Air pollution and cognition

APOE-ε4 Alleles Modify the Decline of MMSE Scores Associated With Time-Dependent PM2.5 Exposure: Findings From a Community-Based Longitudinal Cohort Study

OBJECTIVE

Limited research has explored the long-term effect of reduced PM2.5 exposure on cognitive function. This study aimed to investigate the effects of time-dependent PM2.5 exposure and the interactions of PM2.5 and aging on declines in Mini-Mental State Examination (MMSE) scores, in carriers and non-carriers of the APOE-ε4 allele.

METHODS

Participants aged over 60 were recruited for this cohort study, undergoing MMSE tests twice from the Taiwan Biobank Program from 2008 to 2020. Participants with dementia or baseline MMSE scores <24 were excluded. Annual PM2.5 levels were estimated using a hybrid kriging/land use regression model with extreme gradient boosting, treated as a time-dependent variable. Generalized estimating equations were used to assess the impacts of repeated PM2.5 on MMSE decline, further stratified by the presence of APOE-ε4 alleles.

RESULTS

After follow-up, 290 participants out of the overall 7,000 community residents in the Biobank dataset demonstrated incidences of MMSE declines (<24), with an average MMSE score decline of 1.11 per year. Participants with ε4/ε4 alleles in the APOE gene had significantly 3.68-fold risks of MMSE decline. High levels of PM2.5 across all visits were significantly associated with worsening of scores on the overall MMSE. As annual levels of PM2.5 decreased over time, the impact of PM2.5 on MMSE decline also slowly diminished.

CONCLUSION

Long-term PM2.5 exposure may be associated with increased risk of MMSE decline, despite improvements in ambient PM2.5 levels over time. Validation of these results necessitates a large-scale prospective cohort study with more concise cognitive screening tools.

Relationship between triglyceride-glucose index and cognitive function among community-dwelling older adults: a population-based cohort study

Background

The global increase in the aging population presents considerable challenges, particularly regarding cognitive impairment, a major concern for public health. This study investigates the association between the triglyceride-glucose (TyG) index, a measure of insulin resistance, and the risk of cognitive impairment in the elderly.

Methods

This prospective cohort study enrolled 2,959 participants aged 65 and above from the 2015 and 2020 waves of the China Health and Retirement Longitudinal Study (CHARLS). The analysis employed a logistic regression model to assess the correlation between the TyG index and cognitive impairment.

Results

The study included 2,959 participants, with a mean age of 71.2 ± 5.4 years, 49.8% of whom were female. The follow-up in 2020 showed a decrease in average cognitive function scores from 8.63 ± 4.61 in 2015 to 6.86 ± 5.45. After adjusting for confounding factors, a significant association was observed between TyG index quartiles and cognitive impairment. Participants in the highest quartile (Q4) of baseline TyG had a higher risk of cognitive impairment compared to those in the lowest quartile (Q1) (odds ratio [OR]: 1.97, 95% confidence intervals [CI]: 1.28-2.62, P<0.001).

Conclusion

The study highlights a significant connection between elevated TyG index levels and cognitive impairment among older adults in China. These findings suggest that targeted interventions to reduce the TyG index could mitigate cognitive impairment and potentially lower the incidence of dementia.

Cascade Bowl Multicavity Structure for In Situ Surface-Enhanced Raman Scattering Detection of Organic Gas Molecules

With the increasing emphasis on atmospheric environmental protection, it is crucial to find an efficient, direct, and accurate method to identify pollutant species in the atmosphere. To solve this problem, we designed and prepared the cascade multicavity (CMC) structure composed with silver nanoparticles (Ag NPs) as a surface-enhanced Raman scattering (SERS) substrate with favorable light transmittance and flexibility. The multicavity structure distributed on the surface introducing the homogeneous connecting holes endows the structure to more fully utilize the incident light while slowing the gas movement rate. Theoretical and experimental results have demonstrated that the Ag NPs/cascade multicavity (Ag-CMC) SERS substrate is a highly sensitive SERS substrate that can be used for in situ detection of gases under non-perpendicularly incident laser irradiation or bending of the substrate. We believe that the SERS substrate can provide a more efficient and feasible way for in situ detection of gaseous pollutants.

The link between cognitive health and neighbourhood: perceptions of the public, and of policy-makers, about problems and solutions

BACKGROUND

Growing evidence indicates associations between neighbourhood-related factors such as pollution, social isolation and physical inactivity, and cognition, that is, our ability to think clearly, learn and remember. The evidence raises the possibility of neighbourhood intervention playing a role in protecting population cognitive health. However, there is little understanding of these associations among the public and policy-makers, what they mean and how they might be acted on. In this study we explored perceptions of the public and policy-makers about influences of neighbourhood factors on brain functioning, and how they should inform policy.

METHODS

Qualitative methods were used in three phases; the study ran in parallel with a quantitative study looking at neighbourhood influences on cognition. In phase one, focus groups were conducted with middle-aged (40-69) members of the public to inform statistical modelling. In phase two, similar focus groups were held in four case study areas chosen based on the modelling results. In phase three, interviews with people in public health and policy roles were conducted, including people in the case study sites.

