Relation of secondhand smoking to mild cognitive impairment in older inpatients

Behavioral and Cognitive Performance Following Exposure to Second-Hand Smoke (SHS) from Tobacco Products Associated with Oxidative-Stress-Induced DNA Damage and Repair and Disruption of the Gut Microbiome

Exposure to second-hand Smoke (SHS) remains prevalent. The underlying mechanisms of how SHS affects the brain require elucidation. We tested the hypothesis that SHS inhalation drives changes in the gut microbiome, impacting behavioral and cognitive performance as well as neuropathology in two-month-old wild-type (WT) mice and mice expressing wild-type human tau, a genetic model pertinent to Alzheimer's disease mice, following chronic SHS exposure (10 months to ~30 mg/m3). SHS exposure impacted the composition of the gut microbiome as well as the biodiversity and evenness of the gut microbiome in a sex-dependent fashion. This variation in the composition and biodiversity of the gut microbiome is also associated with several measures of cognitive performance. These results support the hypothesis that the gut microbiome contributes to the effect of SHS exposure on cognition. The percentage of 8-OHdG-labeled cells in the CA1 region of the hippocampus was also associated with performance in the novel object recognition test, consistent with urine and serum levels of 8-OHdG serving as a biomarker of cognitive performance in humans. We also assessed the effects of SHS on the percentage of p21-labeled cells, an early cellular marker of senescence that is upregulated in bronchial cells after exposure to cigarette smoke. Nuclear staining of p21-labeled cells was more prominent in larger cells of the prefrontal cortex and CA1 hippocampal neurons of SHS-exposed mice than in sham-exposed mice, and there was a significantly greater percentage of labelled cells in the prefrontal cortex and CA1 region of the hippocampus of SHS than air-exposed mice, suggesting that exposure to SHS may result in accelerated brain aging through oxidative-stress-induced injury.

Cohort study of the effects of occupation and environmental tobacco smoke on the incidence of Alzheimer's disease among seniors

INTRODUCTION

Alzheimer's disease (AD) is a disease caused by many factors including occupational and environmental factors. Secondhand smoke (SHS) can affect cognitive function. However, there is limited recent epidemiological research on how SHS and occupational factors affect AD in Zhejiang province.

METHODS

We established a cohort of an AD high-risk population. In 2018, a cohort of 1742 elderly aged ≥60 years was established. In 2020, the cohort was followed up, and a total of 1545 people participated in the two surveys. Data collection included demographic and economic information such as age, gender, occupation, education level etc., and relative health behavior information such as smoking, drinking and tea drinking, etc. Basic physical examination data included height, weight, blood pressure, etc. At the same time, related cognitive status was assessed. Cox proportional hazards regression models, both unadjusted and adjusted models, were used to determine associations between cohort characteristics and AD.

RESULTS

The results showed that SHS exposure and occupational characteristics were associated with an increased risk of cognitive impairments in seniors. Subgroups who used to work as blue-collar workers, who never worked, who kept standing for most of the time at work, and who were engaged in hard physical labor prior to retirement, had high incidence rates of AD.

CONCLUSIONS

It was revealed that SHS, standing for most of the time and hard physical labor were associated risk factors of AD among seniors, compared with white-collar work. We recommend that the government establish a community supervisory mechanism to persuade smokers to quit or control smoking.

Epidemiological Characteristics and Factors Associated with Alzheimer's Disease and Mild Cognitive Impairment among the Elderly in Urban and Rural Areas of Hubei Province

Utilize the prevalence, associated factors and population distribution of AD and MCI among residents of the Hubei province aged 60 years or over to prove that elderly people who study and communicate with others, take part in regular physical exercise and choose a healthy lifestyle, will prevent or slow the decline in cognitive ability. If elderly people study and communicate with others, take part in regular physical exercise and choose a healthy lifestyle, can prevent or slow the decline in cognitive ability. A cross-sectional study was used for the recruitment of subjects. The screened patients with AD and MCI were then selected as patients in a case−control study. A total of 4314 subjects were recruited into the study. The prevalence of AD and MCI was 1.44% and 10.04%, respectively. The prevalence of AD and MCI differed significantly as a function of age and gender (p < 0.05). The preventative factors for AD and MCI, separately, included a happy marriage (OR = 0.69, 95%CI: 0.36−1.35) and higher education (OR = 0.65, 95%CI: 0.55−0.78). The risk factors for AD and MCI, separately, included infrequent participation in social activities (OR = 1.00, 95%CI: 0.60−1.66) and infrequent communication with children (OR = 1.35, 95%CI: 1.09−1.69). The prevalence of AD for people aged 60 or over in the Hubei province was lower than the national average of 3.06%. The prevalence of MCI was within the national range (5.2−23.4%). The influencing factors of AD and MCI were associated with the participants’ social connections, lifestyle behaviors, somatic diseases and so on. The elderly people who study and communicate with others, take part in regular physical exercise and choose a healthy lifestyle will prevent or slow the decline in cognitive ability. The conclusion section has been replaced.

