Physical Activity and Alzheimer's Disease: A Narrative Review

Sex differences in the confounders influencing the relationships linking socioeconomic factors and cognitive performance with family history of Alzheimer's disease and related dementias

INTRODUCTION

Limited information is available regarding sex differences in the relationship of socioeconomic status and cognitive performance with Alzheimer's disease and related dementias (ADRD) family history.

METHODS

Leveraging the UK Biobank (N = 448,100) and All of Us Research Program (N = 240,319), we conducted observational and genetically informed analyses to test the sex-specific associations of socioeconomic factors and cognitive performance with ADRD and its family history.

RESULTS

Observational and genetically informed analyses highlighted that higher socioeconomic status and cognitive performance were associated with reduced ADRD and sibling-ADRD family history. Conversely, these were associated with increased parent-ADRD family history. Sex differences in these relationships were also identified. Additionally, although their sample size was limited, population minorities showed different patterns with respect to ADRD versus parent-ADRD family history.

DISCUSSION

This study highlights sex differences in the misestimated associations of ADRD family history that appear to be related to socioeconomic factors and cognitive performance.

HIGHLIGHTS

Alzheimer's disease family history is differently linked to socioeconomic factors. Observational and genetic analyses highlighted sex differences in these dynamics. Cause-effect relationships could contribute to biases in Alzheimer's disease assessment.

Cognitive gains and cortical thickness changes after 12 weeks of resistance training in older adults with low and high risk of mild cognitive impairment: Findings from a randomized controlled trial

BACKGROUND

In this randomized controlled trial, we assessed the neuroprotective effect of a 12-week resistance training (RT) program on executive control and cortical thickness of the prefrontal, temporal, parietal, and central cortex, regions prone to structural decline in individuals with mild cognitive impairment (MCI).

METHODS

Seventy older adults (aged 60-85 y old, 38 females and 32 males) were randomly allocated to a 12-week lower limb RT program or a waiting list control group. The Montreal Cognitive Assessment (MoCA) was used to stratify participants screened for high (< 26) or low (≥ 26) MCI risk. Cognitive measurements consisted of the two-choice reaction time, Go/No-go, mathematical processing, and memory search tests. Cortical thickness was estimated from 3D T1-weighted MR images.

RESULTS

Complete randomized controlled trial data was obtained from 50 individuals (24 with high MCI risk). Significant Group x Time interactions were found for response on the Go/No-go task and cortical thickness of the right parahippocampal gyrus [F ≥ 5.3, p ≤ 0.03; η2p ≥ 0.12]. An inspection of these observations revealed an increase in cortical thickness (+1.18 %) and a decrease in response time (-4.35 %) in individuals with high MCI risk allocated to the exercise group (both uncorrected p = 0.08). Decreased response time on the Go/No-go task was associated with increased cortical thickness in the right entorhinal gyrus (uncorrected p = 0.01).

CONCLUSIONS

Our study demonstrated that 12 weeks of RT intervention may effectively improve cognitive performance and slow neuronal loss in the hippocampal complex of older adults at high MCI risk. Findings support evidence for the neuroprotective effects of resistance training and its potential role in cognitive health.

The Multimodal MRI Features of Deteriorative MCI Patients-A 2-Year Follow-up Study

BACKGROUND

To explore the magnetic resonance imaging (MRI) features of the 2-year follow-up patients with deteriorative mild cognitive impairment (MCI).

METHODS

A number of 105 MCI-afflicted patients underwent multimodal MRI sequences in 2019 and 2021, respectively. The brain image was segmented into 116 regions, and the apparent diffusion coefficient (ADC) value, fractional anisotropy (FA) value, and cerebral blood flow (CBF) value of each brain region were extracted by the deep learning algorithm. They were divided into the deteriorative MCI group and the non-deteriorative MCI group according to the cognitive function 2 years later.

RESULTS

With the FA values analyzed, we found the characteristics in nine brain regions as follows: In both 2019 and 2021, the FA value was significantly lower in the deterioration group (DG) than in the non-deterioration group (NDG) (P < 0.001). In the DG, the FA value was significantly lower in 2021 than in 2019 (P < 0.001), while in the NDG, no significant difference was found in the FA value between 2019 and 2021 (P > 0.05). In terms of the ADC value, we found the characteristics in middle frontal gyrus-orbital part region as follows: In both 2019 and 2021, the ADC value was significantly higher in the DG than in the NDG (P < 0.001). In the DG, the ADC value was significantly higher in 2021 than in 2019 (P < 0.001).

CONCLUSIONS

The decrease of the FA value in nine brain regions and the increase of the ADC value in one brain region could be the warning characteristics of the deterioration of MCI.

