Trajectories of occupational physical activity and risk of later-life mild cognitive impairment and dementia: the HUNT4 70+ study

Association between physical activity levels and mild cognitive impairment in Chinese older adults: a cross-sectional study from the China health and retirement longitudinal study

Background

Research indicates that mild cognitive impairment (MCI) in older adults is linked to physical activity; however, the relationship between varying levels of physical activity (PAL) and the risk of MCI needs further exploration.

Objective

This study explores the association and dose-response relationship between different levels of physical activity and MCI in older adults.

Methods

Using data from the 2020 China Health and Retirement Longitudinal Study (CHARLS), this cross-sectional analysis included 5,373 older adults aged 60 and above. Binary logistic regression models and restricted cubic spline (RCS) methods were employed to examine the association and dose-response relationship between different PAL levels and the risk of MCI in the overall population and subgroups. Sensitivity analyses were conducted to validate the robustness of the results.

Results

In the overall study population, compared to the lowest PAL quartile, participants in the second PAL quartile had a significantly reduced risk of MCI by 21.3% (p < 0.05). Given that the second PAL quartile had the lowest risk of MCI, a logistic regression model was constructed using the second quartile as the reference group. The results showed that, compared to the second PAL quartile, participants in the first and fourth PAL quartiles had significantly increased risks of MCI by 27.1% (p < 0.05) and 38.2% (p < 0.05), respectively. In subgroup analyses, compared to the second PAL quartile, female participants in the third and fourth PAL quartiles had significantly increased risks of MCI by 50.1% (p < 0.05) and 89.0% (p < 0.05), respectively; participants aged 60-74 in the first and fourth PAL quartiles had significantly increased risks of MCI by 29.4% (p < 0.05) and 42.2% (p < 0.05), respectively; and rural residents in the fourth PAL quartile had a significantly increased risk of MCI by 33.5% (p < 0.05). In the Chinese older adult population, a dose-response relationship was observed between physical activity and the risk of MCI. The RCS curve showed that as physical activity increased, the risk of MCI gradually decreased, reaching a beneficial point at 900 MET-min/week, with the lowest risk at approximately 1,600 MET-min/week. Beyond 1,600 MET-min/week, the risk of MCI began to rise, reaching a significant increase at 2,100 MET-min/week. Sensitivity analyses confirmed the robustness of the findings.

Conclusion

Physical activity levels between 900 and 2,100 MET-min/week are associated with a reduced risk of MCI in the Chinese older adult population. Using physical activity to predict the risk of MCI in this population is feasible, and moderate physical activity may be an effective strategy for preventing and managing MCI.

Relationships of Physical Activity and Type 2 Diabetes With Cognition in Mexican Americans and Non-Hispanic Whites

Problem, Research Strategy, and Findings: Low physical activity (PA) and Type 2 diabetes are associated with cognitive aging and Alzheimer's disease, but the evidence is inconsistent and particularly limited by ethnicity. The purpose of this study was to examine the relationships of PA and Type 2 diabetes with cognition in Mexican Americans and non-Hispanic Whites. The study was a cross-sectional analysis of the Health and Aging Brain Study-Health Disparities (n = 1,982-2,000 after removing outliers). Predictors included Rapid Assessment of Physical Activity and hemoglobin A1c (HbA1c). Episodic memory was assessed by Weschler Memory Scale-Third Edition Logical Memory and Spanish-English Verbal Learning Test, executive function by Weschler Memory Scale-Third Edition Digit Span and Digit Symbol Substitution Test, verbal fluency by FAS and animal naming, and global cognition by the Mini-Mental State Examination. Results show that aerobic PA and HbA1c were not associated with domain-specific, or global cognition, but strength/flexibility PA was associated with FAS (b = 0.404, 95% CI [0.023, 0.761]). Higher aerobic PA was associated with greater verbal fluency for Mexican Americans (b = 0.294, 95% CI [0.96, 0.497]) only. HbA1c was negatively associated with Mini-Mental State Examination (b = 0.838, 95% CI [0.008, 1.656]). For low HbA1c, the association between aerobic PA and Digit Symbol Substitution Test was significant for non-Hispanic Whites (b = 0.838, 95% CI [0.008, 1.656]) in comparison to Mexican Americans. Takeaway for Practice: The relationships between PA, Type 2 diabetes, and cognition vary by cognitive domains and ethnicity. Increasing aerobic activities may be particularly important for Mexican Americans who have elevated HbA1c to potentially improve fluency or executive function.

