Exercise interventions in Alzheimer's disease: A systematic review and meta-analysis of randomized controlled trials

Comparing the impact of various exercise modalities on old adults with Alzheimer's disease: A Bayesian network meta-analysis

BACKGROUND AND PURPOSE

The global prevalence of Alzheimer's disease (AD) in the elderly is rising, and exercise is increasingly used as a non-pharmacological intervention. However, the most effective exercise modality for improving quality of life, alleviating depression, and reducing neuropsychiatric symptoms in AD patients remains unclear. This study aims to identify the optimal exercise modality for addressing these symptoms through a network meta-analysis.

METHODS

As of November 2024, we conducted a comprehensive search across six databases: PubMed, Embase, Web of Science, the Cochrane Central Register of Controlled Trials, CINAHL, and PsycINFO. This study included only randomized controlled trials (RCTs), with study durations ranging from 2 to 24 weeks, primarily set in clinical or community environments. Following the PRISMA-NMA guidelines, we conducted statistical analysis using the "gemtc" package in R and assessed evidence quality via the CINeMA online platform.

RESULTS

A network meta-analysis of 29 RCTs with 1507 participants showed that for global cognition, Aerobic exercise (AE) [MD = 2.83, 95 % CI (0.66, 4.85)] ranked first with 79.5 % probability; for quality of daily life, Resistance Training (RT) [SMD = 0.96, 95 % CI (-0.14, 2.07)] ranked first with 83.7 %; for depression, Physical Activity Program (PAP) [SMD = -3.76, 95 % CI (-7.06, -0.47)] ranked first with 96.0 %; and for neuropsychiatric inventory outcomes, AE [SMD = -2.35, 95 % CI (-5.95, 1.06)] ranked first with 71.1 %.

CONCLUSIONS

Based on the findings from retrospective studies, aerobic exercise may be an effective intervention for improving overall cognition and quality of life in individuals aged 60 and above with Alzheimer's disease.

Aerobic exercise improves astrocyte mitochondrial quality and transfer to neurons in a mouse model of Alzheimer's disease

Mitochondrial dysfunction is a well-established hallmark of Alzheimer's disease (AD). Despite recent documentation of transcellular mitochondrial transfer, its role in the pathogenesis of AD remains unclear. In this study, we report an impairment of mitochondrial quality within the astrocytes and neurons of adult 5 × FAD mice. Following treatment with mitochondria isolated from aged astrocytes induced by exposure to amyloid protein or extended cultivation, cultured neurons exhibited an excessive generation of reactive oxygen species and underwent neurite atrophy. Notably, aerobic exercise enhanced mitochondrial quality by upregulating CD38 within hippocampal astrocytes of 5 × FAD mice. Conversely, the knockdown of CD38 diminished astrocytic-neuronal mitochondrial transfer, thereby abolishing the ameliorative effects of aerobic exercise on neuronal oxidative stress, β-amyloid plaque deposition, and cognitive dysfunction in 5 × FAD mice. These findings unveil an unexpected mechanism through which aerobic exercise facilitates the transference of healthy mitochondria from astrocytes to neurons, thus countering the AD-like progression.

Disentangling preventive effects of differential exercise types on tension-type headache: a component network meta-analysis of randomized controlled trials

BACKGROUND

The effectiveness of exercise for tension-type headache (TTH) is unclear because of the complexity of exercise regimens-usually the combination of different types of exercise. We aimed to estimate the effectiveness of exercise for TTH and to test the incremental effect of each type of exercise by component network meta-analysis (CNMA).

METHODS

We searched Ovid Medline, Embase, and the Cochrane Library from database inception to 25 December 2023, and a supplementary search was conducted on 10 February 2025. We included randomized controlled trials of exercise, including aerobic, resistance, and stretching exercise, in adults with TTH. The primary outcome was headache frequency, and secondary outcomes were headache intensity and medication use.

RESULTS

Twelve trials with 759 participants were included. There were no significant differences between exercise and usual care in reducing headache frequency at the end of treatment with very low certainty evidence (mean difference [MD] -2.30, 95% [confidence interval] CI -8.86 to 4.26), while CNMA suggested that resistance exercise significantly reduced headache frequency (incremental mean difference [iMD] -6.00, 95% CI -9.10 to -2.90) and stretching exercise increased headache frequency (iMD 4.60, 95% CI 1.20 to 8.00). Exercise was better than usual care in reducing headache intensity (MD -2.29, 95% CI -3.23 to -1.34); the CNMA suggested that no single type of exercise had the greatest effect.

CONCLUSION

Resistance exercise could be considered an effective and accessible treatment for patients with TTH. But our study was limited by heterogeneity and inconsistency of results, and more studies are warranted.

Intervention points for the role of physical activity in prevention and treatment of Alzheimer's disease

Alzheimer's disease (AD) is a growing global health challenge with limited pharmacological treatments. Epidemiological studies link regular physical activity with a lower risk of AD and cognitive decline in general, whereas randomized controlled trials show that aerobic exercise slows disease progression and improves cognitive function. However the underlying mechanisms remain incompletely understood. In this review we discuss five likely intervention points through which physical activity may influence AD progression and pathology: (1) reducing neuroinflammation and amyloid beta (Aβ) aggregation, (2) enhancing clearance of Aβ aggregates, (3) increasing neuronal resilience, (4) promoting hippocampal neurogenesis and (5) strengthening cognitive reserve. Understanding which of these mechanistic links are most likely to drive the AD-protective effects of exercise could help refine lifestyle-based interventions to complement pharmacological treatments and inform future prevention strategies.

Mapping the scientific research on exercise therapy for Alzheimer's disease: a scientometric study of hotspots and emerging trends

Background

Alzheimer's disease (AD) is the most common form of dementia globally, placing a substantial economic burden on patients and society. Exercise serves as an adjuvant therapy for AD with a low incidence of related adverse events. As a non-pharmacological intervention, it has demonstrated significant potential in the therapy of AD.

Objective

This study examines the key hotspots and emerging trends in exercise therapy for AD, offering valuable insights for researchers engaged in future research in this field.

Methods

The Web of Science Core Collection database was utilized to search for literature on exercise therapy for AD from January 1, 2000, to November 1, 2024, with 1,372 relevant articles being identified. And CiteSpace 6.2.R4 and VOSviewer were used to evaluate the bibliometric indicators.

Results

Since 2000, the number of publications in the field of exercise therapy for AD has been increasing. In addition to the well-known areas of research, such as the impact of exercise on cognitive function, the combination of exercise and medication therapy, the effects of exercise on specific symptoms, and the exercise with music therapy, the field may also focus on more novel topics. These include the integration of the design and implementation of exercise interventions, exercise and dendritic spines, and exercise and neurophysiological mechanisms. Furthermore, an analysis of emerging keywords reveals that the current main research direction is exploring the specific physiological mechanisms through which exercise affects AD. This includes three emerging trends: the impact of exercise on cognitive impairment in AD patients, the effects of exercise on brain-derived neurotrophic factor (BDNF) and Amyloid beta, and the influence of exercise on Stress and neuroinflammation.

Conclusion

The research results indicate that interventions using exercise to alleviate the negative symptoms of AD, as well as combining exercise with medication for therapy, are gaining increasing attention from researchers. Meanwhile, novel topics such as exercise and music therapy, the design and implementation of exercise interventions, and neurophysiological mechanisms should also attract scholarly interest. Additionally, exploring the physiological mechanisms behind exercise therapy for AD could be a key focus for future research.

Targeting necroptosis in Alzheimer's disease: can exercise modulate neuronal death?

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline and neuronal degeneration. Emerging evidence implicates necroptosis in AD pathogenesis, driven by the RIPK1-RIPK3-MLKL pathway, which promotes neuronal damage, inflammation, and disease progression. Exercise, as a non-pharmacological intervention, can modulate key inflammatory mediators such as TNF-α, HMGB1, and IL-1β, thereby inhibiting necroptotic signaling. Additionally, exercise enhances O-GlcNAc glycosylation, preventing Tau hyperphosphorylation and stabilizing neuronal integrity. This review explores how exercise mitigates necroptosis and neuroinflammation, offering novel therapeutic perspectives for AD prevention and management.