The effect of the APOE4 genotype on physiological and cognitive health in randomised controlled trials with an exercise intervention: a systematic review and meta-analysis

BACKGROUND

Alzheimer's disease is caused by modifiable and non-modifiable risk factors. Randomised controlled trials have investigated whether the strongest genetic risk factor for Alzheimer's disease, APOE4, impacts the effectiveness of exercise on health. Systematic reviews are yet to evaluate the effect of exercise on physical and cognitive outcomes in APOE genotyped participants. A quality assessment of these randomised controlled trials is needed to understand the impact genotype has on the potential success of intervention. This systematic review aimed to determine if the APOE4 genotype influences the effectiveness of exercise-based randomised controlled trials.

METHOD

Searches on MEDLINE, EMBASE, and PsycINFO identified eligible exercise based randomised controlled trials incorporating participants with varied cognitive abilities. Quality assessments were conducted.

RESULTS

Nineteen studies met the inclusion criteria for systematic review, and 3 for the meta-analysis. Very low to moderate quality evidence showed that APOE4 carriers benefitted more than APOE4 non-carriers on cognitive (e.g. executive function, learning) and physical (e.g. relative telomere length) outcomes after exercise; and that APOE4 non-carriers benefited over carriers for physical (serum BDNF, gait speed) and cognitive (global cognition, verbal memory) markers. Very low quality evidence indicated that there was no evidence of difference between APOE4 carriers and non-carriers on physical function outcomes in meta-analysis. Several areas of study design and reporting, including maintenance of relative exercise intensity and complete statistical reporting, were identified as needing improvement.

DISCUSSION

This systematic review found very limited evidence to suggest that exercise interventions can benefit APOE4 carriers and non-carriers equally, though conclusions were limited by evidence quality. Further randomised controlled trials, stratifying participants by APOE status are required to better understand the relationship between APOE genotype and the effect of exercise on health-related outcomes.

TRIAL REGISTRATION

This review was registered with PROSPERO (CRD42023436842). Registered on June 16, 2023.

The Effect of Physical Exercise on Patients With Mild Cognitive Impairment: A Scoping Review

Mild cognitive impairment (MCI) is characterized by a noticeable decline in cognitive abilities that is not severe enough to significantly interfere with daily life or independent functioning. Recent research highlights the important role of exercise in managing and improving cognitive function in patients with MCI. This scoping review examines the benefits of different forms of exercise in improving cognitive function. Recommendations for exercise, including frequency, consistency, and individualized programs, are discussed in this review, with an emphasis on the importance of safety and regular monitoring. The integration of physical and cognitive training is also suggested to maximize benefits. Regular physical exercise is a promising intervention for mitigating cognitive decline and improving the overall quality of life in patients with MCI.

Sex differences in the associations of socioeconomic factors and cognitive performance with family history of Alzheimer's disease

INTRODUCTION

While higher socioeconomic factors (SEF) and cognitive performance (CP) have been associated with reduced Alzheimer's disease (AD) risk, recent evidence highlighted that these factors may have opposite effects on family history of AD (FHAD).

METHODS

Leveraging data from the UK Biobank (N=448,100) and the All of Us Research Program (N=240,319), we applied generalized linear regression models, polygenic risk scoring (PRS), and one-sample Mendelian randomization (MR) to test the sex-specific SEF and CP associations with AD and FHAD.

RESULTS

Observational and genetically informed analyses highlighted that higher SEF and CP were associated with reduced AD and sibling-FHAD, while these factors were associated with increased parent-FHAD. We also observed that population minorities may present different patterns with respect to sibling-FHAD vs. parent-FHAD. Sex differences in FHAD associations were identified in ancestry-specific and SEF PRS and MR results.

DISCUSSION

This study contributes to understanding the sex-specific relationships linking SEF and CP to FHAD, highlighting the potential role of reporting, recall, and surviving-related dynamics.

Physical Activity Inclusion in Dementia-Friendly Communities: A Mixed Methods Study

Dementia-friendly communities (DFCs) are a policy-endorsed approach to community engagement in England that promotes social inclusion to enable people affected by dementia to live well. Research suggests that physical activity is beneficial in encouraging social connection and improving health. A mixed method sequential study design in England involving a national survey (n = 31) and semistructured interviews (n = 65) in three DFCs was carried out. The aim was to understand how DFCs enable people affected by dementia to participate in physical activities. An evaluation framework for DFCs was used to organize and interpret the data, and analysis was informed by the inclusive (social) citizen lens. Findings showed that DFCs offered a range of adapted dementia-inclusive and dementia-specific activities; however, people were not routinely offered information at time of diagnosis. Local authorities (councils) were key to enable access to information and infrastructure change to support sustainable inclusion within their local community.