High-dimensional mediation analysis reveals the mediating role of physical activity patterns in genetic pathways leading to AD-like brain atrophy

BACKGROUND

Alzheimer's disease (AD) is a complex disorder that affects multiple biological systems including cognition, behavior and physical health. Unfortunately, the pathogenic mechanisms behind AD are not yet clear and the treatment options are still limited. Despite the increasing number of studies examining the pairwise relationships between genetic factors, physical activity (PA), and AD, few have successfully integrated all three domains of data, which may help reveal mechanisms and impact of these genomic and phenomic factors on AD. We use high-dimensional mediation analysis as an integrative framework to study the relationships among genetic factors, PA and AD-like brain atrophy quantified by spatial patterns of brain atrophy.

RESULTS

We integrate data from genetics, PA and neuroimaging measures collected from 13,425 UK Biobank samples to unveil the complex relationship among genetic risk factors, behavior and brain signatures in the contexts of aging and AD. Specifically, we used a composite imaging marker, Spatial Pattern of Abnormality for Recognition of Early AD (SPARE-AD) that characterizes AD-like brain atrophy, as an outcome variable to represent AD risk. Through GWAS, we identified single nucleotide polymorphisms (SNPs) that are significantly associated with SPARE-AD as exposure variables. We employed conventional summary statistics and functional principal component analysis to extract patterns of PA as mediators. After constructing these variables, we utilized a high-dimensional mediation analysis method, Bayesian Mediation Analysis (BAMA), to estimate potential mediating pathways between SNPs, multivariate PA signatures and SPARE-AD. BAMA incorporates Bayesian continuous shrinkage prior to select the active mediators from a large pool of candidates. We identified a total of 22 mediation pathways, indicating how genetic variants can influence SPARE-AD by altering physical activity. By comparing the results with those obtained using univariate mediation analysis, we demonstrate the advantages of high-dimensional mediation analysis methods over univariate mediation analysis.

CONCLUSION

Through integrative analysis of multi-omics data, we identified several mediation pathways of physical activity between genetic factors and SPARE-AD. These findings contribute to a better understanding of the pathogenic mechanisms of AD. Moreover, our research demonstrates the potential of the high-dimensional mediation analysis method in revealing the mechanisms of disease.

Life Course Patterns of Work History and Cognitive Trajectories Among Community-Dwelling Older Adults

OBJECTIVES

Prior research indicated that diverse work experiences in early and middle life stages are associated with cognitive function in later life. However, whether life course patterns of work history are associated with later life cognitive function in China remains unknown.

METHODS

Data were derived from the China Health and Retirement Longitudinal Study, and 5,800 participants aged 60 years or older were included. We used sequence analysis to identify the work history patterns between ages 18 and 60. Growth curve modeling was performed to evaluate how the work-history patterns are associated with global and domain-specific (i.e., mental intactness and episodic memory) cognitive function.

RESULTS

We identified 8 work patterns, distinguished by duration, transitions, timing, and sequence of work history. Compared with individuals exposed to lifelong agricultural work, those engaged in lifelong nonagricultural employed work had better cognitive function in later life and experienced slower rates of cognitive decline in both global cognitive function and the mental intactness domain. In addition, individuals who shifted from agricultural to nonagricultural employed work early (around age 30) had better global cognitive function in later life, whereas the association was not significant for such a transition later (around age 50).

DISCUSSION

Our study highlights the importance of the duration, sequence, and timing of transitions in work history for cognitive health among older Chinese. Future interventions and policies aimed at improving cognitive function should fully consider the cumulative and dynamic nature of work from a life course perspective.

Late-life physical activity, midlife-to-late-life activity patterns, APOE ε4 genotype, and cognitive impairment among Chinese older adults: a population-based observational study

BACKGROUND

Although physical activity (PA) has been linked to cognitive health, the nuanced relationships between different dimensions of PA and cognitive impairment remain inconclusive. This study investigated associations between late-life PA levels, midlife-to-late-life activity patterns, and cognitive impairment in Chinese older adults, considering potential moderation by apolipoprotein E (APOE) ε4 genotype.

