchen ventilation, participants who cooked with solid fuels, long-duration, and poor ventilation had lower utility index and VAS score (All P < 0.001). The decrease in utility index for solid fuel users vs. clean fuel users were 0.06 [95%confidence interval (CI) 003, 0.08], 0.03 (95%CI 0.01, 0.04) and 0.02 (95%CI 0.01, 0.04) in low, moderate and high physical activity group, respectively, which decreased with physical activity levels (Pfor interaction < 0.05). Similar results were observed in associations of kitchen ventilation with utility index and VAS score.

CONCLUSION

HAP negatively associated with HRQoL in rural population, and potential intervention aimed at maintaining adequate physical activity.

TRAIL REGISTRATION

The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 06 July, 2015. http://www.chictr.org.cn/showproj.aspx?proj=11375 .

Association between playing cards/mahjong and risk of incident dementia among the Chinese older adults: a prospective cohort study

Objectives: Studies have shown that the frequent participation of the elderly in cognitive stimulation activities is associated with a reduced risk of dementia, but the prospective evidence of this association is limited.

Methods: We used data from a prospective cohort study of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), and included 11,821 community-living Chinese individuals aged 65 years or older at 2008 baseline who were free of dementia, and were followed up every 2–3 years until 2018. Cox proportional hazards models were applied to generate the hazard ratios (HRs) and 95% confidence intervals (CIs) for analyzing the associations between the frequency of playing cards/mahjong and the incidence of dementia.

Results: A total of 821 participants were diagnosed with dementia during the 10-year follow-up. The average age of patients with dementia and non dementia were 89 and 90 years old, respectively. Compared with participants who rarely or never played cards/mahjong, participants who played cards/mahjong almost every day had a significantly lower risk of dementia (HR = 0.63; 95%CI, 0.42–0.95) after the multivariable-adjusted model. Similar results were observed in subgroup analyses based on sex (male: HR = 0.52, 0.28–0.96; female: HR = 0.62, 0.36–0.98), age (<85years: HR = 0.55, 0.32–0.89), regularly exercise (yes: HR = 0.44, 0.28–0.87) and MMSE score [above median (25): HR = 0.66, 0.41–0.92].

Conclusions: Playing cards/mahjong in the elderly may contribute to reducing the risk of dementia.

Association of cooking fuel with incident hypertension among adults in China: A population-based cohort study

With an increasing prevalence of hypertension, indoor air‐pollution factors began to attract extensive attention. However, the association of cooking fuel with the incidence of hypertension was inconsistent. The aim of this study was to investigate the association of household air‐pollution caused by cooking fuel with the incidence of hypertension. Data were derived from the China Health and Nutrition Survey. Participants aged 18 years or older were eligible. A validated questionnaire was used to collect the information on the type of cooking fuel, including electricity, natural gas, coal, and wood/charcoal. Participants with a systemic blood pressure (SBP) ≥ 140 mmHg or /and a diastolic blood pressure (DBP) ≥ 90 mmHg without use of anti‐hypertensive medications, or participants with an SBP/DBP < 140/90 mmHg but having hypertensive history or currently being taking anti‐hypertensive medication were identified as hypertension. Multilevel Cox regressions were employed to examine the association of cooking fuel with incident hypertension. Compared to participants using electricity, participants using wood/charcoal had a higher incidence of hypertension (HR: 1.581; 95% CI: 1.373‐1.821; and P < .001), which was independent of sex and living areas. Furthermore, this significant association was observed only in the participants aged 18–39 years (HR: 1.443; 95% CI: 1.131‐1.840; and P = .003). Compared to participants using non‐polluting energy, participants using solid fuel were more likely to develop hypertension (HR: 1.309; 95% CI: 1.191‐1.439; and P < .001). In conclusion, household air‐pollution was associated with the incidence of hypertension among Chinese adults. Using wood/charcoal or solid fuel in youth was associated with a higher incidence of hypertension later in life.

Relationship of indoor solid fuel use for cooking with blood pressure and hypertension among the elderly in China

Indoor air pollution caused by solid fuel use for cooking affects 2.5 billion people worldwide and may elevate blood pressure (BP) and increase the burden of hypertension. Although the elderly are the most at risk of an elevated BP and hypertension, few studies have evaluated the effect of indoor solid fuel use for cooking on BP in persons over the age of 65. Therefore, in this study, we randomly selected 8067 elderly people over 65 years of age from the 2018 Chinese Longitudinal Healthy Longevity Survey to determine the impact of indoor solid fuel use on BP/hypertension. The results showed that, compared with those who cooked with clean fuel, those who cooked with solid fuel had a 1.87 mmHg higher systolic blood pressure, a 0.09 mmHg higher diastolic blood pressure, a 0.97 mmHg higher pulse pressure, and a 1.22 mmHg higher mean arterial pressure. However, we did not find any association between indoor solid fuel use and hypertension. We further observed that northern China residents, women, people aged over 90 years, hypertensive and heart patients, and those with natural ventilation in the kitchen that used indoor solid fuel experienced a greater BP impact. Replacing solid fuel with clean fuel may be an important way to lower BP. Regarding this, priority access to clean fuel should be given to the susceptible population, including the elderly aged ≥ 75 years, northern China residents, women, and hypertensive and heart patients.