A Dual-Task Paradigm Combining Physical and Cognitive Training in Mice: Application to Aging

Physical Activity (PA) is often associated with better overall health status, especially in older adults. Numerous pieces of evidence indicate that PA would be more beneficial when applied in conjunction with Cognitive Training (CT) either simultaneously (i.e., in Dual-Task [DT]) or sequentially. Nonetheless, the underlying mechanisms of such benefits remain elusive. To help delve deeper into their understanding, we developed a cognitive-motor DT paradigm in young adult mice and subsequently tested its effect in old age. Three groups of young adults C57BL/6J mice (3.5 months of age; n=10/group) were required. They were given cognitive tasks, either alone (Control) or in combination with PA which was administered either sequentially (SeqT group) or simultaneously (DT group). Mice were trained in a touchscreen chamber: first on a Visual Discrimination (VD) learning task, then on its Reversal (RVD) which assesses cognitive flexibility alongside procedural learning. PA was given through a homemade treadmill, designed to fit in the touchscreen chambers and set at 9 m/min. Fourteen months later, we further evaluated the effects of PA administered in both DT and SeqT groups, on the performance of the now 19-month-old mice. When compared to SeqT and control groups, DT mice significantly displayed better procedural learning in both VD and RVD tasks as young adults. In the RVD task, this enhanced performance was associated with both poorer inhibition and motor performance. Finally, in 19-month-old mice, both DT and SeqT mice displayed better motor and cognitive performances than control mice. This new cognitive-motor DT paradigm in mice yields an interesting framework that should be useful for adapting DT training in aging, including providing knowledge on the neurobiological correlates, to get the most out of its benefits.

Assessing the Global, Regional, and National Impact of High Body Mass Index on Alzheimer's Disease and Other Dementias Between 1990 and 2019

BACKGROUND

Obesity significantly increases Alzheimer's disease (AD) and dementia risk. Understanding the link between a high body mass index (BMI) and these conditions is crucial for effective management and prevention.

OBJECTIVE

We aimed to estimate the burden of AD and other dementias attributed to high BMI from 1990 to 2019 based on sex, age, and socio-demographic indicators (SDI) at global, regional, and national levels.

METHODS

We collected data on deaths, disability-adjusted life years (DALYs), age-standardized mortality rates (ASMR), and age-standardized DALY rates (ASDR) from the 2019 Global Burden of Disease study for AD and dementia attributed to high BMI. We explored the correlation between SDI levels and ASDR.

RESULTS

In 2019, there were 198,476.2 deaths (95% UI: 32,695.4-593,366.4) and 3,159,912.4 DALYs (848,330.5-8,042,531) attributed to high BMI. Numbers of deaths, DALYs, ASMR, and ASDR increased since 1990. Females had higher deaths, ASMR, and ASDR than males. Mortality and DALYs rates increased with age. ASMR and ASDR increased across five SDI levels, with the highest rise in Low-middle SDI. High-income North America had the most deaths [30,993.9 (5,101.7-89,912.9)], while North Africa and the Middle East had the highest ASMR [4.61 (0.79-13.64)] and ASDR [72.56 (20.98-181.16)] in 2019.

CONCLUSIONS

The burden of AD and other dementias attributed to high BMI increased since 1990 globally and is still heaviest in developed regions. Females accounted predominantly for the burden than males. Timely measures are needed to against high BMI.

Is Dance Closer to Physical Activity or Spirituality? A Philosophical Exploration

Dancing is inevitably associated with kinesthetics of the body, including movements, gestures, poses, jumps, turnings, transferring body weight, etcetera. Thus, dance is a manifestation of an amateur or the skilled behavior of a fully trained athletic performance. At the same time, dance is accompanied by emotions as an effect of expression, narration of choreography. Dance is also pre-planned and designed to produce numerous styles and techniques. It is a unique type of improvisation. However, in certain situations, styles and techniques that will be discussed below, the dancing body can bring the dancer closer to his/her emotionality and even spirituality. Thus, the aim of this philosophical exploration is to analyze the impact of spirituality on dance performance.

Modifying effects of race and ethnicity and APOE on the association of physical activity with risk of Alzheimer's disease and related dementias

INTRODUCTION

We investigated whether the protective association of physical activity with risk of Alzheimer's disease and related dementias (ADRD) has genetic or behavioral variations.

METHODS

In the Multiethnic Cohort, we analyzed moderate or vigorous physical activity (MVPA) reported at ages 45 to 75 among 88,047 participants in relation to 13,039 incident diagnoses of late-onset ADRD identified in Medicare claims (1999 to 2014), by five racial and ethnic groups, hours sitting, and in a subset (16%), apolipoprotein E (APOE) genotype.