METHODS

We analyzed baseline data from 6,899 participants (median age 68 years, 55.78% female) in the West China Health and Aging Cohort study, with 6,575 participants having APOE genotyping data. Late-life PA and midlife-to-late-life activity patterns were assessed using the Global Physical Activity Questionnaire and a standardized question, respectively. Cognitive function was evaluated using the Chinese version of Mini-Mental State Examination. Logistic regression models were used to examine associations.

RESULTS

Compared to low PA level, moderate (odds ratio [OR] = 0.74, 95% confidence interval [CI] = 0.55 ~ 0.99) and high PA levels (OR = 0.60, 95%CI = 0.48 ~ 0.75) were associated with lower risk of cognitive impairment. Engaging in work-, transport-, recreation-related, and moderate-intensity PA were each significantly associated with lower cognitive impairment risk. Maintaining activity levels from midlife to late life was associated with lower cognitive impairment risk compared to decreasing levels (OR = 0.75, 95%CI = 0.60 ~ 0.94). These associations were more pronounced in APOE ε4 non-carriers, with an interaction observed between APOE ε4 genotype and recreation-related PA (P-value = 0.04).

CONCLUSIONS

Our findings underscore the multifaceted benefits of PA in mitigating cognitive impairment risk among older Chinese adults. Public health strategies should focus on promoting overall late-life PA levels, especially moderate-intensity PA, and maintaining activity levels comparable to midlife, with potential for personalized interventions based on genetic risk profiles.

Tabata training in perspective

Originally developed as a specific form of exhaustive intermittent training involving 6-8 × 20 s of supramaximal-intensity cycling exercises with 10 s of recovery for athletes, Tabata training has become universally recognized around the world. The purpose of this review article is to provide a perspective on Tabata training and discuss how this popular style of intermittent training has evolved and been applied over the last ∼30 years. The article will review the original motivation behind Tabata training with relevance to concepts such as maximal accumulated oxygen deficit and maximal oxygen uptake (V̇o2max) and discuss how Tabata training has been adapted to involve sport-specific training and cross training. Studies of Tabata training on physiological responses and adaptations in muscle, blood vessels, bone, and brain across different populations will be reviewed. Finally, research on how Tabata-style training was applied to counteract inactivity during the COVID19 pandemic will be discussed. Evolving from the study of athletes, Tabata training represents an example of how high-intensity intermittent/interval training can be adapted and applied in various settings to enhance performance and health.

Alcohol consumption trajectories and risk of breast cancer among postmenopausal women: a Danish cohort study

Alcohol consumption is a risk factor for breast cancer (BC), yet little is known about longitudinal alcohol consumption patterns and risk of BC. This study aimed to investigate whether trajectory profiles of alcohol consumption across adulthood were associated with risk of first primary malignant BC in postmenopausal women. At baseline, 28,720 pre-and postmenopausal women aged 50-65 years from the Danish Diet, Cancer and Health Cohort reported their average alcohol intake over the past 12 months and their average alcohol intake at the ages of 20, 30, 40, and 50 years. Alcohol consumption trajectories were estimated using latent class mixed models. BC cases were identified through record linkage to the Danish Cancer Registry. To examine associations between alcohol consumption trajectories and BC, we fitted a proportional hazard model adjusted for potential confounding factors using data from 24,543 postmenopausal women without missing covariate information. We identified 4 alcohol consumption trajectory profiles. During a median follow-up of 16.5 years, 1,591 cases of BC occurred. A mean alcohol consumption trajectory of > 10 g/day was associated with higher risk of BC (HR: 1.65, 95%CI: 1.35-2.03) compared to a mean alcohol consumption trajectory of < 6 g/day. We found no association between trajectory profiles characterized by lower alcohol intakes in early adulthood followed by increasing consumption of alcohol in adulthood compared to a consistently low intake of alcohol. Postmenopausal women drinking consistently high amounts of alcohol throughout adulthood had a higher risk of BC compared to women with a consistently low intake of alcohol.