Interaction of biomass fuels use and metals exposure on hypertension: A prospective cohort study in rural areas along the Yangtze River, China

Humans maybe simultaneously exposed to multiple-metals and indoor air pollution in daily life. However, limited prospective studies have assessed the interaction between multiple metals exposure and biomass fuels use on hypertension in China. The prospective cohort study in rural areas along the Yangtze River included 2625 adults in 2014-2015, and they were followed up till 2019. Among 1248 rural residents who were without hypertension at baseline, 377 hypertension events (30.21%) were observed after 4.5 years of average follow-up time. First-morning urine samples of residents were collected at baseline, the association between urinary metals level and hypertension were assessed using quantile g-computation. Additionally, we also examined the effect of biomass fuels use, fuels switching, and cookstove ventilation on the association of metals exposure with hypertension. Quantile g-computation analyses showed a positive joint effect of 17 metals on hypertension, with the odds ratio (OR) of 1.68 (95% CI: 0.89, 3.14) when increasing all seventeen metals by one quartile, and cadmium, lithium, copper contributed the largest positive weights. Biomass fuels use can interact with cadmium exposure on hypertension with OR for interaction of 1.28 (95%CI: 1.00, 1.73), and increase the association between copper, manganese and zinc exposure and systolic blood pressure, lithium exposure and diastolic blood pressure at the follow-up visit. Moreover, switching from biomass fuels to clean fuels during follow up, cookstove ventilation can alleviate the risk of higher blood pressure from metals exposure. In rural areas along the Yangtze River, China, biomass fuels use for cooking can interact with multiple-metals exposure on hypertension. Residents who switched from biomass fuels to clean fuels and who used ventilation had a lower risk of hypertension. Further cohort studies are needed to clarify the mechanism of combined effects of metals exposure and biomass fuels use on the human health.

Mediating Factors Explaining the Associations between Solid Fuel Use and Self-Rated Health among Chinese Adults 65 Years and Older: A Structural Equation Modeling Approach

Exposure to indoor air pollution from cooking with solid fuel has been linked with the health of elderly people, although the pathway to their association is unclear. This study aimed to investigate the mediating effects between solid fuel use and self-rated health by using structural equation modeling (SEM) with the baseline data from Chinese Longitudinal Healthy Longevity Survey (CLHLS). We conducted a cross-sectional survey among 7831 elderly people aged >65 years from the CLHLS. SEM was used to analyze the pathways underlying solid fuel use and self-rated health. We estimated indirect effects of sleep quality (β = −0.027, SE = 0.006), cognitive abilities (β = −0.006, SE = 0.002), depressive symptoms (β = −0.066, SE = 0.007), systolic blood pressure (β = 0.000, SE = 0.000), and BMI (β = −0.000, SE = 0.000) on the association between solid fuel and the self-rated health using path analysis. Depressive symptoms emerged as the strongest mediator in the relationship between solid fuel use and self-rated health in the elderly. Interventions targeting sleep quality, cognitive abilities, depressive symptoms, systolic blood pressure, and BMI could greatly reduce the negative effects of solid fuel use on the health of the elderly population.

Indoor solid fuel use for cooking and the risk of incidental non-fatal cardiovascular disease among middle-aged and elderly Chinese adults: a prospective cohort study

OBJECTIVES

The harm of indoor air pollution to health has gradually attracted attention, but the effect of indoor air pollution from burning solid fuels on incidental non-fatal cardiovascular disease (CVD) is not well understood. Under these circumstances, this study examined the association between solid fuel use and incidental non-fatal CVD.

DESIGN

The prospective cohort study was conducted in 2011, 2013, 2015 and 2018.

SETTING

The nationally representative survey was conducted in 28 provinces of China.

PARTICIPANTS

This study included 13 544 middle-aged and elderly adults without CVD in the baseline survey, and they were followed for 7 years.

OUTCOME MEASURES

First incidence of non-fatal CVD (heart disease or stroke).

METHODS

Based on longitudinal data, Cox proportional hazards models were used to assess the effects of solid fuel use and persistent use on incidental CVD events.