RESULTS

MVPA was inversely associated with ADRD (hazard ratio for ≥14 vs <2.5 hours/week: 0.83, 95% confidence interval [CI]: 0.76 to 0.90 in men; 0.88, 5% CI: 0.81 to 0.95 in women). The association was inverse in all racial and ethnic groups except Black participants (P-heterogeneity = 0.52), but stronger in individuals with lower levels of sitting duration or those who do not carry the APOE e4 risk allele.

DISCUSSION

The different effects of physical activity by sitting duration and APOE genotype warrant further research.

Research trends and hotspots of exercise for Alzheimer’s disease: A bibliometric analysis

Objective

Alzheimer’s disease (AD) is a socially significant neurodegenerative disorder among the elderly worldwide. An increasing number of studies have revealed that as a non-pharmacological intervention, exercise can prevent and treat AD. However, information regarding the research status of this field remains minimal. Therefore, this study aimed to analyze trends and topics in exercise and AD research by using a bibliometric method.

Methods

We systematically searched the Web of Science Core Collection for published papers on exercise and AD. The retrieved data regarding institutions, journals, countries, authors, journal distribution, and keywords were analyzed using CiteSpace software. Meanwhile, the co-occurrence of keywords was constructed.

Results

A total of 1,104 papers were ultimately included in accordance with our specified inclusion criteria. The data showed that the number of published papers on exercise and AD is increasing each year, with papers published in 64 countries/regions and 396 academic journals. The Journal of Alzheimer’s Disease published the most papers (73 publications). Journals are concentrated in the fields of neuroscience and geriatrics gerontology. The University of Kansas and the United States are the major institution and country, respectively. The cited keywords show that oxidative stress, amyloid beta, and physical exercise are the research hotspots in recent years. After analysis, the neuroprotective effect of exercise was identified as the development trend in this field.

Conclusions

Based on a bibliometric analysis, the number of publications on exercise and AD has been increasing rapidly, especially in the past 10 years. “Amyloid beta,” “oxidative stress,” and “exercise program” trigger the most interest among researchers in this field. The study of exercise program and mechanism of exercise in AD is still the focus of future research.

Factors associated with social participation in Brazilian older adults with Alzheimer's disease: A correlational, cross-sectional study

The occurrence of Alzheimer's disease (AD) can exert a negative impact in social participation in affected older adults. The purpose of this study was to investigate whether social participation in older adults with AD is associated with disease stage and cognitive function as well as the quality of life and depressive symptoms in their caregivers. A correlational, cross-sectional study was conducted in 40 older adults with AD (28 women and 12 men) and 40 caregivers (30 women and 10 men). Social participation was assessed using the 'social participation' domain of the Activities of Daily Living Questionnaire. Disease stage was determined using the Clinical Dementia Rating scale and cognitive function was assessed using Addenbrooke's Cognitive Examination. Quality of life and depressive symptoms in the caregivers were evaluated using the Quality of Life Assessment Scale on Alzheimer's Disease and Beck Depression Inventory respectively. The older adults with AD had a mean percentage of 59.4% on the social participation domain and a mean score of 49.0 for cognitive function. The caregivers had mean scores of 39.1 for quality of life and 9.9 for depressive symptoms. The stepwise backward multiple linear regression model indicated that the predictors analysed together explained 48% of the variability in social participation among older adults with AD. Therefore, lower social participation among older adults with AD is associated with more advanced stages of the disease and cognitive decline in these individuals as well as a lower perception of quality of life and greater levels of depressive symptoms in their caregivers.

Scalar on time-by-distribution regression and its application for modelling associations between daily-living physical activity and cognitive functions in Alzheimer's Disease

Wearable data is a rich source of information that can provide a deeper understanding of links between human behaviors and human health. Existing modelling approaches use wearable data summarized at subject level via scalar summaries in regression, temporal (time-of-day) curves in functional data analysis (FDA), and distributions in distributional data analysis (DDA). We propose to capture temporally local distributional information in wearable data using subject-specific time-by-distribution (TD) data objects. Specifically, we develop scalar on time-by-distribution regression (SOTDR) to model associations between scalar response of interest such as health outcomes or disease status and TD predictors. Additionally, we show that TD data objects can be parsimoniously represented via a collection of time-varying L-moments that capture distributional changes over the time-of-day. The proposed method is applied to the accelerometry study of mild Alzheimer's disease (AD). We found that mild AD is significantly associated with reduced upper quantile levels of physical activity, particularly during morning hours. In-sample cross validation demonstrated that TD predictors attain much stronger associations with clinical cognitive scales of attention, verbal memory, and executive function when compared to predictors summarized via scalar total activity counts, temporal functional curves, and quantile functions. Taken together, the present results suggest that SOTDR analysis provides novel insights into cognitive function and AD.