Aerobic exercise improves clearance of amyloid-β via the glymphatic system in a mouse model of Alzheimer's Disease

BACKGROUND

Aerobic exercise training can promote the recovery of learning and memory ability in Alzheimer's disease (AD), but the specific mechanism is still unclear. Previous studies have suggested that aquaporin-4 (AQP4)-mediated glymphatic system is an important way to clear β-amyloid (Aβ) in the brain, which is closely related to learning and memory impairment in AD. However, it remains unclear whether AQP4 regulates glymphatic clearance of Aβ which contributes to the beneficial effects of aerobic exercise in AD patients. Here, the goal of this study was to investigate the mechanisms about aerobic exercise whether AQP4 could modulate glymphatic system using APP/PS1 mice.

METHODS

In this study, APP/PS1 AD model mice were treated with aerobic exercise intervention through swimming exercise training for 4 weeks, and the two groups of mice were injected with AQP4 inhibition virus and empty virus, respectively. Their learning and memory abilities were assessed using behavioral tests, such as the Barnes maze and Morris water maze tests. Hippocampus was obtained from sacrificed mice and used for histological analysis. Tracer imaging of the cerebellar medullary pool was used to observed the CSF-ISF exchange, immunohistochemistry was used to detect the level of Aβ plaques in the hippocampus of mice in each group; immunoblotting was used to detect the expression of AQP4 protein; immunofluorescence co-labeling was used to detect the polarization distribution of AQP4; qRT-PCR was used to detect the transcription levels of AQP4 and its anchoring proteins.

RESULTS

The funding showed that APP/PS1 mice have learning and memory impairment, and the glymphatic system is dysfunction. Swimming training can improve the ability of the glymphatic system to clear Aβ deposition in the hippocampus by up-regulating the transcription levels of Lama1 and Dp71 in the hippocampus, reducing the depolarization distribution of AQP4 in the hippocampus, and enhancing the exchange of CSF-ISF. Thus, improves learning and memory impairment in APP/PS1 mice.

CONCLUSIONS

Swimming training can rescue the function of the glymphatic system, increase the CSF-ISF exchange, promote the polarization distribution of AQP4, and reduce the deposition of Aβ in the hippocampus, thereby improving the learning and memory ability of APP/PS1 mice.

Optimal dose and type of non-pharmacological treatments to improve cognitive function in people with Alzheimer's disease: a systematic review and network meta-analysis

OBJECTIVES

To evaluate and rank the effectiveness of specific non-pharmacological treatments (NPTs) in improving the global cognitive function in individuals with Alzheimer's disease (AD) and to examine the dose-response relationship.

METHOD

We conducted a systematic search in PubMed, MEDLINE, Embase, PsycINFO, CENTRAL, WOS, and CNKI from their inception to 15 February 2023. Standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated for outcomes using random effects models.

RESULTS

We included 68 studies involving 5053 participants in this meta-analysis. The treatments with the highest cumulative probabilities for improving global cognitive function were transcranial direct current stimulation (tDCS), followed by physical exercise (PE), and repetitive transcranial magnetic stimulation (rTMS). Additionally, cognitive stimulation (CS), cognitive training CT), multidisciplinary program (MD), and reminiscence treatment (RT) also significantly improve the global cognitive function of people with AD. A non-linear dose-response association was observed for tDCS, PE, rTMS, CS, and CT with global cognitive improvement. Notably, no minimal threshold was identified for the beneficial effects of PE on cognition. The estimated minimal doses for clinically relevant changes in cognition were 33 min per week for tDCS, 330 MET-min per week for PE, and 8000 pulses per week for rTMS.

CONCLUSION

tDCS, PE, and rTMS are the better effective NPTs for enhancing global cognitive function in individuals with AD. Properly dosing these treatments can yield significant clinical benefits. Our findings support the clinical utility of low-dose exercise in improving cognition in people with AD.

The Impact of Hospice Care on the Prognosis, Quality of Life, and Emotional Well-being of Patients With Chronic Heart Failure

Chronic heart failure (CHF) represents a substantial public health challenge, impacting patients' emotional well-being, quality of life, and overall prognosis. Palliative care and hospice services are increasingly recognized in managing advanced CHF, yet their evidence-based benefits remain underexplored. This study aimed to assess the influence of hospice care on CHF patient outcomes. A total of 120 inpatients with CHF were randomly assigned to receive either hospice care in addition to standard treatment (experimental group) or standard care alone (control group). Patient assessments included heart function classification, activities of daily living, Minnesota Living With Heart Failure Questionnaire, anxiety scale, and pain assessment. Results demonstrated significant improvements in cardiac function, activities of daily living, anxiety levels, pain scores, and heart failure-related quality of life in the experimental group compared with controls. Reduced anxiety, enhanced emotional well-being, and overall health status improvements were particularly notable postintervention. Hospice care was associated with enhanced functional abilities, emotional well-being, pain management, and overall quality of life for CHF patients. In conclusion, this study underscores hospice care's positive impact on prognosis, quality of life, and emotional well-being in CHF, emphasizing its potential as a critical component in comprehensive CHF management strategies.

Twelve weeks of exercise training improves cognitive status, physical performance and quality of life in Alzheimer's disease: A systematic review and meta-analysis

Alzheimer's disease (AD) is a progressive neurodegenerative disorder in which there is slow and gradual impairment of mental function. Considering the increase in cases due to population aging, the potential benefits of physical training in AD are of great importance and need further elucidation. This study aims to identify the impact of physical training on crucial aspects of AD such as cognitive status, physical performances, quality of life and activities of daily living. The bibliographic research was conducted according to the guidelines outlined in PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis). After the selection process, 26 studies were included in the systematic review and meta-analysis. Physical training for up to 12 weeks had a moderate effect on the cognitive status (SMD: 0.34; 95 % CI: 0.07-0.61; p = 0.016), the physical performance (SMD: 0.75; 95 % CI: 0.43-1.06; p = 0.000) and the quality of life (SMD: 0.40; 95 % CI: 0.17-0.63; p = 0.567) of patients with AD, but did not affect their daily living activities (SMD: -0.10; 95 % CI: -0.31-0.12; p = 0.621). Physical training lasting from 16 to 24 weeks had a moderate effect only on the physical performance (SMD: 0.51; 95 % CI: 0.23-0.79; p = 0.000) of patients. Physical training for up to 12 weeks already leads to gains on the cognition, the physical performance and the quality of life of individuals with AD. Beyond the available evidence on health promotion resulting from physical training, guidelines should be established to define ideal training loads for patients with AD. Specific practical recommendations concerning the types, frequency, intensity or duration of physical exercise that may be the most efficient for ameliorating cognition, physical performance and quality of life of individuals with AD are still unclear.

A review of the application of exercise intervention on improving cognition in patients with Alzheimer's disease: mechanisms and clinical studies

Alzheimer's disease (AD) is the most common form of dementia, leading to sustained cognitive decline. An increasing number of studies suggest that exercise is an effective strategy to promote the improvement of cognition in AD. Mechanisms of the benefits of exercise intervention on cognitive function may include modulation of vascular factors by affecting cardiovascular risk factors, regulating cardiorespiratory health, and enhancing cerebral blood flow. Exercise also promotes neurogenesis by stimulating neurotrophic factors, affecting neuroplasticity in the brain. Additionally, regular exercise improves the neuropathological characteristics of AD by improving mitochondrial function, and the brain redox status. More and more attention has been paid to the effect of Aβ and tau pathology as well as sleep disorders on cognitive function in persons diagnosed with AD. Besides, there are various forms of exercise intervention in cognitive improvement in patients with AD, including aerobic exercise, resistance exercise, and multi-component exercise. Consequently, the purpose of this review is to summarize the findings of the mechanisms of exercise intervention on cognitive function in patients with AD, and also discuss the application of different exercise interventions in cognitive impairment in AD to provide a theoretical basis and reference for the selection of exercise intervention in cognitive rehabilitation in AD.