Higher blood cotinine level is associated with worse cognitive functioning in non-smoking older adults

Introduction

Secondhand smoke (SHS) is common in older adults; however, its cognitive effect is unclear. We aimed to examine the association between serum cotinine level and cognitive functioning among non-smoking older adults.

Materials and methods

A total of 2,703 older adults aged 60 and above from the National Health and Nutrition Examination (NHANES) Survey 2011-2014 were included. Serum cotinine level was analyzed in the laboratory. A level ≤10 ng/ml and a response of "no" to the question "Do you currently smoke?" were used to select non-smokers. Cognitive functioning was measured using the Consortium to Establish a Registry for Alzheimer's disease Word Learning subtest (CERAD-WL) immediate and delayed recall tests, the Animal Fluency test (AFT), and the Digit Symbol Substitution test (DSST). Multivariable linear regression models were constructed to examine the association between serum cotinine level quartile and test-specific and global cognition z scores adjusting for age, race/ethnicity, education, depressive symptoms, body mass index, alcohol use, smoking history, prevalent coronary heart disease (CHD), stroke, and systolic blood pressure.

Results

About half of the participants (mean age 70.5 years) were female (53.6%), non-Hispanic White (48.3%), and completed some college and above (50.2%). Multivariate linear regressions with a reference group being those in the 1st quantile (lowest) showed that participants in the 4th quartile (highest) of serum cotinine level had lower immediate recall [β = -0.16, 95% confidence interval (CI) = -0.29, -0.03], AFT (β = -0.19, 95% CI = -0.33, -0.05), DSST (β = -0.27, 95% CI = -0.39, -0.15), and global cognition (β = -0.26, 95% CI = -0.39, -0.14) z scores. Participants in the 3rd quartile had lower immediate recall (β = -0.16, 95% CI = -0.30, -0.02) and global cognition (β = -0.16, 95% CI = -0.29, -0.02) z scores. Participants in the 2nd quartile had lower delayed recall z scores (β = -0.16, 95% CI = -0.29, -0.02).

Conclusion

Higher serum cotinine level was associated with worse cognitive functioning in non-smoking older adults. Prevention and reduction of SHS in older adults may help protect their cognitive functioning.

Association Between Various Types or Statuses of Smoking and Subjective Cognitive Decline Based on a Community Health Survey of Korean Adults

Objectives

The relationship between smoking and subjective cognitive decline (SCD), which is defined as the subjective perception of cognitive decline, is not well known. This study aimed to investigate the relationship of various types of smoking, including E-cigarette smoking and the use of E-liquid, with the incidence of SCD among Korean adults.

Methods

We evaluated the 2018 Korean Community Health Survey data collected from community-dwelling people in Korea. A total of 104,453 non-smokers, 38,607 past smokers, and 26,776 current smokers with eligible data were included in the study. SCD was assessed using the Behavioral Risk Factor Surveillance System. The past or current smoking pack-years throughout each participant's entire life were calculated. Multiple regression analyses were carried out to estimate the adjusted odds ratios (ORs) as measures of the association between each type of smoking and SCD after adjustment for potential confounders.

Results

Compared to no exposure, passive smoking was associated with higher odds of SCD. Compared to non-smokers, past smokers had a higher OR for SCD; however, current smokers did not. There were no significant associations between passive smoking and SCD in the non-smoker and past smoker groups, but there was a significant relationship between them in the current smoker group. While the cumulative dose of smoking was correlated with an increased OR of SCD in each group of current smokers and past smokers, E-cigarette smoking and the use of E-liquid were not associated with higher ORs in the current smoker group.

Conclusion

Our findings support that passive smoking and past smoking are significantly associated with SCD and that more cumulative exposure to smoking is correlated with a higher OR of SCD.

Mild Cognitive Impairment and modifiable risk factors among Lebanese older adults in primary care

OBJECTIVE

Mild Cognitive Impairment (MCI) is an intermediate state between normal cognition and dementia. Identification of MCI and associated risk factors is important for early intervention. This study investigated the prevalence of MCI among Lebanese older adults and associated risk factors in primary care.