Effects of Exercise in the Treatment of Alzheimer's Disease: An Umbrella Review of Systematic Reviews and Meta-Analyses

The authors aimed to provide an overview of the evidence on the effects of exercise in people with Alzheimer's disease through a comprehensive review of the existing systematic reviews and meta-analyses. A literature search was performed in CINAHL, Cochrane Library, EMBASE, PubMed, SPORTDiscus, Scopus, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The AMSTAR-2-Tool was used for the quality assessment. Twenty-three reviews fulfilled the criteria. Most of the reviews investigated the effects of aerobic exercise on Alzheimer's disease symptoms. The largest effects of exercise were seen in terms of improved cognition by multiple exercises. The majority of the reviews were rated as being of moderate quality and none were classified as having high quality. Exercise is an effective way to treat Alzheimer's disease symptoms and has a low incidence of related adverse events. As most reviews were evaluated as low-moderate quality, caution is needed in the interpretation of the results.

Exercise and Interorgan Communication: Short-Term Exercise Training Blunts Differences in Consecutive Daily Urine 1H-NMR Metabolomic Signatures between Physically Active and Inactive Individuals

Physical inactivity is a worldwide health problem, an important risk for global mortality and is associated with chronic noncommunicable diseases. The aim of this study was to explore the differences in systemic urine ¹H-NMR metabolomes between physically active and inactive healthy young males enrolled in the X-Adapt project in response to controlled exercise (before and after the 3-day exercise testing and 10-day training protocol) in normoxic (21% O₂), normobaric (~1000 hPa) and normal-temperature (23 °C) conditions at 1 h of 50% maximal pedaling power output (W_peak) per day. Interrogation of the exercise database established from past X-Adapt results showed that significant multivariate differences existed in physiological traits between trained and untrained groups before and after training sessions and were mirrored in significant differences in urine pH, salinity, total dissolved solids and conductivity. Cholate, tartrate, cadaverine, lysine and N6-acetyllisine were the most important metabolites distinguishing trained and untrained groups. The relatively little effort of 1 h 50% W_peak per day invested by the untrained effectively modified their resting urine metabolome into one indistinguishable from the trained group, which hence provides a good basis for the planning of future recommendations for health maintenance in adults, irrespective of the starting fitness value. Finally, the 3-day sessions of morning urine samples represent a good candidate biological matrix for future delineations of active and inactive lifestyles detecting differences unobservable by single-day sampling due to day-to-day variability.

Recommendations to Enhance Parental Involvement and Adolescent Participation in Physical Activity

Background: Adolescents are influenced by external factors which may impact their level of physical activity. Parents require specific strategies to become involved and to increase physical activity participation in adolescence. Objective: Thus, the current study aimed to design recommendations to increase physical activity participation and parental involvement. Methods: The current study forms part of a broader mixed-method study in which the results of the phases and stages of the pre-studies informed the current study. Thus, the current study uses an agreement workshop to develop recommendations with stakeholder and expert input in two rounds. Participants were invited to participate in the current study n = 100, and n = 65 participated in round one. Round two consisted of n = 20 experts invited to an agreement workshop, with n = 11 attending and making an input on the final recommendations. Therefore, experts and parents in the field of parenting, physical activity, and physical education, were invited to participate in the study rounds. After each round, the responses from the panellists were collated, interpreted, and developed into a framework for recommendations using thematic analysis. Themes were generated and refined using an agreement format. Results: After results from the stages and phases were consolidated and refined, six themes and 51 sub-themes were identified in a framework for recommendations. The framework was further refined using expert input and the final recommendations were derived using an agreement or agreement. Thus, with input from experts input through the agreement workshop, the findings were discussed, refined, and drafted into recommendations. Agreement and agreement were achieved on six broad recommendations and fifty-one sub-themes. The final recommendations were presented in the current study to increase parental involvement and physical activity in adolescents. Discussion: Recommendations and physical activity resources were developed and are presented as a form of support to parents and adolescents. The recommendations are intended as a source of unbiased information for parents to become more involved and for adolescents to increase physical activity participation.

The Effects of Physical Running on Dendritic Spines and Amyloid-beta Pathology in 3xTg-AD Male Mice

Memory loss is the key symptom of Alzheimer's disease (AD). As successful drug treatments have not yet been identified, non-pharmaceutical interventions such as physical exercise and training have been employed to improve the memory function of people with dementia. We investigated the effect of prolonged physical running on hippocampal-dependent spatial memory and its underlying mechanisms using a well-established rodent model of AD. 3xTg-AD transgenic mice and non-transgenic mice were subjected to voluntary wheel running for 5 months (1 hour per day, 5 days per week), followed by spatial memory testing. After the behavioral testing, dendritic spines, synapses, and synaptic proteins as well as amyloid-beta (Aβ) pathology were analyzed in the dorsal hippocampi. Running improved hippocampal-dependent spatial memory in 3xTg-AD mice. This running strategy prevented both thin and mushroom-type spines on CA1 pyramidal cells in 3xTg-AD mice, whereas the effects of running in non-transgenic mice were limited to thin spines. The enormous effects of running on spines were accompanied by an increased number of synapses and upregulated expression of synaptic proteins. Notably, running downregulated the processing of amyloid precursor protein, decreasing intracellular APP expression and extracellular Aβ accumulation, and spatial memory performance correlated with levels of Aβ peptides Aβ_1-40 and Aβ_1-42. These data suggest that prolonged running may improve memory in preclinical AD via slowing down the amyloid pathology and preventing the loss of synaptic contacts.