Effects of aerobic exercise on cognitive function and quality of life in patients with Alzheimer's disease: a systematic review and meta-analysis

OBJECTIVES

Numerous studies have examined the effects of physical activity on cognitive performance and executive function in people with Alzheimer's disease (AD), although the findings are not entirely consistent. There are also insufficient study reviews for specific workout and assessment tool types. Therefore, the purpose of this study was to systematically investigate the effects of aerobic exercise on the quality of life, cognitive performance and depressive symptoms in people with AD.

DESIGN

Risk of bias was assessed using the Cochrane risk of bias tool, systematic reviews and meta-analyses using random-effects modelling, and certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation tool.

DATA SOURCES

PubMed, Web of Science, Cochrane Library, EMBASE, Scopus, CINAHL and CNKI through 12 March 2024.

ELIGIBILITY CRITERIA

The analysis includes all randomised controlled trials (RCTs) that used aerobic exercise as an intervention for individuals with AD.

DATA EXTRACTION AND SYNTHESIS

Two writers selected and searched for data using defined techniques. To investigate possible sources of heterogeneity between studies, meta-regression was carried out using Stata MP V.18.0 and V.14.0 software, standardised mean differences (SMDs) and 95% CIs were computed, and data were reviewed using Review Manager V.5.4 software, which was made available by the Cochrane Collaboration. Sensitivity analyses were employed to ascertain the stability and reliability of the results, and funnel plots and Egger's test were employed to check for publication bias. Correction and assessment of publication bias was done using Duval and Tweedie clipping methods.

RESULTS

Aerobic exercise enhanced cognitive function. For the Minimum Mental State Examination (MMSE) (SMD=0.95, 95% CI 0.58 to 1.32, Z=5.06, p<0.00001), Alzheimer's Disease Assessment Scale-Cognitive Section (ADAS-cog) (SMD=-0.67, 95% CI -1.15 to -0.2, Z=2.77, p=0.006) and quality of life (SMD=0.36, 95% CI 0.08 to 0.64, Z=2.51, p=0.01), but not statistically significant for depressive symptoms (SMD=-0.25, 95% CI -0.63 to 0.13, Z=1.27, p=0.21). Subgroup analysis showed that duration greater than 16 weeks and less than 50 min per intervention improved MMSE Scores. Duration greater than 16 weeks and more than 30 min per intervention improved ADAS-cog Scores in patients with AD. Aerobic exercise greater than 16 weeks, with more than three interventions per week and 30-50 min per intervention improves quality of life in patients with AD.

CONCLUSION

The study revealed that aerobic exercise was conducive to the improvement of cognitive function and quality of life among patients with AD, yet it did not exert a significant impact on the amelioration of depressive symptoms. Nevertheless, given the high level of heterogeneity and the variations in the quality of the included studies, the conclusions require further verification through more scientifically objective RCTs.

PROSPERO REGISTRATION NUMBER

CRD42024526067.

Association between serum albumin and severe impairment of activities of daily living in patients with stroke: a cross-sectional study

Purpose

The relationship between serum albumin levels and severe limitations in ADLs among stroke patients remains unclear. Specifically, the dose-response relationship between the two needs further exploration. This study aims to provide further results.

Materials and methods

This study examined cross-sectional data from patients aged 18 years or older with a diagnosis of stroke confirmed by cranial CT or MRI within 24 h of admission, gathered from January 2020 to August 2022. Data included serum albumin levels, Barthel Index scores recorded after admission, and other essential variables.

Results

The study comprised 2,393 stroke patients. After adjusting for confounding factors, the multivariate analysis revealed a 7% decrease in severe impairment of ADL after stroke for every unit (g/L) increase in serum albumin levels. Compared with individuals with lower serum albumin levels (Q1: ≤ 37.4 g/L), the adjusted odds ratios (OR) for severe of ADL impairment among stroke patients in Q2 (37.4-40.21 g/L), Q3 (40.21-42.80 g/L), and Q4 (≥42.8 g/L) were 0.68 (95% CI: 0.4-1.15, p = 0.148), 0.55 (95% CI: 0.32-0.97, p = 0.04), and 0.64 (95% CI: 0.37-1.15, p = 0.139), respectively. The relationship between serum albumin and severe impairment of ADLs in stroke patients showed an L-shaped curve (non-linear, p = 0.002), with an inflection point at 38.0 g/L. The OR for significant impairment of ADLs was 0.680 (95% CI: 0.568-0.814, p < 0.001) in participants with serum albumin levels <38.0 g/L. However, when serum albumin levels were greater than or equal to 38.0 g/L, the severe impairment of ADLs no longer decreased with rising serum albumin levels.

Conclusion

In summary, an L-shaped connection with an approximate inflection point of 38.0 g/L was found between blood albumin levels and significant ADL impairment in stroke patients. The results of this study suggest that increasing serum albumin levels can significantly help improve the severity of ADL impairment in stroke patients, particularly those with serum albumin levels below 38.0 g/L.

Different physical exercise in the treatment of Alzheimer's disease

Alzheimer's disease (AD) is rapidly becoming one of the most expensive, burdening, and deadly diseases of this century. Up to now, there is still a lack of pharmacotherapy with substantial efficacy, and physical exercise is a promising and low-cost way to aid in delaying the process of AD. The aim of this review is to summarise the efficacy of different physical exercise approaches and doses in the management of AD, including aerobic exercise, resistance exercise and multicomponent exercise. A literature search using MeSH terms for each topic is undertaken using PubMed and the Web of Science Core Collection database, supplemented by hand searching for additional references. Retrieved articles were reviewed, synthesised, and summarised. This review shows that aerobic exercise has been almost unanimously recognised for the improvement of cognition, neuropsychiatric symptoms and activities of daily living. Resistance exercise also shows a good prospect in the above aspects and has a unique advantage in enhancing muscle strength, while multicomponent physical activity does not seen to significantly improve cognitive function. Each type of exercise has a dose effect, but for individuals with AD, the most appropriate exercise dose is still controversial.

Effects of human concurrent aerobic and resistance training on cognitive health: A systematic review with meta-analysis

Background

The rising prevalence of cognitive decline and neurodegenerative diseases, projected to affect 150 million individuals by 2050, highlights the urgent need to enhance neurocognitive health. While both aerobic and resistance training are recognized as effective strategies, their combined effects on cognition remain underexplored.

Objective

This study aimed to determine if concurrent aerobic and resistance training (CT) is effective in enhancing cognitive function.

Methods

Seven English and three Chinese databases were searched from inception to August 2024. Randomised controlled trials (RCTs) examining the effects of CT on global cognition across diverse populations were included. A meta-analysis was performed using a random-effects model in R and Stata, supplemented by subgroup and meta-regression analyses to explore variability.

Results

The meta-analysis included 35 RCTs with 5,734 participants, revealing a positive effect of CT on global cognition (g = 0.32, 95% CI: 0.17-0.46, p < 0.001). Notably, older adults (≥65 years) exhibited greater cognitive benefits (g = 0.33; 95% CI: 0.14-0.51, p < 0.05) compared to younger populations. Significant effects were also observed in clinical populations (g = 0.28; 95% CI: 0.11-0.46, p < 0.001). Exercise frequency and duration positively influenced outcomes, with medium-length interventions (13-26 weeks) demonstrating significant effects (g = 0.21; 95% CI: 0.05-0.37, p = 0.011).

Conclusion

The findings indicate that CT significantly enhances cognitive health, particularly in older adults and clinical populations. Prioritizing strength training, implementing short- to medium-term interventions (4-26 weeks), and maintaining session durations of 30-60 minutes are crucial for optimizing cognitive benefits.