RESULTS

Participants described effects on their cognition from community, culture and social interactions, access to green spaces and nature, upkeep and safety of the area, and pollution, traffic and noise. Solutions included better local consultation and involvement in policy and planning, support for community interactions and active and public transport, and education on cognition. There was little awareness, but much interest, from local policy-makers and implementers, about links between cognition and place. Barriers to implementation included lack of: effective engagement with local communities, local funding and joined-up health and neighbourhood policy.

CONCLUSIONS

People can perceive impacts of neighbourhoods on brain functioning and suggest ways local areas can be improved to support cognitive health. There is support for the idea of population-level interventions to support cognitive health.

Association between the domestic use of solid cooking fuel and increased prevalence of depression and cognitive impairment in a big developing country: A large-scale population-based study

Background

Previous studies have suggested that air pollution affects physiological and psychological health. Using solid fuel at home is a significant source of indoor air pollution. The associations between solid fuel use and depressive symptoms and cognitive health were unclear among older adults from low- and middle-income countries (LMICs).

Methods

To evaluate the association of solid fuel use with depressive symptoms and cognitive health among older adults, we obtained data from the Longitudinal Aging Study in India (LASI) and excluded subjects younger than 60 years and without critical data (solid fuel use, depressive symptoms, and cognitive health). The 10-item Center for Epidemiologic Studies Depression Scale (CES-D-10) was used to assess depressive symptoms, with more than ten indicative of depression. Cognitive health was assessed using measures from the Health and Retirement Study (HRS), and subjects with the lowest 10th percentile were considered to have cognitive impairment. The participants' responses defined solid fuel use. Multivariable logistic regression, linear regression, subgroup analysis, and interaction tests were performed to appraise the relationship between solid fuel use and depression and cognitive impairment.

Results

A total of 29,789 participants over 60 years old were involved in this study. Almost half of the participants (47.5%) reported using solid fuel for home cooking. Compared with clean fuel use, solid fuel use was related to an increased prevalence of depression [odds ratio (OR) 1.09, 95% CI 1.03-1.16] and higher CES-D-10 scores (β 0.23, 95% CI 0.12-0.35) after fully adjusted covariables. Using solid fuel was also related to a higher risk of cognitive impairment (OR 1.21, 95% CI 1.11-1.32) and a lower cognitive score (β -0.63, 95% CI -0.79 to -0.47) compared with those who used clean fuel. In the subgroup analysis, the prevalence of depression increased in females and non-smokers. The association of solid fuel use with depression and cognitive impairment exists in subgroups of BMI, economic status, caste, living area, education, and drinking.

Conclusions

The use of solid fuel at home was associated with an increased prevalence of depression and cognitive impairment among older adults in India.

Current status and distribution of hip fractures among older adults in China

China is a middle-risk country for hip fracture at present, which differs from previous data that it was low-risk. By 2050, the total number of hip fractures in people older than 65 years is predicted to be 1.3 million.

INTRODUCTION

To assess hip fracture incidence in China and examine the heterogeneity of hip fracture in seven geographical regions of China.

METHODS

There were 238,230 hip fracture patients aged 65 years or older from 2013 to 2016 from a large national in-patients database (HQMS) involving 30.6 million hospitalizations. Taking into account the total national hospitalization rate per calendar year, we estimated the incidence of hip fracture per 100,000 residents older than 65 years in China overall and in seven geographical Chinese regions.

RESULTS

The proportion of men and women older than 65 years with hip fractures was 1.00:1.95. Between 2013 and 2016, the number of hip fractures per 100,000 people age 65+ was 278. China has vast territories; the number of hip fractures per 100,000 people over 65 years old was 202 in Northeast China and 374 in Northwest China. Northwest has higher altitude, lower population density, is less developed with lower urbanization than Northeast China which is low altitude, and highly urbanized.

CONCLUSIONS

China should no longer be regarded as a low-risk country for hip fracture. By 2050, the total number of hip fractures in people older than 65 years in China is predicted to be 1.3 million. Higher altitude areas had higher hip fracture rates than lower altitude, higher urbanized areas.

Short-term air pollution, cognitive performance, and nonsteroidal anti-inflammatory drug use in the Veterans Affairs Normative Aging Study

Air pollution, especially the fine particulate matter (PM2.5), may impair cognitive performance1-3, but its short-term impact remains poorly understood. We investigated the short-term associations of PM2.5 with the cognitive performances of 954 white males measured as the global cognitive function (GCF) and Mini-Mental State Examination (MMSE) scores, and further explored whether taking nonsteroidal anti-inflammatory drugs (NSAIDs) could modify their relationships. Higher short-term exposure to PM2.5 demonstrated non-linear negative associations with cognitive function. Compared with the lowest quartile of the 28-day average PM2.5 concentration, the 2nd, 3rd, and 4th quartiles were associated with 0.378-, 0.376-, and 0.499-unit decreases in GCF score, 0.484-, 0.315-, and 0.414-unit decreases in MMSE score, and 69%, 45%, and 63% greater odds of low MMSE scores (≤25), respectively. Such adverse effects were attenuated among NSAIDs users compared to non-users. This study elucidates the short-term impacts of air pollution on cognition and warrants further investigations on the modifying effects of NSAIDs.