METHODS

For this cross-sectional study, 337 adults aged 60 years and older met inclusion criteria and were recruited at a primary care clinic associated with a tertiary medical center in Beirut, Lebanon. The validated Arabic version of the Montreal Cognitive Assessment, the 5-item Geriatric Depression Scale, and the Lawton Instrumental Activities of Daily Living Scale were administered. Data about sociodemographic, behavioral, and clinical characteristics was obtained.

RESULTS

There was no difference in the mean age between those with normal cognition and those with MCI (mean age 70.38 ± 7.4 and 72.12 ± 7.6 years, respectively). The prevalence of MCI was 14.8% (50 out of 337), 42% were males and 58% were women. Participants having more than 12 years of education (OR = 0.297; CI = 0.112-0.788; P = 0.015) were less likely to have MCI. Participants with history of smoking (OR = 2.599; CI = 1.266-5.339; P = 0.012) or at risk of depression (OR = 2.847; CI = 1.392-5.819; P = 0.004) were more likely to have MCI.

CONCLUSION

Identification of patients with history of smoking and at risk of depression may serve as an opportunity to offer intensive counseling and targeted treatment to delay the onset or progression of MCI to Alzheimer's disease.

Associations of particulate matter with dementia and mild cognitive impairment in China: A multicenter cross-sectional study

Ambient air pollution has been shown to be associated with the pathogenesis of dementia and mild cognitive impairment (MCI). However, few studies have examined these associations in well-characterized populations with low residential mobility, similar living habits, and a standardized assessment of both air pollution exposure and clinical outcome. This study examined the associations of long-term exposure to particulate matter (PM) air pollution with dementia and MCI, using data from the Chinese Veteran Clinical Research Platform. The cognitive function of elderly veterans from 277 communities in 18 Chinese cities was examined. Participants' daily exposures to aerodynamic diameters ≤2.5 μm (PM_2.5) and ≤10 μm (PM₁₀) during the 3 years prior to the survey were estimated using a satellite-based prediction. The adjusted odds ratios (ORs) and 95% confidence intervals of MCI associated with each 10 μg/m³ increase in PM_2.5 and PM₁₀ were 1.52 (1.39, 1.67) and 1.04 (1.00, 1.08), and those of dementia associated with PM_2.5 and PM₁₀ were 1.27 (1.11, 1.46) and 1.13 (1.05, 1.21), respectively. This demonstrates that long-term exposure to PM_2.5 and PM₁₀ can increase the prevalence of dementia/MCI among veterans in China. Higher ORs were observed for those with ≤9 years of educational attainment, those who actively attended physical activities, those who never smoked, former drinkers, and those who did not suffer from cerebral infarction. Improvement of ambient air quality, especially decreasing levels of PM_2.5, may help to decrease the risk of dementia/MCI. Given the statistically significant association between PM and cognitive impairment demonstrated here, future studies should focus on examining the causal effect of PM pollution on dementia and MCI.

Effects of Chronic Secondhand Smoke (SHS) Exposure on Cognitive Performance and Metabolic Pathways in the Hippocampus of Wild-Type and Human Tau Mice

BACKGROUND

Exposure to secondhand smoke (SHS) is a risk factor for developing sporadic forms of sporadic dementia. A human tau (htau) mouse model is available that exhibits age-dependent tau dysregulation, neurofibrillary tangles, neuronal loss, neuroinflammation, and oxidative stress starting at an early age (3-4 months) and in which tau dysregulation and neuronal loss correlate with synaptic dysfunction and cognitive decline.

OBJECTIVE

The goal of this study was to assess the effects of chronic SHS exposure (10 months' exposure to ∼30 mg/m3) on behavioral and cognitive function, metabolism, and neuropathology in mice.

METHODS

Wild-type (WT) and htau female and male mice were exposed to SHS (90% side stream, 10% main stream) using the SCIREQ® inExpose™ system or air control for 168 min per day, for 312 d, 7 d per week. The exposures continued during the days of behavioral and cognitive testing. In addition to behavioral and cognitive performance and neuropathology, the lungs of mice were examined for pathology and alterations in gene expression.

RESULTS

Mice exposed to chronic SHS exposure showed the following genotype-dependent responses: a) lower body weights in WT, but not htau, mice; b) less spontaneous alternation in WT, but not htau, mice in the Y maze; c) faster swim speeds of WT, but not htau, mice in the water maze; d) lower activity levels of WT and htau mice in the open field; e) lower expression of brain PHF1, TTCM1, IGF1β, and HSP90 protein levels in WT male, but not female, mice; and f) more profound effects on hippocampal metabolic pathways in WT male than female mice and more profound effects in WT than htau mice.

DISCUSSION

The brain of WT mice, in particular WT male mice, might be especially susceptible to the effects of chronic SHS exposure. In WT males, independent pathways involving ascorbate, flavin adenine dinucleotide, or palmitoleic acid might contribute to the hippocampal injury following chronic SHS exposure. https://doi.org/10.1289/EHP8428.