Understanding the Molecular Impact of Physical Exercise on Alzheimer's Disease

Alzheimer's disease is one of the most common neurodegenerative diseases, characterized by a wide range of neurological symptoms that begin with personality changes and psychiatric symptoms, progress to mild cognitive impairment, and eventually lead to dementia. Physical exercise is part of the non-pharmacological treatments used in Alzheimer's disease, as it has been shown to delay the neurodegenerative process by improving the redox state in brain tissue, providing anti-inflammatory effects or stimulating the release of the brain-derived neurotrophic factor that enhances the brain structure and cognitive performance. Here, we reviewed the results obtained from studies conducted in both animal models and human subjects to comprehend how physical exercise interventions can exert changes in the molecular mechanisms underlying the pathophysiological processes in Alzheimer's disease: amyloid β-peptide pathology, tau pathology, neuroglial changes, mitochondrial dysfunction, and oxidative stress. Physical exercise seems to have a protective effect against Alzheimer's disease, since it has been shown to induce positive changes in some of the biomarkers related to the pathophysiological processes of the disease. However, additional studies in humans are necessary to address the current lack of conclusive evidence.

The emerging role of exercise in Alzheimer's disease: Focus on mitochondrial function

Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by memory impairment and cognitive dysfunction, which eventually leads to the disability and mortality of older adults. Although the precise mechanisms by which age promotes the development of AD remains poorly understood, mitochondrial dysfunction plays a central role in the development of AD. Currently, there is no effective treatment for this debilitating disease. It is well accepted that exercise exerts neuroprotective effects by ameliorating mitochondrial dysfunction in the neurons of AD, which involves multiple mechanisms, including mitochondrial dynamics, biogenesis, mitophagy, transport, and signal transduction. In addition, exercise promotes mitochondria communication with other organelles in AD neurons, which should receive more attentions in the future.

Symptom-specific non-pharmacological interventions for behavioral and psychological symptoms of dementia: An umbrella review

BACKGROUND

Non-pharmacological interventions are considered the first-line treatment for managing the behavioral and psychological symptoms of dementia. Given the heterogeneous characteristics of these symptoms, which vary for each individual and tend to fluctuate, a symptom-specific approach is necessary for providing individualized non-pharmacological interventions for people with dementia. However, clear guidelines regarding the appropriate types of interventions for individual symptoms or clusters of behavioral and psychological symptoms of dementia are lacking.

OBJECTIVES

The aim of this umbrella review was to summarize the current evidence on non-pharmacological interventions for behavioral and psychological symptoms of dementia and provide guidance for determining the appropriate types of interventions for each behavioral and psychological symptom of dementia.

DESIGN

An umbrella review of systematic reviews and/or meta-analyses.

METHODS

The Cochrane methodology for umbrella reviews was employed for this review, and the review protocol was registered. PubMed, CINAHL, Embase, PsycINFO, and Cochrane databases were searched for relevant reviews using the 'population, intervention, control, and outcomes' formulation. Two reviewers independently screened the extracted articles for eligibility. The quality of each selected review was independently assessed by the two reviewers using A Measurement Tool to Assess Systematic Reviews 2. The results were narratively synthesized and categorized according to each symptom.

RESULTS

Thirty-five systematic reviews, 71 % of which were also meta-analyses, were included in this review. The methodologies employed in the included reviews were significantly heterogeneous. The qualities of the reviews ranged from low to moderate. Diverse types of non-pharmacological interventions were identified in the reviews, with music therapy being the most frequently discussed. Among the various symptoms, depression was most frequently addressed, followed by overall symptoms, agitation, anxiety, sleep problems, and apathy. Music therapy was found to be effective for improving both overall and specific symptoms, including depression and anxiety. Notably, relatively weak evidence supports the effectiveness of exercise in addressing each symptom. Aromatherapy could be considered for agitation, whereas reminiscence may be effective in managing overall and specific symptoms, such as depression.

CONCLUSIONS

The results showed that the evidence of symptom-specific effectiveness of non-pharmacological interventions varied across the different behavioral and psychological symptoms of dementia, highlighting the need for a symptom-specific approach in future research. Furthermore, future research is needed to facilitate the development of symptom-specific guidelines that can enhance the quality of individualized dementia care.

REGISTRATION

Registered with PROSPERO (number: CRD42022340930) on November 9, 2022.

Lactate/Hydroxycarboxylic Acid Receptor 1 in Alzheimer's Disease: Mechanisms and Therapeutic Implications-Exercise Perspective

Lactate has a novel function different from previously known functions despite its traditional association with hypoxia in skeletal muscle. It plays various direct and indirect physiological functions. It is a vital energy source within the central nervous system (CNS) and a signal transmitter regulating crucial processes, such as angiogenesis and inflammation. Activating lactate and its associated receptors elicits effects like synaptic plasticity and angiogenesis alterations. These effects can significantly influence the astrocyte-neuron lactate shuttle, potentially impacting cognitive performance. Decreased cognitive function relates to different neurodegenerative conditions, including Alzheimer's disease (AD), ischemic brain injury, and frontotemporal dementia. Therefore, lactic acid has significant potential for treating neurodegenerative disorders. Exercise is a method that induces the production of lactic acid, which is similar to the effect of lactate injections. It is a harmless and natural way to achieve comparable results. Animal experiments demonstrate that high-intensity intermittent exercise can increase vascular endothelial growth factor (VEGF) levels, thus promoting angiogenesis. In vivo, lactate receptor-hydroxycarboxylic acid receptor 1 (HCAR1) activation can occur by various stimuli, including variations in ion concentrations, cyclic adenosine monophosphate (cAMP) level elevations, and fluctuations in the availability of energy substrates. While several articles have been published on the benefits of physical activity on developing Alzheimer's disease in the CNS, could lactic acid act as a bridge? Understanding how HCAR1 responds to these signals and initiates associated pathways remains incomplete. This review comprehensively analyzes lactate-induced signaling pathways, investigating their influence on neuroinflammation, neurodegeneration, and cognitive decline. Consequently, this study describes the unique role of lactate in the progression of Alzheimer's disease.

Factors Affecting Resilience and Prevention of Alzheimer's Disease and Related Dementias

Alzheimer's disease (AD) is a devastating, age-associated neurodegenerative disorder and the most common cause of dementia. The clinical continuum of AD spans from preclinical disease to subjective cognitive decline, mild cognitive impairment, and dementia stages (mild, moderate, and severe). Neuropathologically, AD is defined by the accumulation of amyloid β (Aβ) into extracellular plaques in the brain parenchyma and in the cerebral vasculature, and by abnormally phosphorylated tau that accumulates intraneuronally forming neurofibrillary tangles (NFTs). Development of treatment approaches that prevent or even reduce the cognitive decline because of AD has been slow compared to other major causes of death. Recently, the United States Food and Drug Administration gave full approval to 2 different Aβ-targeting monoclonal antibodies. However, this breakthrough disease modifying approach only applies to a limited subset of patients in the AD continuum and there are stringent eligibility criteria. Furthermore, these approaches do not prevent progression of disease, because other AD-related pathologies, such as NFTs, are not directly targeted. A non-mutually exclusive alternative is to address lifestyle interventions that can help reduce the risk of AD and AD-related dementias (ADRD). It is estimated that addressing such modifiable risk factors could potentially delay up to 40% of AD/ADRD cases. In this review, we discuss some of the many modifiable risk factors that may be associated with prevention of AD/ADRD and/or increasing brain resilience, as well as other factors that may interact with these modifiable risk factors to influence AD/ADRD progression. [Color figure can be viewed at www.annalsofneurology.org] ANN NEUROL 2024;96:633-649.