RESULTS

During the 7-year follow-up period, there were 1533 non-fatal CVD cases. A total of 7310 (54%) participants used solid fuel for cooking at the baseline survey, and 2998 (41%) users continued to use solid fuel. Solid fuel use was associated with incidental non-fatal CVD (HR: 1.18; 95% CI: 1.05 to 1.32) compared with clean fuel, and persistent solid fuel use might lead to a higher risk of incidental non-fatal CVD (HR: 1.38; 95% CI: 1.18 to 1.61) and heart disease (HR: 1.49; 95% CI: 1.24 to 1.81). In the subgroup analysis, the relationship remained significant in the female, elderly, rural and hypertensive groups. However, we found no significant interaction between these risk factors and fuel use (all p<0.05).

CONCLUSIONS

This cohort study provides evidence for the effects of solid fuel use on incidental non-fatal CVD in middle-aged and elderly Chinese adults. Advocating for the use of clean energy and ventilation stoves is important to cardiovascular health.

Solid fuel use, socioeconomic indicators and risk of cardiovascular diseases and all-cause mortality: a prospective cohort study in a rural area of Sichuan, China

BACKGROUND

Estimates indicate that household air pollution caused by solid fuel burning accounted for about 1.03 million premature mortalities in China in 2016. In the country's rural areas, more than half the population still relies on biomass fuels and coals for cooking and heating. Understanding the health impact of indoor air pollution and socioeconomic indicators is essential for the country to improve its developmental targets. We aimed to describe demographic and socioeconomic characteristics associated with solid fuel users in a rural area in China. We also estimated the risk of cardiovascular disease and all-cause mortality in association with solid fuel use and described the relationship between solid fuel use, socioeconomic status and mortality. We also measured the risk of long-term use, and the effect of ameliorative action, on mortality caused by cardiovascular disease and other causes.

METHODS

We used the China Kadoorie Biobank (CKB) site in Pengzhou, Sichuan, China. We followed a cohort of 55 687 people over 2004-13. We calculated the mean and standard deviation among subgroups classified by fuel use types: gas, coal, wood and electricity (central heating additionally for heating). We tested the mediation effect using the stepwise method and Sobel test. We used Cox proportional models to estimate the risk of incidences of cardiovascular disease and mortality with survival days as the time scale, adjusted for age, gender, socioeconomic status, physical measurements, lifestyle, stove ventilation and fuel type used for other purposes. The survival days were defined as the follow-up days from the baseline survey till the date of death or 31 December 2013 if right-censored. We also calculated the absolute mortality rate difference (ARD) between the exposure group and the reference group.

RESULTS

The study population had an average age of 51.0, and 61.9% of the individuals were female; 64.8% participants (n = 35 543) cooked regularly and 25.4% participants (n = 13 921) needed winter heating. With clean fuel users as the reference group, participant households that used solid fuel for cooking or heating both had a higher risk of all-cause mortality: hazard ratio (HR) for: cooking, 1.11 [95% confidence interval (CI) 1.02, 1.26]; heating, 1.34 (95% CI 1.16, 1.54). Solid fuel used for winter heating was associated with a higher risk of mortality caused by cerebrovascular disease: HR 1.64 (95% CI 1.12, 2.40); stroke: HR 1.70 (95% CI 1.13, 2.56); and cardiovascular disease: HR 1.49 (95% CI 1.10, 2.02). Low income and poor education level had a significant correlation with solid fuel used for cooking: odds ratio (OR) for income: 2.27 (95% CI 2.14, 2.41); education: 2.34 (95% CI 2.18, 2.53); and for heating: income: 2.69 (95% CI 2.46, 2.97); education: 2.05 (95% CI 1.88, 2.26), which may be potential mediators bridging the effects of socioeconomic status factors on cardiovascular disease and all-cause mortality. Solid fuel used for cooking and heating accounted for 42.4% and 81.1% of the effect of poor education and 55.2% and 76.0% of the effect of low income on all-cause mortality, respectively. The risk of all-cause mortality could be ameliorated by stopping regularly cooking and heating using solid fuel or switching from solid fuel to clean fuels: HR for cooking: 0.90 (95% CI 0.84, 0.96); heating: 0.76 (95% CI 0.64, 0.92).

CONCLUSIONS

Our study reinforces the evidence of an association between solid fuel use and risk of cardiovascular disease and all-cause mortality. We also assessed the effect of socioeconomic status as the potential mediator on mortality. As solid fuel use was a major contributor in the effect of socioeconomic status on cardiovascular disease and all-cause mortality, policies to improve access to clean fuels could reduce morbidity and mortality related to poor education and low income.