Sarcopenia risk in U.S. younger adults: the impact of physical activity intensity and occupational engagement-insights from a cross-sectional NHANES study

OBJECTIVE

This study aimed to investigate the associations between physical activity (PA) intensity, occupational PA engagement, and sarcopenia in younger adults.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) (from 2011 to 2018) were used for the study. PA data were extracted for the Global Physical Activity Questionnaire, and the ratio of limb muscle mass (ALM) to body mass index (BMI) was used to determine sarcopenia. Multiple logistic regression was performed, and dose-response curves were drawn to evaluate the associations.

RESULTS

Of the 8802 adults aged 20 to 59 years, 770 (8.7%) were identified as having sarcopenia. Compared to those in the reference group, the participants in the "low", "moderate", and "high" total METs groups had lower risks of sarcopenia (low: OR = 0.730, 95% CI = 0.583; 0.915; moderate: OR = 0.643, 95% CI = 0.485; 0.853; high: OR = 0.560, 95% CI = 0.457; 0.687). The risk of sarcopenia decreased in the high-intensity recreational PA group; however, such a significant association was observed only in the high-intensity occupational PA group. The relationship between total METs and sarcopenia showed a nonlinear U-shaped trend.

CONCLUSIONS

A greater intensity of PA is associated with a lower risk of sarcopenia among younger adults, regardless of whether moderate or vigorous PA is performed. Moreover, recreational PA may particularly advantageously contrast with occupational PA in lowering the risk of sarcopenia.

Association of cognitive performance with overall, dosage, intensity, and domain physical activity in aging: NHANES 2011-2014

BACKGROUND

The specific relationship between PA in detailed types and cognition is still unclear due to limited evidence. Our study aimed to investigate the relationship between cognitive performance and various aspects of physical activity, including overall activity, dosage, intensity levels [moderate physical activity (MPA), vigorous PA], and different domains of activity [occupational PA (OPA), transportation PA (TPA), and leisure-time PA (LTPA)] in older adults using data from the NHANES database.

METHODS

This cross-sectional analysis used data from 2 cycles of NHANES (2011-2014). PA was determined through participants' self-reports using the Global Physical Activity Questionnaire (GPAQ). Cognitive performance was evaluated by the presence of psychometric mild cognitive impairment (p-MCI), identified based on a composite measure derived from three cognitive tests including the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), the Animal Fluency test, and the Digit Symbol Substitution test (DSST). Logistic regression models were used to evaluate the association.

RESULTS

A total of 2588 participants aged 60 years or older were included, with an average age of 69.4 years and 48% being male. In the fully adjusted model, compared to no PA, performing 300 min of PA, and MPA were associated with 44%, and 33% reductions in the prevalence of p-MCI, respectively. Additionally, engaging in 1-149 min/week [OR 0.56, 95% CI (0.33-0.92)] and ≥ 300 min/week [OR 0.66, 95% CI (0.44-0.96)] of OPA, as well as ≥ 300 min/week [OR 0.56, 95% CI (0.36-0.86)] of LTPA, were also associated with a lower prevalence of p-MCI. Additionally, engaging in a diverse range of PA had better outcomes.

CONCLUSIONS

Our results suggested a positive association between higher levels of PA and enhanced cognitive performance. Different intensities and domains of PA have varying impacts on cognition. Future exploration, such as objectively measured PA and longitudinal studies were needed to validate our conclusion.

Differential associations of physical job demands with cognitive impairment in Korean workers aged 45 and older: a 14-year longitudinal study using the Korean Longitudinal Study of Aging (KLoSA)

OBJECTIVES

To investigate the association between subelements of physical job demands and cognitive impairment risk in middle-aged and older workers in Korea.

DESIGN

Longitudinal study using eight waves (2006-2020) of the Korean Longitudinal Study of Aging.

SETTING

Nationally representative sample of the Korean population aged 45 years and older.

PARTICIPANTS

2170 workers aged 45 and older at baseline.

PRIMARY OUTCOME MEASURES

Cognitive function was evaluated using the Korean version of the Mini-Mental State Examination and cognitive impairment was defined as a score below 24.