Dance and Music for Improving Health among Patients with Breast Cancer and Parkinson’s Disease: A Narrative Review

Although a longer life may bring new opportunities for older people and society, advancing age is a leading risk factor for developing several chronic diseases, consequently limiting the health span. During the ageing process, changes in the activity of several endocrine glands may occur, leading to different clinical conditions. Being physically active becomes fundamental for healthy ageing. Despite regular physical activity being shown to have many health benefits, patients with cancer and neurodegenerative diseases remain physically inactive. Over the past two decades, there has been a major increase in arts engagement (e.g., dance and music) on health and well-being in both clinical and non-clinical contexts. Dance and music have been shown to induce positive effects on hormonal glands, patients’ sociality, and self-confidence. Therefore, this review aims to highlight evidence regarding the effects of music and dance on hormonal responses and as preventive and compliance tools for heathy ageing in breast cancer and Parkinson’s disease patients.

Inflammatory Bowel Disease and Patients With Mental Disorders: What Do We Know?

Inflammatory bowel disease (IBD) is a multisystemic disease with a wide range of extraintestinal manifestations in both ulcerative colitis and Crohn’s disease, while increasing evidence supports the interaction between gut and central nervous system, described as “gut-brain axis”. According to epidemiological studies, it seems that patients with IBD present more frequently with impaired mental status compared to the general population, leading to diagnostic and management problems in this group of patients. The association between IBD and mental disorders, such as dementia and autism spectrum disorders, has not been fully clarified; genetic factors and the gut-brain axis seem to be involved. The purpose of this review is to present and analyze the epidemiological data about this issue, describe the possible pathogenetic mechanisms and discuss some considerations about the management of patients with IBD and impaired mental status.

Neuroplastic Effect of Exercise Through Astrocytes Activation and Cellular Crosstalk

Physical exercise is an effective therapy for neurorehabilitation. Exercise has been shown to induce remodeling and proliferation of astrocyte. Astrocytes potentially affect the recruitment and function of neurons; they could intensify responses of neurons and bring more neurons for the process of neuroplasticity. Interactions between astrocytes, microglia and neurons modulate neuroplasticity and, subsequently, neural circuit function. These cellular interactions promote the number and function of synapses, neurogenesis, and cerebrovascular remodeling. However, the roles and crosstalk of astrocytes with neurons and microglia and any subsequent neuroplastic effects have not been studied extensively in exercise-induced settings. This article discusses the impact of physical exercise on astrocyte proliferation and highlights the interplay between astrocytes, microglia and neurons. The crosstalk between these cells may enhance neuroplasticity, leading to the neuroplastic effects of exercise.

Running exercise protects spinophilin-immunoreactive puncta and neurons in the medial prefrontal cortex of APP/PS1 transgenic mice

The medial prefrontal cortex (mPFC) is thought to be closely associated with emotional processes, decision making, and memory. Previous studies have identified the prefrontal cortex as one of the most vulnerable brain regions in Alzheimer's disease (AD). Running exercise has widely been recognized as a simple and effective method of physical activity that enhances brain function and slows the progression of AD. However, the effect of exercise on the mPFC of AD is unclear. To address these issues, we investigated the effects of 4 months of exercise on the numbers of spinophilin-immunoreactive puncta and neurons in the mPFC of 12-month-old APPswe/PSEN1dE9 (APP/PS1) transgenic AD model mice using stereological methods. The spatial learning and memory abilities of mice were tested using the Morris water maze. Four months of running exercise delayed declines in spatial learning and memory abilities. The stereological results showed significantly lower numbers of spinophilin-immunoreactive puncta and neurons in the mPFC of APP/PS1 mice than in the wild-type control group. The numbers of spinophilin-immunoreactive puncta and neurons in the mPFC of running APP/PS1 mice were significantly greater than those in the APP/PS1 control mice. In addition, running-induced improvements in spatial learning and memory were significantly associated with running-induced increases in spinophilin-immunoreactive puncta and neurons numbers in the mPFC. Running exercise could delay the loss of spinophilin-immunoreactive puncta and neurons in the mPFC of APP/PS1 mice. This finding might provide an important structural basis for exercise-induced improvements in the spatial learning and memory abilities of individuals with AD.