Residential proximity to major roadway and progression in physical disability in older adults in China

Evidence of a connection between living near major roadway and adverse health outcome has come to light. However, little is known about the effect of residential traffic exposure on aging-related physical disability and whether this effect can be modified. We used data derived from Chinese Longitudinal Healthy Longevity Surveys in 2018, with a total of 15,771 participants aged ≥ 65. Residential proximity to major roadway was used as a surrogate for traffic-related air pollution and physical function was measured using basic and instrumental activities of daily living. Logistic regression models were adopted for the analyses. Compared with those living > 300 m from major road, participants living within 200 m had higher risk of poorer physical functioning. The peak odds ratio was observed in severe disability caused by 101-200 m distance (OR = 1.34, 95% CI: 1.08, 1.66). And this association got stronger with longer duration of living close to major road. In dichotomized analyses using 200 m as a cutoff point, the effect associated with living close to major road was greater in male and current smoker. Specially, poor physical function appears earlier in female, but less severe than that in male. The result emphasizes the adverse effect of residential proximity to major roadways to aging-related declines in health-especially for basic living ability. This association was more pronounced in male and current smokers, which cannot be reversed by lowering the indoor air pollution.

Indoor solid fuel use and renal function among middle-aged and older adults: A national study in rural China

Solid fuel use is the main source of indoor air pollution, especially in rural areas of developing countries. Nevertheless, the evidence linking indoor solid fuel use and renal function is very limited. Therefore, we investigated the association between indoor solid fuel use and renal function among middle-aged and older adults in rural China. Cystatin C (CysC) concentration of each participant was used to calculate the estimated glomerular filtration rate (eGFR). We used the baseline data to investigate the associations between solid fuel use for cooking and heating and eGFR through a linear-mixed effects model. Then, we applied the generalized linear-mixed effects model with binary distribution to examine the relationship between renal function decline and cooking fuel switching from 2011 to 2015. A total of 4959 participants were included at baseline, and 3536 participants were included in the follow-up analysis. Compared to participants who used clean fuel for both cooking and heating, the eGFR was significantly lower among participants who cooked with solid fuel and heated with clean fuel (β: -2.81; 95% CI: -5.53, -0.09). In the follow-up analysis, the risks of renal function decline for participants using solid fuel for cooking were significantly higher in males (OR: 2.74; 95% CI: 1.68, 4.49), smokers (OR: 5.70; 95% CI: 2.82, 11.55), and drinkers (OR: 7.11; 95% CI: 3.15, 16.02) compared to females, non-smokers, and non-drinkers. Moreover, 45-65 years aged participants (OR: 0.54; 95% CI: 0.33, 0.89) and non-drinkers (OR: 0.61; 95% CI: 0.41, 0.92) who switched from solid to clean cooking fuel had a lower risk of renal function decline. In conclusion, our findings show that household solid fuel use is likely to be an important risk factor for renal function decline in rural China. And switching to cleaner fuel may provide significant public health benefits.

Assessment of household air pollution exposure of tribal women

There is a growing evidence that the burning of unprocessed biomass fuels is associated with adverse health impacts. This study estimated the gaseous pollutants (CO, CO₂, O_3, SO₂, and NO₂) and particulate matters (PM_2.5 and PM₁₀) during the burning of biomass and liquefied petroleum gas (LPG) fuels and their impacts on the health of tribal women. The results revealed that the tribal women mainly used six types of unprocessed biomass fuels (dry leaves, cow dung cake, dry woods, twigs, rice straw, and agricultural residues) along with five types of traditional earthen stoves. The concentration of gaseous and PM was recorded as in the order of CO₂ > SO₂ > CO > O₃ and total suspended particulate matter (TSPM) > PM₁₀ > PM_2.5, respectively. The pollutant concentration inside the kitchen room for biomass users was significantly (p < 0.001) higher than LPG users. The biomass using tribal women might be suffering from higher cardiovascular risk than LPG users. The lung function study results also indicated that the mean values of forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and FEV₁/FVC were lower among biomass users than LPG users. The correlation study shows that tribal women who were exposed to biomass smoke were in a more vulnerable position than those who used LPG. Moreover, the toxicological risk among tribal biomass users was observed high (3.52) compared to LPG users (0.39). On the other hand, the Monte Carlo probabilistic simulation model for uncertainty analysis revealed that the mean value of Hazard Quotient (HQ) for PM_2.5 in kitchen room was observed as 4.31E-00 and 9.40E-01 for biomass and LPG users, respectively. Modelling study also revealed that exposure of duration and cooking time are extremely important for toxicological risk assessment. However, further long-term comprehensive studies are extremely important.