Neurodegenerative disorders, metabolic icebergs, and mitohormesis

Neurodegenerative disorders are typically "split" based on their hallmark clinical, anatomical, and pathological features, but they can also be "lumped" by a shared feature of impaired mitochondrial biology. This leads us to present a scientific framework that conceptualizes Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD) as "metabolic icebergs" comprised of a tip, a bulk, and a base. The visible tip conveys the hallmark neurological symptoms, neurodegenerative regions, and neuronal protein aggregates for each disorder. The hidden bulk depicts impaired mitochondrial biology throughout the body, which is multifaceted and may be subdivided into impaired cellular metabolism, cell-specific mitotypes, and mitochondrial behaviours, functions, activities, and features. The underlying base encompasses environmental factors, especially modern industrial toxins, dietary lifestyles, and cognitive, physical, and psychosocial behaviours, but also accommodates genetic factors specific to familial forms of AD, PD, and ALS, as well as HD. Over years or decades, chronic exposure to a particular suite of environmental and genetic factors at the base elicits a trajectory of impaired mitochondrial biology that maximally impacts particular subsets of mitotypes in the bulk, which eventually surfaces as the hallmark features of a particular neurodegenerative disorder at the tip. We propose that impaired mitochondrial biology can be repaired and recalibrated by activating "mitohormesis", which is optimally achieved using strategies that facilitate a balanced oscillation between mitochondrial stressor and recovery phases. Sustainably harnessing mitohormesis may constitute a potent preventative and therapeutic measure for people at risk of, or suffering with, neurodegenerative disorders.

Crosstalk between bone and brain in Alzheimer's disease: Mechanisms, applications, and perspectives

Alzheimer's disease (AD) is a neurodegenerative disease that involves multiple systems in the body. Numerous recent studies have revealed bidirectional crosstalk between the brain and bone, but the interaction between bone and brain in AD remains unclear. In this review, we summarize human studies of the association between bone and brain and provide an overview of their interactions and the underlying mechanisms in AD. We review the effects of AD on bone from the aspects of AD pathogenic proteins, AD risk genes, neurohormones, neuropeptides, neurotransmitters, brain-derived extracellular vesicles (EVs), and the autonomic nervous system. Correspondingly, we elucidate the underlying mechanisms of the involvement of bone in the pathogenesis of AD, including bone-derived hormones, bone marrow-derived cells, bone-derived EVs, and inflammation. On the basis of the crosstalk between bone and the brain, we propose potential strategies for the management of AD with the hope of offering novel perspectives on its prevention and treatment. HIGHLIGHTS: The pathogenesis of AD, along with its consequent changes in the brain, may involve disturbing bone homeostasis. Degenerative bone disorders may influence the progression of AD through a series of pathophysiological mechanisms. Therefore, relevant bone intervention strategies may be beneficial for the comprehensive management of AD.

Effects of cardiac rehabilitation on cognitive function in patients with acute coronary syndrome: A systematic review

Background

Construction of an intervention method for the cognitive dysfunction of patients with acute coronary syndrome (ACS) is needed. Exercise-based comprehensive cardiac rehabilitation is a potentially effective approach that can improve cognitive function in ACS patients. This study aimed to investigate the effect of cardiac rehabilitation on cognitive function in ACS patients through a systematic review.

Methods

A systematic review was conducted of studies on PubMed, MEDLINE, Web of Science, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) on September 13, 2022, to identify those reporting the effects of cardiac rehabilitation on cognitive function in ACS patients. Data that reported exercise-based comprehensive cardiac rehabilitation and cognitive function (even if not main results and any type of cognitive function assessment was used) were extracted.

Results

In total, six studies were included that comprised a total of 1085 ACS patients. Overall positive effects of cardiac rehabilitation on cognitive function in ACS patients were reported across the six studies. All studies included aerobic exercise, resistance exercise, and patient education in cardiac rehabilitation. Meta-analysis could not be undertaken because each dataset used different methods to evaluate cognitive function, and the outcomes were different.

Conclusions

This systematic review showed that cardiac rehabilitation could have positive effects on cognitive function in ACS patients. Our results support the efficacy of cardiac rehabilitation for cognitive function in ACS patients. Additional well-designed clinical trials of exercise-based comprehensive cardiac rehabilitation should be conducted to clarify the true effect on cognitive function in ACS patients.

Exercise to Counteract Alzheimer's Disease: What Do Fluid Biomarkers Say?

Neurodegenerative diseases (NDs) represent an unsolved problem to date with an ever-increasing population incidence. Particularly, Alzheimer's disease (AD) is the most widespread ND characterized by an accumulation of amyloid aggregates of beta-amyloid (Aβ) and Tau proteins that lead to neuronal death and subsequent cognitive decline. Although neuroimaging techniques are needed to diagnose AD, the investigation of biomarkers within body fluids could provide important information on neurodegeneration. Indeed, as there is no definitive solution for AD, the monitoring of these biomarkers is of strategic importance as they are useful for both diagnosing AD and assessing the progression of the neurodegenerative state. In this context, exercise is known to be an effective non-pharmacological management strategy for AD that can counteract cognitive decline and neurodegeneration. However, investigation of the concentration of fluid biomarkers in AD patients undergoing exercise protocols has led to unclear and often conflicting results, suggesting the need to clarify the role of exercise in modulating fluid biomarkers in AD. Therefore, this critical literature review aims to gather evidence on the main fluid biomarkers of AD and the modulatory effects of exercise to clarify the efficacy and usefulness of this non-pharmacological strategy in counteracting neurodegeneration in AD.

"When she goes out, she feels better:" co-designing a Green Activity Program with Hispanic/Latino people living with memory challenges and care partners

Purpose

Utilizing a participatory approach, we sought to co-design a 12-week Green Activity Program (GAP) with Hispanic/Latino individuals living with memory challenges and their care partners, local outdoor professionals, and healthcare providers.

Methods

Participants were recruited via convenience and snowball sampling in the Bronx, New York with Hispanic/Latino persons living with memory challenges and care partners, outdoor activity professionals, and interdisciplinary healthcare providers/dementia experts. Co-design occurred iteratively with 5 focus groups and 4 individual interviews lasting 30-90 min and focused on program and research design. Sessions were recorded and transcribed. Utilizing directed content analysis data was coded using a priori codes program design and research design.

Results

21 participants completed co-design activities: (n = 8 outdoor activity professionals, n = 6 Hispanic/Latino persons living with memory challenges and care partners, and n = 7 interdisciplinary healthcare providers/dementia experts). Participant preferences for program design were captured by subcodes session duration (30-90 min), frequency (4-8 sessions), and delivery modes (in-person and phone). Participants' preferred nature activities included group exercise and outdoor crafts [crocheting], outcomes of social participation, connectedness to nature, decreased loneliness, and stewardship were identified. Preferred language for recruiting and describing the program were "memory challenges," "Hispanic/Latino," and "wellbeing." Referral pathways were identified including community-based organizations and primary care.

Conclusion

Co-design was a successful form of engagement for people living with memory challenges that enabled participants to help design key elements of the GAP and research design. Our processes, findings, and recommendations for tailoring co-design to engage Hispanic/Latino people living with memory challenges can inform the development of other programs for this population.

Multisensory Fusion Training and 7, 8-Dihydroxyflavone Improve Amyloid-β-Induced Cognitive Impairment, Anxiety, and Depression-Like Behavior in Mice Through Multiple Mechanisms

Background

There is growing interest in the role of physical activity in patients with of Alzheimer's disease (AD), particularly regarding its impact of cognitive function, gut microbiota, metabolites, and neurotrophic factors.

Objective

To investigate the impact of multisensory fusion training (MSFT) combined with 7, 8-dihydroxyflavone (DHF) on the behavioral characteristics, protein expression, microbiome, and serum metabolome using the AD model in mice induced with amyloid-β (Aβ).

Methods

We assessed cognitive ability, anxiety-like and depression-like behaviors in Aβ mice using behavioral measures. Western blotting was employed to detect the expression of relevant proteins. The 16S rRNA gene sequencing and metabolomics were used to analyze changes in the intestinal microbial composition and serum metabolic profile, respectively, of Aβ mice.

Results

The behavioral outcomes indicated that a 4-week intervention combining DHF and MSFT yielded remarkable improvements in cognitive function and reduced anxiety and depression-like behaviors in Aβ mice. In the hippocampus of Aβ mice, the combined intervention increased the levels of BDNF, VGF, PSD-95, Nrf2, p-GSK3β and p-CREB proteins. Analyses of sequence and metabolomic data revealed that Bacteroides and Ruminococcaceae were remarkably more abundant following the combined intervention, influencing the expression of specific metabolites directly linked to the maintenance of neuronal and neurobehavioral functions. These metabolites play a crucial role in vital processes, such as amino acid metabolism, lipid metabolism, and neurotransmitter metabolism in mice.