RESULTS

High physical strength demands were inversely associated with cognitive impairment (OR 0.31, 95% CI 0.14 to 0.68 for 'always' vs 'never' category). Conversely, frequent heavy lifting (OR 2.67, 95% CI 1.36 to 5.26) and bending, kneeling or squatting (OR 1.69, 95% CI 0.82 to 3.47) tasks were associated with increased impairment risk. Dose-response relationships were observed between all physical job demands and cognitive impairment, persisting among those with lower education but not among those with higher education.

CONCLUSIONS

Different types of physical job demands have varying relationships with cognitive impairment in middle-aged and older workers. Tasks requiring high physical strength may protect against cognitive impairment while tasks involving heavy lifting and bending, kneeling or squatting may increase the risk. These findings highlight the need for tailored interventions that consider the type of physical job demands and workers' educational levels to mitigate cognitive impairment risks. Further research is needed to explore the underlying mechanisms and validate these findings.

Effects of Occupational and Leisure-Time Physical Activity on the Risk of Dementia: Results From the Copenhagen City Heart Study

Leisure-time physical activity (LTPA) decreases the risk of dementia, whereas occupational physical activity (OPA) possibly increases the risk. Yet, previous findings are mixed. We therefore aimed to investigate the effect of LTPA and OPA, respectively, on dementia among men and women. In this observational, longitudinal study, we used data from the second wave of a population-based cohort from the municipality of Copenhagen as baseline. Data were collected in 1981-1983, and 10 343 participants were followed until the end of 2016. LTPA and OPA were self-reported, and information on dementia diagnoses and redemption of dementia medication was obtained at an individual level from national health registers. We used Poisson regression to analyze the association between LTPA/OPA and dementia and adjusted for self-reported age, socioeconomic factors, stress, and cardiovascular risk factors (smoking, alcohol, body mass index, and blood pressure). A higher level of LTPA was associated with a lower dementia risk among men, but we found no clear association among women. OPA and dementia were not associated among men, but occupationally active women who reported OPA in terms of walking, lifting, and heavy work had a higher risk of dementia than women with sedentary jobs. This study supported earlier findings of a protective effect of LTPA on dementia among men. Women in physically demanding jobs possibly have a higher risk of dementia, yet this finding warrants further investigation in future studies.

Replacement of sedentary behavior with various physical activities and the risk of all-cause and cause-specific mortality

BACKGROUND

Sedentary behavior (SB) has emerged as a significant health concern that deserves attention. This study aimed to examine the associations between prolonged sedentary behavior and the risk of all-cause and cause-specific mortality as well as to explore desirable alternatives to sitting in terms of physical activity (PA).

METHODS

Two prospective cohort investigations were conducted using the UK Biobank and NHANES datasets, with a total of 490,659 and 33,534 participants, respectively. Cox proportional hazards regression models were used to estimate the associations between SB and the risk of all-cause and cause-specific mortality due to cancer, cardiovascular disease (CVD), respiratory diseases, and digestive diseases. In addition, we employed isotemporal substitution models to examine the protective effect of replacing sitting with various forms of PA.

RESULTS

During the average follow-up times of 13.5 and 6.7 years, 36,109 and 3057 deaths were documented in the UK Biobank and NHANES, respectively. Both cohorts demonstrated that, compared with individuals sitting less than 5 h per day, individuals with longer periods of sitting had higher risks of all-cause and cause-specific mortality due to cancer, CVD, and respiratory diseases but not digestive diseases. Moreover, replacing SB per day with PA, even substituting 30 min of walking for pleasure, reduced the risk of all-cause mortality by 3.5% (hazard ratio [HR] 0.965, 95% confidence interval [CI] 0.954-0.977), whereas cause-specific mortality from cancer, CVD, and respiratory diseases was reduced by 1.6% (HR 0.984, 95% CI 0.968-1.000), 4.4% (HR 0.956, 95% CI 0.930-0.982), and 15.5% (HR 0.845, 95% CI 0.795-0.899), respectively. Furthermore, the protective effects of substitution became more pronounced as the intensity of exercise increased or the alternative duration was extended to 1 h.

CONCLUSIONS

SB was significantly correlated with substantially increased risks of all-cause mortality and cause-specific mortality from cancer, CVD, and respiratory diseases. However, substituting sitting with various forms of PA, even for short periods involving relatively light and relaxing physical activity, effectively reduced the risk of both overall and cause-specific mortality.