Household Air Pollution and High Blood Pressure: A Secondary Analysis of the 2016 Albania Demographic Health and Survey Dataset

Background: Hypertension is a significant public health problem in low- and middle-income countries (LMICs). This study aimed to examine the association between household air pollution (HAP) and blood pressure using data from the 2016 Albania Demographic Health and Survey (DHS). Methods: We computed the odds ratio (OR) for the prevalence of hypertension between respondents exposed to clean fuels (e.g., electricity, liquid petroleum gas, natural gas, and biogas) and respondents exposed to polluting fuel (e.g., kerosene, coal/lignite, charcoal, wood, straw/shrubs/grass, and animal dung). Result: The results show that participants exposed to household polluting fuels in Albania were 17% more likely to develop hypertension than those not exposed to household air pollution (OR = 1.17, 95% CI 1.10 to 1.24). Subgroup analysis revealed that the odds of hypertension were more significant among women (OR = 1.22, 95% CI 1.13 to 1.31), rural residents (OR = 1.12, 95% CI 1.04 to 1.22), and participants aged >24 years (OR = 1.35, 95% CI 1.12 to 1.62) who were exposed to household polluting fuels compared to their counterparts who were not exposed. In summary, the results of the study show significant associations between household air pollution and hypertension risk overall, especially among women, rural dwellers, and people aged >24 years in Albania. Conclusion: In this study, an association between household air pollution and the risk of hypertension was found, particularly among low-income households, those with no education, women, and those who live in rural areas.

Effects of household cooking with clean energy on the risk for hypertension among women in Beijing

Outdoor air pollution and indoor burning of biomass fuel can cause high blood pressure. However, little is known about the effects of cooking with clean energy on hypertension. We thus explored whether cooking with clean energy is associated with the risk for hypertension. The study used baseline data from 12,349 women from a large population-based cohort study in Beijing, China. Information on cooking habits, health status, and other characteristics was collected by questionnaire and physical examination. Fasting blood samples were collected to measure total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and homocysteine (HCY). An index of cooking exposure was constructed. Log-binomial regression models were used to estimate the association between cooking exposure and risk for hypertension. The prevalence of hypertension was 26.7%. Any cooking exposure at all was associated with an increased risk for hypertension with an adjusted prevalence ratio (aPR) of 2.27 (95% confidence interval [CI]: 2.01, 2.57). The risk for hypertension increased with increases in cooking frequency, time spent cooking, and the cooking index, all showing a dose-effect relationship (P < 0.001). An increased risk for hypertension was associated with both cooking using mainly electricity (aPR: 1.75, 95% CI: 1.41, 2.17) and cooking using mainly natural gas (aPR: 2.30, 95% CI: 2.03, 2.60). The cooking index was positively correlated with plasma concentrations of TC, TG, LDL-C, and HCY and negatively correlated with HDL-C. Abnormal levels of all these biomarkers were associated with an increased prevalence of hypertension after adjustment for confounding factors. Cooking with clean energy, mainly cooking habit, may contribute to an increased risk for hypertension among female residents of Beijing. Abnormal metabolism of lipids or HCY may be an important mechanism involved in the development of cooking-related hypertension.

Cooking with biomass fuels and mortality among Chinese elderly people: A prospective cohort study

This study used data from the Chinese Longitudinal Healthy Longevity Survey (n = 9765, age 65+) to investigate the impact of biomass fuels on the mortality of the Chinese elderly population. The association between biomass fuels and mortality was examined using a Cox proportional hazards model. We evaluated the difference in risk of death between those who switched fuel types from biomass to clean fuels and from clean to biomass fuels versus those who did not during the follow-up period. Participants who used biomass fuels had a higher risk of death than participants who used clean fuels (HR = 1.09, 95% CI: 1.01-1.17). For participants who switched cooking fuel types during the follow-up period, switching from biomass to clean fuels significantly reduced the risk of death (HR = 0.78, 95% CI: 0.67-0.91), while no evidence of an association between switching from clean to biomass fuels and risk of death was found (p > 0.05). Interactions and subgroup analyses indicated that effect estimates were greater for women and non-smokers. Biomass fuels may be associated with a higher risk of death among Chinese elderly. Research measuring personal exposure levels to indoor air pollution caused by biomass fuels combustion is required to confirm our results.