Conclusion

Our study highlighted that MSFT combined with DHF improves cognitive impairment, anxiety, and depression-like behavior in Aβ mice through multiple mechanisms, and further validated the correlation between the gut microbiome and serum metabolome. These findings open up a promising avenue for future investigations into potential treatment strategies for AD.

Effective dosage and mode of exercise for enhancing cognitive function in Alzheimer's disease and dementia: a systematic review and Bayesian Model-Based Network Meta-analysis of RCTs

OBJECTIVE

Research the dose-response relationship between overall and certain types of exercise and cognitive function in older adults with Alzheimer's disease and dementia.

DESIGN

Systemic and Bayesian Model-Based Network Meta-Analysis.

METHODS

In our study, we analyzed data from randomized controlled trials investigating the effects of different exercises on cognitive outcomes in older adults with AD. We searched the Web of Science, PubMed, Cochrane Central Register of Controlled Trials, and Embase up to November 2023. Using the Cochrane Risk of Bias tool (Rob2) for quality assessment and R software with the MBNMA package for data analysis, we determined standard mean differences (SMDs) and 95% confidence intervals (95%CrI) to evaluate exercise's impact on cognitive function in AD.

RESULTS

Twenty-seven studies with 2,242 AD patients revealed a nonlinear relationship between exercise and cognitive improvement in AD patients. We observed significant cognitive enhancements at an effective exercise dose of up to 1000 METs-min/week (SMDs: 0.535, SD: 0.269, 95% CrI: 0.023 to 1.092). The optimal dose was found to be 650 METs-min/week (SMDs: 0.691, SD: 0.169, 95% CrI: 0.373 to 1.039), with AE (Aerobic exercise) being particularly effective. For AE, the optimal cognitive enhancement dose was determined to be 660 METs-min/week (SMDs: 0.909, SD: 0.219, 95% CrI: 0.495 to 1.362).

CONCLUSION

Nonlinear dose-response relationship between exercise and cognitive improvement in Alzheimer's disease, with the optimal AE dose identified at 660 METs-min/week for enhancing cognitive function in AD.

Effects of home-based and telerehabilitation exercise on mental and physical health, and disease cost in people with Alzheimer's disease: A meta-analysis

BACKGROUND

Alzheimer's disease (AD) is a very disabling long-term disease that requires continuous regular care. A cost-effective and sustainable means of such care may be physical activity or exercise delivered at home or through telerehabilitation. The aim of this study is to determine the effects of home-based or telerehabilitation exercise in people with AD.

METHOD

PubMED, Embase, Web of Science (WoS), PEDro, and CENTRAL were searched for randomized controlled trials until January 2024. The data extracted include the characteristics of the participants, the interventions used for both experimental and the control groups, the baseline, post-intervention and follow-up mean and standard deviation values on the outcomes assessed and the findings of the included studies. Cochrane risks of bias assessment tool and PEDro scale were used to assess the risks of bias and methodological quality of the studies. The results were analyzed using narrative and quantitative syntheses.

RESULT

Eleven articles from nine studies (n=550) were included in the study. The results showed that, only global cognitive function (SMD = 0.72, 95% CI = 0.19-1.25, p=0.007), neuropsychiatric symptom (MD = -5.28, 95% CI =-6.22 to -4.34, p<0.0001) and ADL (SMD =3.12, 95% CI =0.11-6.13, p=0.04) improved significantly higher in the experimental group post-intervention. At follow-up, the significant difference was maintained only in neuropsychiatric symptoms (MD =-6.20, 95% CI =-7.17 to -5.23, p<0.0001).

CONCLUSION

There is a low evidence on the effects of home-based physical activity or exercise on global cognitive function, neuropsychiatric symptoms and ADL.

The impact of exercise on Alzheimer's disease progression

INTRODUCTION

The preventive effects of chronic physical exercise (CPE) on Alzheimer's disease (AD) are now admitted by the scientific community. Curative effects of CPE are more disputed, but they deserve to be investigated, since CPE is a natural non-pharmacological alternative for the treatment of AD.

AREAS COVERED

In this perspective, the authors discuss the impact of CPE on AD based on an exhaustive literature search using the electronic databases PubMed, ScienceDirect and Google Scholar.

EXPERT OPINION

Aerobic exercise alone is probably not the unique solution and needs to be complemented by other exercises (physical activities) to optimize the slowing down of AD. Anaerobic, muscle strength and power, balance/coordination and meditative exercises may also help to slow down the AD progression. However, the scientific evidence does not allow a precise description of the best training program for patients with AD. Influential environmental conditions (e.g. social relations, outdoor or indoor exercise) should also be studied to optimize training programs aimed at slowing down the AD progression.

Clinical evidence of hyperbaric oxygen therapy for Alzheimer's disease: a systematic review and meta-analysis of randomized controlled trials

Objective

To evaluate the potential benefits of hyperbaric oxygen intervention on people with Alzheimer's disease (AD) based on the existing randomized controlled trials (RCTs).

Methods

A systematic search was conducted in nine databases until November 17, 2023, for RCTs assessing the effect of hyperbaric oxygen intervention for AD. The primary outcomes included Mini-Mental State Examination (MMSE), Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog), activities of daily living (ADL), and adverse events. All results were shown in forest plots, and sensitivity analysis was adopted to further verify the robustness of the pooled results.

Results

A total of 11 RCTs recruiting 847 participants were included in this meta-analysis. Based on the pooled evidence, hyperbaric oxygen could remarkably ameliorate MMSE [MD = 3.08, 95%CI (2.56, 3.61), p < 0.00001], ADAS-Cog [MD = -4.53, 95%CI (-5.05, -4.00), p < 0.00001], ADL [MD = 10.12, 95%CI (4.46, 15.79), p = 0.0005], MDA levels [SMD = -2.83, 95%CI (-5.27, -0.38), p = 0.02], SOD levels [SMD = 2.12, 95%CI (1.10, 3.15), p < 0.0001], IL-1-β levels [SMD = -1.00, 95%CI (-1.48, -0.53), p < 0.0001], and TGF-β1 levels [MD = 4.87, 95%CI (3.98, 5.76), p < 0.00001] without adverse events [OR = 1.17, 95%CI (0.68, 2.03), p = 0.58] for people with AD. The pooled results were robust after checking by sensitivity analysis.

Conclusion

These evidences suggest that hyperbaric oxygen is an effective and safe intervention for the treatment of AD. Further studies with more rigorous design will help to fully evaluate the clinical value of hyperbaric oxygen on cognition function in people with AD.

Systematic review registration

https://www.crd.york.ac.uk, identifier CRD42023483726.

Physical exercise frequency and cognition: a multicenter cross-sectional cohort study

Background and aims

Dementia imposes a heavy burden on society and families, therefore, effective drug treatments, exploring and preventing factors associated with dementia, are paramount. To provide reference points for the best frequency of physical exercise (physical exercise), we investigated the association between frequency of PE and cognition in Chinese old adults.

Methods

16,181 Chinese participants aged 65 years or older were included in this study. Associations between PE and cognition were estimated multivariate logistic and linear regression analyses. Associations were further investigated across dementia subtypes (Alzheimer dementia, vascular dementia, and other types of dementia). Subgroup analyses were performed in different age groups, in populations with and without stroke, and those with and without hypertension.

Results

PE associated with dementia after adjusting for full covariates (OR: 0.5414, 95% CI: 0.4536-0.6491, p < 0.001). Exercise performed at ≥3 times/week associated with lower risk of dementia (OR: 0.4794-0.6619, all p value <0.001). PE was associated with improved cognition (β: 12851, p < 0.001), and any PE frequency contributed to cognitive improvement (p values for exercise performed ≥1 time/week were <0.001). Similar conclusions were identified when we repeated analyses in different dementia subtypes and age groups. Subgroup analyses suggested that the cognition of individuals without hypertension also benefitted from exercising 1-2 times/week (OR: 0.6168, 95% CI: 0.4379-0.8668, p = 0.005).