Risk Assessment During Longitudinal Progression of Cognition in Older Adults: A Community-based Bayesian Networks Model

BACKGROUND

Cognitive dysfunction, particularly in Alzheimer's disease (AD), seriously affects the health and quality of life of older adults. Early detection can prevent and slow cognitive decline.

OBJECTIVE

This study aimed at evaluating the role of socio-demographic variables, lifestyle, and physical characteristics in cognitive decline during AD progression and analyzing the probable causes and predicting stages of the disease.

METHODS

By analyzing data of 301 subjects comprising normal elderly and patients with mild cognitive impairment (MCI) or AD from six communities in Taiyuan, China, we identified the influencing factors during AD progression by a Logistic Regression model (LR) and then assessed the associations between variables and cognition using a Bayesian Networks (BNs) model.

RESULTS

The LR revealed that age, sex, family status, education, income, character, depression, hypertension, disease history, physical exercise, reading, drinking, and job status were significantly associated with cognitive decline. The BNs model revealed that hypertension, education, job status, and depression affected cognitive status directly, while character, exercise, sex, reading, income, and family status had intermediate effects. Furthermore, we predicted probable cognitive stages of AD and analyzed probable causes of these stages using a model of causal and diagnostic reasoning.

CONCLUSION

The BNs model lays the foundation for causal analysis and causal inference of cognitive dysfunction, and the prediction model of cognition in older adults may help the development of strategies to control modifiable risk factors for early intervention in AD.

Lifestyle-dependent microglial plasticity: training the brain guardians

Lifestyle is one of the most powerful instruments shaping mankind; the lifestyle includes many aspects of interactions with the environment, from nourishment and education to physical activity and quality of sleep. All these factors taken in complex affect neuroplasticity and define brain performance and cognitive longevity. In particular, physical exercise, exposure to enriched environment and dieting act through complex modifications of microglial cells, which change their phenotype and modulate their functional activity thus translating lifestyle events into remodelling of brain homoeostasis and reshaping neural networks ultimately enhancing neuroprotection and cognitive longevity.

Modifiable Risk Factors in Alzheimer Disease and Related Dementias: A Review

PURPOSE

Although Alzheimer disease and related dementias (ADRDs) have long been considered nonpreventable and even an inevitable consequence of aging, recent findings from longitudinal studies indicate a downtrend in age-adjusted incidence and prevalence of ADRDs in Western countries. This remarkable trend might be the result of improved management of so-called modifiable risk factors. The aim of this review is to present evidence of modifiable factors of ADRDs in a life-course approach.

METHODS

A PubMed database search was conducted between November and December 2020 to identify relevant studies evaluating the role of modifiable risk factors in the development of ADRDs. Key words (Alzheimer's disease and modifiable risk factors) were used and specific inclusion and exclusion criteria applied.

FINDINGS

This review identifies modifiable factors for ADRDs divided into early-life, middle-life, and late-life risk factors, depending on the available window of preventive action. According to life course exposure, factors can be protective or deleterious for ADRDs that participate in the underlying pathophysiologic complexity of these diseases as well as the complexity for public health measures implementations.

IMPLICATIONS

The available evidence derived from epidemiologic, preclinical, interventional studies suggest that modifiable risk factors for ADRDs offer opportunities for therapeutic and preventive actions.

Body adaptation to Dance: A Gerontological Perspective

A number of studies have investigated the effectiveness of dance in older adults in the context of healthy aging. Analysing results across studies is important to understand whether dance in older adults is an effective adjunctive intervention for the healthy aging. To summarize the current research results about the effectiveness of dance in older adults in the context of healthy aging, and to identify key areas for future research. The search was conducted in Web of Science, PubMed and Google Scholar databases, using the following search string and Boolean logic (‘AND’, ‘OR’) locating studies published between database inception and September 2018: Dance OR contemporary dance OR ballroom dance OR Latin dance OR standard dance OR hip-hop dance OR tango AND Cardiovascular OR circulation AND Emotion OR well-being OR blood pressure OR disease OR thrombosis OR vascular OR glucose OR blood OR cardiac OR mental OR heart rate. Two reviewers independently extracted studies data. Eight suitable publications were included. The results showed that dance promote improvements in cognitive parameters when compared to other types of exercise or no-exercise. Significant effects were found on some physiological parameters, even after a short intervention period. Dance proved to be able to assist older adults in the context of healthy aging. The improvements in the cognitive, physiological and motor control parameters are very relevant for this population, due to the impact in a better quality of life.