Limitations in activities of daily living increase the risk of stroke in older Chinese adults: a population-based longitudinal study

It remains unclear whether limitations in activities of daily living (ADL) increase the risk of stroke in older Chinese adults. This longitudinal study used data from the Chinese Longitudinal Healthy Longevity Survey to investigate the effects of limitations in ADL on the incidence of stroke in older adults. Between 2002 and 2011, 46,728 participants from 22 provinces in China were included in this study. Of participants, 11,241 developed limitations in ADL at baseline. A 3-year follow-up was performed to determine the incidence of stroke. During the 3-year follow-up, 929 participants (8.26%) and 2434 participants (6.86%) experienced stroke in the ADL limitations group and non-ADL limitations group, respectively. Logistic regression was used to analyze the effect of ADL limitations on the risk of stroke. The results showed that after adjusting for the confounding factors gender, age, weight, hypertension, diabetes, heart disease, natural teeth, hearing impairment, visual impairment, smoking, alcohol abuse, exercise, ethnicity, literacy, residential area, and poverty, the ADL limitations group had a 77% higher risk of developing stroke than the non-ADL limitations group. After propensity score matching, the ADL limitations group still had a 33% higher risk of developing stroke than the non-ADL limitations group (OR = 1.326, 95% CI: 1.174–1.497). These findings suggest that limitations in ADL are a stroke risk factor.

All-Cause Mortality Risk Associated With Solid Fuel Use Among Chinese Elderly People: A National Retrospective Longitudinal Study

Background: The adverse health effects of air pollutants are widely reported, and the elderly are susceptible to toxic environments. This study aimed to evaluate the association between use of solid fuels for cooking and mortality among the elderly. Methods: A total of 5,732 and 3,869 participants from the Chinese Longitudinal Healthy Longevity Survey were enrolled in two (2014 and 2018) and three surveys (2011, 2014, and 2018) of survey. Cooking fuel was divided into clean and solid fuel. Cox proportional hazards models were used to estimate the mortality hazard ratio (HR). Subgroup analyses were performed to assess the potential interaction effect. Results: Among the participants in the 2011-2018 survey, 53% reported using solid fuel. Such group was associated with a 9% increase in mortality risk relative to clean fuel users (HR = 1.09, 95% CI = 1.01-1.18). Among participants in the 2014-2018 survey, 339 reported a switch from solid to clean fuels and they were not at increased mortality risk relative to the 488 people that reported a stable use of clean fuels (HR = 1.14, 95% CI = 0.99-1.31) although the estimated HR was similar to the one for stable solid fuel users (HR = 1.19, 95%CI = 1.04-1.36 n = 509). Interaction and stratified analyses showed that solid fuel use had an impact on mortality in participants who were non-current smokers, had low dietary diversity scores, and were living in areas with high PM2.5 concentrations (>50 μg/m3) and city population below 8 million (P for interaction < 0.05). The association was robust in the three sensitivity analyses. Conclusion: The finding showed a clear association between solid fuel use and mortality among older Chinese, and an even stronger association between risk of mortality and solid fuel use among individuals exposed to high levels of PM2.5.

Associations of changes in late-life blood pressure with cognitive impairment among older population in China

Background

The cognitive impact of changes in late-life blood pressure is less clear. We aimed to investigate the association between late-life blood pressure changing pattern and risk of cognitive impairment.

Methods

Using data from the community-based Chinese Longitudinal Healthy Longevity Survey, change in systolic (SBP) or diastolic (DBP) blood pressure was calculated as the difference between follow-up and baseline, cognitive impairment was defined based on both the Mini-Mental State Examination and education level. The generalized additive model with penalized spline and multivariate logistic regression model were used, respectively, to examine the associations between continuous and categorized blood pressure changes with cognitive impairment at the follow-up wave.

Results

A total of 8493 Chinese elderly without cognitive impairment were included, with mean (standard deviation) age 80.6 (10.7) years. U-shaped associations between late-life blood pressure changes and risk of cognitive impairment were found, with only stable optimal blood pressure related to the lowest risk. For participants with baseline SBP around 130–150 mmHg, the adjusted odds ratio was 1.48 (1.13–1.93) for increasing follow-up SBP (> 150 mmHg), 1.28 (1.02–1.61) for decreasing follow-up SBP (< 130 mmHg), compared to stable follow-up SBP (130–150 mmHg). For participants with relative lower baseline DBP (< 80 mmHg), increasing their DBP to 80–90 mmHg during follow-up was associated with lower cognitive impairment risk (0.73 (0.58–0.93)), compared to steady low follow-up DBP (< 80 mmHg). Sex-specific analysis suggested that men were more vulnerable in term of SBP change.

Conclusions

Adhering to a stable optimal level of blood pressure in late-life is related to lower risk of cognitive impairment in Chinese elderly.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02479-1.

Lung Features in Individuals with Biomass Smoke Exposure Characterized by CT Scan and Changes in Pulmonary Function

Background and Objective

To determine the effects of BSE (biomass smoke exposure) on pulmonary and non-pulmonary changes in patients with COPD compared with normal individuals.