Conclusion

The best exercise frequency is exercising ≥3 times/week for individuals from different dementia subtypes and age groups. While for those without hypertension, PE at 1-2 times /week is also beneficial.

Intrinsic functional brain connectivity changes following aerobic exercise, computerized cognitive training, and their combination in physically inactive healthy late-middle-aged adults: the Projecte Moviment

Lifestyle interventions have positive neuroprotective effects in aging. However, there are still open questions about how changes in resting-state functional connectivity (rsFC) contribute to cognitive improvements. The Projecte Moviment is a 12-week randomized controlled trial of a multimodal data acquisition protocol that investigated the effects of aerobic exercise (AE), computerized cognitive training (CCT), and their combination (COMB). An initial list of 109 participants was recruited from which a total of 82 participants (62% female; age = 58.38 ± 5.47) finished the intervention with a level of adherence > 80%. Only in the COMB group, we revealed an extended network of 33 connections that involved an increased and decreased rsFC within and between the aDMN/pDMN and a reduced rsFC between the bilateral supplementary motor areas and the right thalamus. No global and especially local rsFC changes due to any intervention mediated the cognitive benefits detected in the AE and COMB groups. Projecte Moviment provides evidence of the clinical relevance of lifestyle interventions and the potential benefits when combining them.

Understanding the mechanisms of disease modifying effects of aerobic exercise in people with Alzheimer's disease

Alzheimer's disease (AD) is a very disabling disease. Pathologically, it is characterized by the presence of amyloid plaques and neurofibrillary tangles in the brain that results in neurodegeneration. Its clinical manifestations include progressive memory impairment, language decline and difficulty in carrying out activities of daily living (ADL). The disease is managed using interventions such as pharmacological interventions and aerobic exercise. Use of aerobic exercise has shown some promises in reducing the risk of developing AD, and improving cognitive function and the ability to carry out both basic and instrumental ADL. Although, the mechanisms through which aerobic exercise improves AD are poorly understood, improvement in vascular function, brain glucose metabolism and cardiorespiratory fitness, increase in antioxidant capacity and haemoglobin level, amelioration of immune-related and inflammatory responses, modulation of concentration of circulating Neurotrophins and peptides and decrease in concentration of tau protein and cortisol level among others seem to be the possible mechanisms. Therefore, understanding these mechanisms is important to help characterize the dose and the nature of the aerobic exercise to be given. In addition, they may also help in finding ways to optimize other interventions such as the pharmacological interventions. However, more quality studies are needed to verify the mechanisms.

Comparative efficacy of various exercise interventions on sleep in patients with cognitive impairment: a systematic review and meta-analysis

Background

Sleep disturbances are an early indicator of cognitive impairment and exacerbate its progression. While pharmacological treatments for sleep disorders exist, their side-effect profile includes an increased risk of falls and the potential to exacerbate cognitive impairment. Non-pharmacological treatments such as physical exercise should be considered. However, uncertainties persist. We aimed to assess the potential benefits of exercise interventions on sleep in patients with cognitive impairment and determine the specific effects of various exercise modalities.

Materials and methods

A systematic search was performed on seven databases for eligible studies published before Nov 2022. Randomized controlled trials of exercise for patients with cognitive impairment (mild cognitive impairment and Alzheimer's disease) were included. All analyses were conducted using RevMan version 5.4. Meta-analysis and The Grading of Recommendations Assessment Development and Evaluations (GRADE) quality ratings were performed on sleep quality and objective sleep data.

Results

A total of 8 randomized controlled trials were included with a sample size of 486 subjects. For patients with cognitive impairment, physical exercise had a beneficial effect on sleep quality [MD = -3.55 (-5.57, -1.32), Z = 3.13, p = 0.002] and total sleep time [MD = 33.77 (23.92, 43.62), Z = 6.72, P < 0.00001]. No improvement was found in sleep efficiency and nocturnal awakening time. Subgroup analysis showed that multi-component exercise produced superior results.

Conclusion

Physical exercise may improve sleep quality and total sleep time for patients with cognitive impairment. Multi-component exercise designed individually is more effective. Large-scale randomized controlled trials with objective sleep outcome measurements are warranted.Clinical trial registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42022377221.

Irisin limits amyloid-β buildup in Alzheimer's disease

Mounting evidence suggests that physical exercise protects the brain against neurodegenerative disease. In a recent paper in Neuron, Kim et al. reported that the exercise-induced hormone irisin curbs amyloid-β buildup by promoting secretion of astrocyte-derived neprilysin. These findings may help explain the neuroprotection by irisin and exercise in Alzheimer's disease.

Acute Exercise Effect on Neurocognitive Function Among Cognitively Normal Late-Middle-Aged Adults With/Without Genetic Risk of AD: The Moderating Role of Exercise Volume and APOE Genotype

BACKGROUND

Acute exercise is a behavior that benefits cognitive function; however, its effect on populations with different risks for Alzheimer's disease (AD) and the role of exercise variance and Apolipoprotein E (APOE) genotype on this effect remains unknown. This study explores the acute exercise effect on behavioral and neurocognitive function, and its potential moderation by exercise intensity and duration and APOE genetic risk.

METHODS

Fifty-one cognitively normal adults (~36% APOE ε4 carriers) performed the Stroop task under a rest condition and 3 exercise conditions while electroencephalographic activity was assessed.

RESULTS

Acute exercise improved cognitive performance assessed through both behavioral and neuroelectrical indices. These benefits were observed regardless of adjustments of intensity and duration at a predetermined exercise volume as well as being evident irrespective of APOE ɛ4 carrier status.

CONCLUSIONS

Acute exercise could be proposed as a lifestyle intervention to benefit neurocognitive function in populations with and without genetic risk of AD. Future exploration should further the precise exercise prescription and also the mechanisms underlying the beneficial effects of acute exercise for neurocognitive function.

CLINICAL TRIALS REGISTRATION NUMBER

NCT05591313.

Effects of Exercise Training on Immune-Related Genes and Pathways in the Cortex of Animal Models of Alzheimer's Disease: A Systematic Review

Background

Alzheimer's disease (AD) is a chronic neurodegenerative disease that affects the immune system due to the accumulation of amyloid-β (Aβ) and tau associated molecular pathology and other pathogenic processes. To address AD pathogenesis, various approaches had been conducted from drug development to lifestyle modification to reduce the prevalence of AD. Exercise is considered a prominent lifestyle modification to combat AD.

Objective

This observation prompted us to review the literature on exercise related to immune genes in the cortex of animal models of AD. We focused on animal model studies due to their prevalence in this domain.

Methods

The systematic review was conducted according to PRISMA standards using Web of Science (WoS) and PubMed databases. Any kind of genes, proteins, and molecular molecules were included in this systematic review. The list of these immune-related molecules was analyzed in the STRING database for functional enrichment analysis.

Results

We found that 17 research studies discussed immune-related molecules and 30 immune proteins. These studies showed that exercise had the ability to ameliorate dysfunction in AD-related pathways, which led to decreasing the expression of microglia-related pathways and Th17-related immune pathways. As a result of decreasing the expression of immune-related pathways, the expression of apoptosis-related pathways was also decreasing, and neuronal survival was increased by exercise activity.

Conclusions

Based on functional enrichment analysis, exercise not only could reduce apoptotic factors and immune components but also could increase cell survival and Aβ clearance in cortex samples. PROSPERO ID: CRD42022326093.

Comparative Efficacy, Tolerability, and Acceptability of Donanemab, Lecanemab, Aducanumab, Melatonin, and Aerobic Exercise for a Short Time on Cognitive Function in Mild Cognitive Impairment and Mild Alzheimer's Disease: A Systematic Review and Network Meta-Analysis

Background

The Food and Drug Administration (FDA) has approved lecanemab and aducanumab and is reviewing donanemab, but they have questionable efficacy, serious side effects and are costly, whereas melatonin administration and aerobic exercise for a short time may overcome these problems.