Association between secondhand smoke exposure and hypertension: nearly as large as smoking

: Active smoking is a widely accepted risk factor for cardiovascular disease and is recognized as a major public health problem. Passive smoking, also known as secondhand smoke exposure (SHSE), is thought to have similar cardiovascular consequences and the risk has been postulated to be equivalent to that of active smoking. A major component of this risk involves the connection with chronic hypertension. There are several population-based observational studies investigating the relationship between SHSE and chronic hypertension, all of which demonstrate a positive association. Given that SHSE appears to be a risk factor for chronic hypertension, SHSE should also be a risk factor for hypertensive end-organ disease. Many studies have sought to investigate this relationship, but this has yet to be fully elucidated. In this review, we focus on the current evidence regarding the association between SHSE and hypertension as well as exploration of the links between SHSE and hypertensive end-organ damage.

Passive Smoking Exposure in Living Environments Reduces Cognitive Function: A Prospective Cohort Study in Older Adults

There is currently no consensus regarding the effects of passive smoking exposure on cognitive function in older adults. We evaluated 7000 permanent residents from six regions within Zhejiang Province, China, aged ≥60 years, without cognitive impairment at baseline and during follow-up examinations for two years. The Chinese version of the Mini-Mental State Examination was used to assess the participants’ cognitive function. Multivariate regression analyses were carried out to calculate the adjusted relative risks (RRs) as measures of the association between passive smoking exposure and cognitive impairment after adjusting for potential confounders. The results showed an association between passive smoking exposure in the living environment and increased risk of cognitive impairment (RR: 1.16; 95% confidence interval (CI): 1.01–1.35). No dose–response relationship between the cumulative dose of passive smoking exposure (days) and cognitive impairment was observed. The results of stratified analyses suggested a harmful effect of passive smoking exposure on cognitive function in non-smokers (RR: 1.24; 95% CI: 1.06–1.46), but not in smokers (RR: 1.11; 95% CI: 0.71–1.92). Therefore, passive smoking exposure increased the risk of cognitive impairment in older adults, especially non-smokers. More effective measures to restrict smoking in the living environment should be developed and implemented.

Passive smoking as a risk factor for dementia and cognitive impairment: systematic review of observational studies

ABSTRACTBackground:Smoking is a well-established risk factor for dementia, but the effects of passive smoking are unclear. We aimed to examine links between passive smoking and dementia or cognitive impairment.

METHODS

We searched seven medical research databases: MEDLINE, Web of Science (Core Collection), Cochrane, EMBASE, PsycINFO, Scopus, and CINAHL Plus. Studies were included if they examined measures of passive smoking and either cognitive impairment or dementia.

RESULTS

Of 1,425 records found, nine papers of varying methodologies were included after screening against inclusion criteria. Eight papers reported weak associations between passive smoking and either cognitive impairment or dementia. One paper only found this association alongside carotid artery stenosis. The papers' quality was variable, with only two deemed high quality.

CONCLUSION

There is limited weak observational evidence linking passive smoking with an increased risk of cognitive impairment or dementia. However, the studies were methodologically diverse and of inconsistent quality, preventing firm conclusions.

Depression, anxiety and cognitive function in patients with type 2 diabetes: an 8-year prospective observational study

AIMS

Since depression, anxiety and cognitive function may be impaired in type 2 diabetes, we investigated the relationships between clinical and socioeconomic variables and these psychological dimensions.

METHODS

For an 8-year prospective observational study of 498 patients, 249 were not insulin-treated (NIT) and 249 were insulin-treated (IT). Demographic, socioeconomic and clinical data were monitored along with depression and anxiety (assessed by Zung questionnaire) and cognitive function by Mini Mental State Examination (MMSE).

RESULTS

After 8 years, 131 patients remained NIT (NIT-NIT), 179 remained IT (IT-IT), 47 switched to insulin (NIT-IT), 111 were lost to follow-up and 30 were died. In all groups, HbA1c remained stable, BMI, glucose and lipid profile improved, and foot ulcers and retinopathy worsened. Mild worsening in depression and anxiety scores was observed in the IT-IT patients only. On multivariate analysis, worsening of depression was associated with female gender, disease duration and being IT-IT, and worsening of anxiety with disease duration. Decreased MMSE was associated inversely with smoking and directly with being IT-IT.

CONCLUSIONS

Patients with type 2 diabetes are at relatively low risk of psycho-cognitive decline. However, being female and on long-term insulin treatment may be risk factors for psychological distress, suggesting that special attention is required for these patients.