Methods

Using a cohort, we recruited 16 healthy individuals with BSE (BSE normal), 19 patients with BSE+COPD, 13 healthy individuals with cigarette smoke exposure (CSE normal), 25 patients with CSE+COPD, and 25 healthy controls. Patients with GOLD stage I and II COPD were included. Baseline data (demographic data, BSE or CSE, lung function, and CT findings) and follow-up lung function data were collected. CT parameters of emphysema, pulmonary small vessels, airway remodeling, pectoralis muscles, and erector spinae muscle were measured.

Results

Individuals with BSE were mainly women (32/35, 91.43%). Compared with the CSE+COPD group, the BSE+COPD group demonstrated slower lung function decline, increased lower lung emphysema, narrower airway lumen dimensions and increased airway wall thickening in the moderate and small airways (all P<0.05). Compared with healthy controls, the CSE normal and BSE normal groups exhibited significant reductions in pulmonary small vessel area and obvious airway remodeling in small airways (P<0.05). Compared with the BSE normal group, the BSE+COPD group showed significantly more severe emphysema and airway remodeling, as well as reduced left pectoralis major muscle area (all P<0.05).

Conclusion

Healthy individuals with BSE had reduced pulmonary small vessel area and evidence of airway remodeling; patients with BSE and COPD showed more severe emphysema, airway remodeling, and reductions in pectoralis major muscle area.

Clinical Trial Registration

ChiCTR-OO-14004264.

Exposure to biomass fuel is associated with high blood pressure and fasting blood glucose impairment in females in southern rural China

OBJECTIVES

We sought to investigate the association between household exposure to biomass fuel and metabolic syndrome (MetS) and its components including blood pressure, triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG) and waist circumference among females in southern rural China.

METHODS

We surveyed 1664 residents in the Chronic Disease and Risk Factors Surveillance, conducted in 14 districts of Guangdong province. We recorded the use of biomass fuel, MetS and its components, and other covariates by using a structured questionnaire. Logistic regression model and multivariate linear regression model were adopted for analysis.

RESULTS

Exposure to biomass fuel was significantly associated with an increase of systolic blood pressure (SBP) (β: 2.15, 95% confidence interval: 0.13 to 4.17) and FBG (β: 0.19, 95% confidence interval: 0.01 to 0.37) in the adjusted and unadjusted models (all P < 0.05). Among participants with exposure to biomass fuel, being overweight or obese was associated with an increased risk of having hypertension (odds ratio: 3.19, 95% confidence interval: 2.13 to 4.76) and higher FBG levels (odds ratio: 2.10, 95% confidence interval: 1.46 to 3.02). Exposure to biomass fuel was significantly associated with a decrease of the prevalence of central obesity (P < 0.05). However, exposure to biomass fuel was not associated with MetS, diastolic blood pressure and TG (all P > 0.05).

CONCLUSIONS

Exposure to biomass fuel is associated with an increase in blood pressure and FBG levels, but not MetS per se. Efforts should be made to protect females in southern rural China from the adverse effects associated with biomass fuel pollution.

Association between solid fuel use and cognitive decline among middle-aged and elderly Chinese adults: a longitudinal study

This study was conducted to investigate (1) the association between solid fuel use for cooking and cognitive function; (2) the moderating effects of gender and residential area on cognitive scores among solid fuel users; and (3) the effects of solid fuel use on cognitive decline among different gender and age subgroups in 2011–2018. A total of 5140 Chinese middle-aged and elderly participants were successfully followed for 7 years (2011–2018). Solid fuel use was self-reported as using solid fuel for cooking at home, and cognitive function was assessed by 4 parts: episodic memory, time orientation, numerical ability and picture drawing. After adjusting for covariates, solid fuel users had lower cognitive scores, and the moderation effects of gender and residence on cognitive function were significant among the solid fuel users. In addition, compared with the group of clean fuel users, solid fuel users had a faster decline rate of cognitive function among the subgroups of female and elderly people.