Development and validation of the eMCI-CHD tool: A multivariable prediction model for the risk of mild cognitive impairment in patients with coronary heart disease

OBJECTIVE

This study aimed to develop and validate an eMCI-CHD tool based on clinical data to predict mild cognitive impairment (MCI) risk in patients with coronary heart disease (CHD).

METHODS

This cross-sectional study prospectively collected data from 400 patients with coronary heart disease (aged 55-90 years, 62% men) from July 2022 to September 2023 and randomized (7:3 ratio) them into training and validation sets. After determining the modeling variables through least absolute shrinkage and selection operator regression analysis, four ML classifiers were developed: logistic regression, extreme gradient boosting (XGBoost), support vector machine, and random forest. The performance of the models was evaluated using area under the ROC curve, accuracy, sensitivity, specificity, and F1 score. Decision curve analysis was used to assess the clinical performance of the established models. The SHapley Additive exPlanations (SHAP) method was applied to determine the significance of the features, the predictive model was visualized with a nomogram, and an online web-based calculator for predicting CHD-MCI risk scores was developed.

RESULTS

Of 400 CHD patients (average age 70.86 ± 8.74 years), 220 (55%) had MCI. The XGBoost model demonstrated superior performance (AUC: 0.86, accuracy: 78.57%, sensitivity: 0.74, specificity: 0.84, F1: 0.79) and underwent validation. An online tool (https://mr.cscps.com.cn/mci/index.html) with seven predictive variables (APOE gene typing, age, education, TyG index, NT-proBNP, C-reactive protein, and occupation) assessed MCI risk in CHD patients.

CONCLUSION

This study highlights the potential for predicting MCI risk among CHD patients using an ML model-driven nomogram and risk scoring tool based on clinical data.

Trajectories of Occupational Cognitive Demands and Risk of Mild Cognitive Impairment and Dementia in Later Life: The HUNT4 70+ Study

BACKGROUND AND OBJECTIVES

The cognitive reserve hypothesis posits that cognitively stimulating work delays the onset of mild cognitive impairment (MCI) and dementia. However, the effect of occupational cognitive demands across midlife on the risk of these conditions is unclear.

METHODS

Using a cohort study design, we evaluated the association between registry-based trajectories of occupational cognitive demands from ages 30-65 years and clinically diagnosed MCI and dementia in participants in the HUNT4 70+ Study (2017-19). Group-based trajectory modeling identified trajectories of occupational cognitive demands, measured by the routine task intensity (RTI) index (lower RTI indicates more cognitively demanding occupation) from the Occupational Information Network. Multinomial regression was implemented to estimate the relative risk ratios (RRRs) of MCI and dementia, after adjusting for age, sex, education, income, baseline hypertension, obesity, diabetes, psychiatric impairment, hearing impairment, loneliness, smoking status, and physical inactivity assessed at HUNT1-2 in 1984-1986 and 1995-1997. To handle missing data, we used inverse probability weighting to account for nonparticipation in cognitive testing and multiple imputation.

RESULTS

Based on longitudinal RTI scores for 305 unique occupations, 4 RTI trajectory groups were identified (n = 7,003, 49.8% women, age range 69-104 years): low RTI (n = 1,431, 20.4%), intermediate-low RTI (n = 1,578, 22.5%), intermediate-high RTI (n = 2,601, 37.1%), and high RTI (n = 1,393, 19.9%). Participants in the high RTI group had a higher risk of MCI (RRR 1.74, 95% CI 1.41-2.14) and dementia (RRR 1.37, 95% CI 1.01-1.86), after adjusting for age, sex, and education compared with participants in the low RTI group. In a sensitivity analysis, controlling for income and baseline health-related factors, the point estimates were not appreciably changed (RRR 1.66, 95% CI 1.35-2.06 for MCI, and RRR 1.31, 95% CI 0.96-1.78 for dementia).

DISCUSSION

People with a history of cognitively stimulating occupations during their 30s, 40s, 50s, and 60s had a lower risk of MCI and dementia older than 70 years, highlighting the importance of occupational cognitive stimulation during midlife for maintaining cognitive function in old age. Further research is required to pinpoint the specific occupational cognitive demands that are most advantageous for maintaining later-life cognitive function.