Key Signaling Pathways in Aging and Potential Interventions for Healthy Aging

Aging is a fundamental biological process accompanied by a general decline in tissue function. Indeed, as the lifespan increases, age-related dysfunction, such as cognitive impairment or dementia, will become a growing public health issue. Aging is also a great risk factor for many age-related diseases. Nowadays, people want not only to live longer but also healthier. Therefore, there is a critical need in understanding the underlying cellular and molecular mechanisms regulating aging that will allow us to modify the aging process for healthy aging and alleviate age-related disease. Here, we reviewed the recent breakthroughs in the mechanistic understanding of biological aging, focusing on the adenosine monophosphate-activated kinase (AMPK), Sirtuin 1 (SIRT1) and mammalian target of rapamycin (mTOR) pathways, which are currently considered critical for aging. We also discussed how these proteins and pathways may potentially interact with each other to regulate aging. We further described how the knowledge of these pathways may lead to new interventions for antiaging and against age-related disease.

Plasma hydrogen sulfide: A biomarker of Alzheimer's disease and related dementias

While heart disease remains a common cause of mortality, cerebrovascular disease also increases with age, and has been implicated in Alzheimer's disease and related dementias (ADRD). We have described hydrogen sulfide (H₂S), a signaling molecule important in vascular homeostasis, as a biomarker of cardiovascular disease. We hypothesize that plasma H₂S and its metabolites also relate to vascular and cognitive dysfunction in ADRD. We used analytical biochemical methods to measure plasma H₂S metabolites and MRI to evaluate indicators of microvascular disease in ADRD. Levels of total H₂S and specific metabolites were increased in ADRD versus controls. Cognition and microvascular disease indices were correlated with H₂S levels. Total plasma sulfide was the strongest indicator of ADRD, and partially drove the relationship between cognitive dysfunction and white matter lesion volume, an indicator of microvascular disease. Our findings show that H₂S is dysregulated in dementia, providing a potential biomarker for diagnosis and intervention.

Apolipoprotein E Polymorphism and Oxidative Stress in Human Peripheral Blood Cells: Can Physical Activity Reactivate the Proteasome System through Epigenetic Mechanisms?

Alzheimer's disease (AD) is characterized by proteasome activity impairment, oxidative stress, and epigenetic changes, resulting in β-amyloid (Aβ) production/degradation imbalance. Apolipoprotein E (ApoE) is implicated in Aβ clearance, and particularly, the ApoE ε4 isoform predisposes to AD development. Regular physical activity is known to reduce AD progression. However, the impact of ApoE polymorphism and physical exercise on Aβ production and proteasome system activity has never been investigated in human peripheral blood cells, particularly in erythrocytes, an emerging peripheral model used to study biochemical alteration. Therefore, the influence of ApoE polymorphism on the antioxidant defences, amyloid accumulation, and proteasome activity was here evaluated in human peripheral blood cells depending on physical activity, to assess putative peripheral biomarkers for AD and candidate targets that could be modulated by lifestyle. Healthy subjects were enrolled and classified based on the ApoE polymorphism (by the restriction fragment length polymorphism technique) and physical activity level (Borg scale) and grouped into ApoE ε4/non-ε4 carriers and active/non-active subjects. The plasma antioxidant capability (AOC), the erythrocyte Aβ production/accumulation, and the nuclear factor erythroid 2-related factor 2 (Nrf2) mediated proteasome functionality were evaluated in all groups by the chromatographic and immunoenzymatic assay, respectively. Moreover, epigenetic mechanisms were investigated considering the expression of histone deacetylase 6, employing a competitive ELISA, and the modulation of two key miRNAs (miR-153-3p and miR-195-5p), through the miRNeasy Serum/Plasma Mini Kit. ApoE ε4 subjects showed a reduction in plasma AOC and an increase in the Nrf2 blocker, miR-153-3p, contributing to an enhancement of the erythrocyte concentration of Aβ. Physical exercise increased plasma AOC and reduced the amount of Aβ and its precursor, involving a reduced miR-153-3p expression and a miR-195-5p enhancement. Our data highlight the impact of the ApoE genotype on the amyloidogenic pathway and the proteasome system, suggesting the positive impact of physical exercise, also through epigenetic mechanisms.

Effects of Physical Activity on Brain Energy Biomarkers in Alzheimer's Diseases

The prevalence of dementia has substantially increased worldwide. Currently, there is no cure for dementia or Alzheimer’s disease (AD), and care for affected patients is financially and psychologically costly. Of late, more attention has been given to preventive interventions—in particular, physical activity/exercise. In this review, examine the risk factors associated with AD and the effects physical activity may play in the prevention of the degenerative process of this disease, loss of memory and cognitive performance in the elderly. To date, research has shown that physical activity, especially aerobic exercise, has a protective effect on cognitive function and memory in the elderly and Alzheimer’s patients. In comparison with aerobic exercise, several strength training studies have also shown positive effects, and the rare studies that compare the two different modalities show no difference.