Household solid fuel use and peak expiratory flow in middle-aged and older adults in China: A large cohort study (2011-2015)

Indoor air pollution caused by solid fuel use in cooking and heating in China is common. The relationship between household solid fuel use and peak expiratory flow (PEF) in middle-aged and older adults in China has not been clarified. The aim of this study was to assess the relationship between long-term household solid fuel use (clean for both cooking and heating, solid for either cooking or heating, and solid for both cooking and heating) and PEF changes in middle-aged and older adults using a nationally representative prospective cohort. Covariance analysis was used to compare PEF changes in different indoor air pollution exposure groups. Separate analysis of cooking and heating as well as sub-group analyses by age, sex and smoking status were conducted, linear mixed growth model analysis was used to evaluate the association between cooking fuel type and PEF. A total of 6818 participants were enrolled in the cohort analysis. Results revealed that solid fuel use in cooking and heating separately or conjointly were associated with reduced PEF (solid fuel use in cooking: least square mean [LSM] = 19.9, 95% confidence interval [CI]: 11.5-28.2, P = 0.03; solid fuel use in heating: LSM = 19.4, 95% CI:11.2-27.5, P = 0.04; both solid fuel use: LSM = 17.6, 95% CI: 9.3-25.9, P for trend <0.0001), especially in participants aged >65 years (LSM = -9.22, 95% CI: 27.9-69.52, P for trend <0.0001), females (LSM = -6.41, 95% CI: 19.12-6.30, P for trend <0.0001) and current or former smokers (LSM = -21.55, 95% CI: 36.14 to -6.97, P < 0.02). Compared to that of participants using clean fuels for cooking, PEF of participants using solid fuels were decreased by 3.5 l/min per 2 years over a 4-year follow-up. This cohort study highlights the adverse effects of indoor air pollution on lung function in middle aged and older adults in China.

Cardiovascular health impacts of wildfire smoke exposure

In recent years, wildland fires have occurred more frequently and with increased intensity in many fire-prone areas. In addition to the direct life and economic losses attributable to wildfires, the emitted smoke is a major contributor to ambient air pollution, leading to significant public health impacts. Wildfire smoke is a complex mixture of particulate matter (PM), gases such as carbon monoxide, nitrogen oxide, and volatile and semi-volatile organic compounds. PM from wildfire smoke has a high content of elemental carbon and organic carbon, with lesser amounts of metal compounds. Epidemiological studies have consistently found an association between exposure to wildfire smoke (typically monitored as the PM concentration) and increased respiratory morbidity and mortality. However, previous reviews of the health effects of wildfire smoke exposure have not established a conclusive link between wildfire smoke exposure and adverse cardiovascular effects. In this review, we systematically evaluate published epidemiological observations, controlled clinical exposure studies, and toxicological studies focusing on evidence of wildfire smoke exposure and cardiovascular effects, and identify knowledge gaps. Improving exposure assessment and identifying sensitive cardiovascular endpoints will serve to better understand the association between exposure to wildfire smoke and cardiovascular effects and the mechanisms involved. Similarly, filling the knowledge gaps identified in this review will better define adverse cardiovascular health effects of exposure to wildfire smoke, thus informing risk assessments and potentially leading to the development of targeted interventional strategies to mitigate the health impacts of wildfire smoke.

Association between solid fuel use and cognitive impairment: A cross-sectional and follow-up study in a middle-aged and older Chinese population

BACKGROUND

To date, few studies have focused on the influence of indoor air pollution on cognitive impairment. Thus, we aimed to explore the association of household fuel use, the major cause of household air pollution, with cognitive functioning among a sample of middle-aged and older Chinese individuals.

METHODS

A total of 10,372 and 8,397 participants from the China Health and Retirement Longitudinal Study (CHARLS) were enrolled in the cross-sectional and follow-up analyses, respectively. Cognitive functioning was evaluated via a structured questionnaire in three dimensions: orientation and attention, episodic memory, and visuo-construction. The associations between household solid fuel use (for cooking and heating) and cognitive functioning were elucidated by generalized linear models. Furthermore, we explored the combined effect of solid fuel use in cooking and heating and examined the effects of switching cooking fuel types on a 4-year change in cognitive functioning.

RESULTS

In the cross-sectional study, solid fuel use for cooking or heating, separately or simultaneously, was positively associated with cognitive impairment, after adjusting for potential confounders. Similarly, in the follow-up study, solid cooking fuel use was associated with a greater decline in cognitive score overall (β = -0.24, 95% confidence interval [CI]: -0.45, -0.04), mostly in the episodic memory (β = -0.19, 95% CI: -0.34, -0.03) and visuo-construction (β = -0.03, 95% CI: -0.05, -0.01) dimensions; solid heating fuel use was associated only with a greater decrease in the orientation and attention dimension (β = -0.13, 95% CI: -0.25, -0.01). A combined effect of household fuel use was also observed (P < 0.05). Moreover, subjects who switched from solid to cleaner cooking fuel displayed a significantly lower degree of cognitive decline for all dimensions than did persistent solid fuel users over a 4-year period (P < 0.05).

CONCLUSION

Our findings show that household solid fuel use is a risk factor for the development of cognitive impairment. Improving the structure of cooking fuel may therefore have great public health value for the prevention of cognitive impairment.