Objective

We aim to compare the efficacy on cognitive function, tolerability and acceptability of melatonin administration and aerobic exercise for a short time with donanemab, lecanemab, and aducanumab in people with mild AD and MCI.

Methods

We systematically reviewed relevant randomized placebo-controlled trials (RCTs) in PubMed, the Cochrane Library, CINHAL, and ClinicalTrials.gov and performed network meta-analyses.

Results

The analysis included 10 randomized placebo-controlled trials with 4,599 patients. Although melatonin and aerobic exercise for a short time were significantly more effective than donanemab, lecanemab, aducanumab and placebo in the primary analysis, there was significant heterogeneity. In the sensitivity analysis excluding exercise, melatonin was significantly more effective than donanemab, lecanemab, aducanumab and placebo, with no significant heterogeneity. Aerobic exercise for a short time was significantly less acceptable than donanemab, aducanumab and placebo. Donanemab, lecanemab, and aducanumab were significantly less tolerable than placebo and donanemab and lecanemab were significantly less acceptable than placebo.

CONCLUSIONS

Melatonin may be a better potential disease-modifying treatment for cognitive decline in mild AD and MCI. Aerobic exercise for a short time might also be better than donanemab, lecanemab and aducanumab if continued, as it is well tolerated and more effective, although less valid due to heterogeneity. Another limitation is the small number of participants.

The Relationship Between Physical Activity and Non-Modifiable Risk Factors on Alzheimer's Disease and Brain Health Markers: A UK Biobank Study

Background

Modifiable (physical activity) and non-modifiable (sex and genotype) risk factors interact to affect Alzheimer's disease (AD) risk. Further investigation is necessary to understand if these factors influence brain volume and cognition.

Objective

The study aimed to assess the effect of physical activity, APOE genotype, and sex on AD risk, brain volume, and cognition.

Methods

UK Biobank data from 2006 to 2023 was accessed. Physical activity was measured by accelerometers, and International Physical Activity Questionnaire. Outcomes were AD incidence; brain volume (ventricular cerebrospinal fluid and total brain); and cognition (executive function, memory, visuospatial ability, processing speed, and reaction time). Logistic and linear regression models were conducted.

Results

69,060 participants met inclusion criteria (mean age: 62.28 years, SD: 7.84; 54.64% female). Higher self-reported (OR = 0.63, 95% CI [0.40, 1.00], p = 0.047) and accelerometer-assessed (OR = 0.96 [0.93, 0.98], p = 0.002) physical activity was associated with lower disease incidence. Smaller ventricular cerebrospinal fluid volume (β= - 65.43 [- 109.68, - 17.40], p = 0.007), and larger total brain volume (β= 4398.46 [165.11, 8631.82], p < 0.001) was associated with increased accelerometer-assessed and self-reported physical activity respectively. Both brain volume analyses were moderated by sex. Increased accelerometer-assessed physical activity levels were associated with faster reaction time (β= - 0.43 [- 0.68, - 0.18], p = 0.001); though poorer visuospatial ability (β= - 0.06 [- 0.09, - 0.03], p < 0.001), and executive function (β= 0.49 [0.31, 0.66], p < 0.001; β= 0.27 [0.10, 0.45], p = 0.002) was related to self-reported physical activity levels.

Conclusions

Higher levels of physical activity reduce AD risk independently of non-modifiable risk factors. Moderation of sex on brain volume highlighted the importance of incorporating non-modifiable risk factors in analysis.

Non-Pharmacological Exercise Randomized Controlled Trials in Alzheimer's Disease

This narrative review aimed to summarize evidence on responses to exercise in pre-clinical Alzheimer's disease (AD) and on how long-term exercise programs work to improve neuropsychiatric symptoms and cognitive performance. We conducted a narrative review of the body of research on the benefits of long-term exercise programs in improving cognitive performance and reducing neuropsychiatric scores in patients with AD. Long-term exercise therapy appears to improve blood flow, increase hippocampal volume, and promote neurogenesis in patients with AD. Higher levels of physical activity are associated with a lower chance of developing the disease, and most prospective studies have shown that physical inactivity is one of the most prevalent modifiable risk factors for the development of AD. Exercise appears to be beneficial in improving cognitive function, a neuropsychiatric symptom of AD. Exercise has been shown to have fewer side effects, such as non-pharmacological effects and better adherence than medication. In this review, experts provided a snapshot and authoritative summary of evidence for non-pharmacological exercise in patients with AD based on the best synthesis efforts, identified the main knowledge gaps and relevant barriers, and provided directions for future research. Furthermore, experts in randomized trial designs provided practical details and recommendations for researchers working in this area, underscoring the importance of relevant topics.

Physical activity, biomarkers of brain pathologies and dementia risk: Results from the Memento clinical cohort

INTRODUCTION

This study aims to examine whether physical activity moderates the association between biomarkers of brain pathologies and dementia risk.

METHODS

From the Memento cohort, we analyzed 1044 patients with mild cognitive impairment, aged 60 and older. Self-reported physical activity was assessed using the International Physical Activity Questionnaire. Biomarkers of brain pathologies comprised medial temporal lobe atrophy (MTA), white matter lesions, and plasma amyloid beta (Aβ)42/40 and phosphorylated tau181. Association between physical activity and risk of developing dementia over 5 years of follow-up, and interactions with biomarkers of brain pathologies were tested.

RESULTS

Physical activity moderated the association between MTA and plasma Aβ42/40 level and increased dementia risk. Compared to participants with low physical activity, associations of both MTA and plasma Aβ42/40 on dementia risk were attenuated in participants with high physical activity.

DISCUSSION

Although reverse causality cannot be excluded, this work suggests that physical activity may contribute to cognitive reserve.

HIGHLIGHTS

Physical activity is an interesting modifiable target for dementia prevention. Physical activity may moderate the impact of brain pathology on dementia risk. Medial temporal lobe atrophy and plasma amyloid beta 42/40 ratio were associated with increased dementia risk especially in those with low level of physical activity.

Comparison of various exercise interventions on cognitive function in Alzheimer's patients: A network meta-analysis

OBJECTIVE

Exercise helps enhance cognitive function in Alzheimer's patients, although the most effective forms of exercise remain unknown.

METHODS

This network meta-analysis was registered in INPLASY (INPLASY202330066). According to predetermined criteria, this investigation comprised randomized controlled studies involving exercise therapies in people with Alzheimer's disease. The exercise intervention was ranked using surface under the cumulative ranking curve (SUCRA) and mean ranking, with the critical goal outcomes being overall cognition, executive function, and memory function.

RESULTS

Resistance exercise is the most likely strategy to be beneficial for slowing down overall cognitive function loss in Alzheimer's patients (72.4%). Additionally, multi-component exercise was the most effective way to improve executive function (30.4%). The only type of exercise that significantly affects memory function is resistance exercise. Memory is the cognitive function that is least responsive to exercise.

CONCLUSION

Resistance exercise may be an efficient intervention for overall cognitive function decline in patients with Alzheimer's and conjointly for their memory function. Multi-component exercise is more effective in improving executive function in patients with Alzheimer's disease.

Aerobic exercise regulates GPR81 signal pathway and mediates complement- microglia axis homeostasis on synaptic protection in the early stage of Alzheimer's disease

AIMS

Memory impairment is a major clinical manifestation in Alzheimer's disease (AD) patients, while regular exercise may prevent and delay degenerative changes in memory functions, and our aim is to explore the influence and molecular mechanisms of aerobic exercise on the early stages of Alzheimer's disease.

MAIN METHODS

3-month-old male APP/PS1 transgenic AD mice and C57BL/6J wild-type mice were randomly divided into four groups: wild-type and APP/PS1 mice with sedentary (WT-SED, AD-SED), and running (WT-RUN, AD-RUN) for 12-weeks. The spatial learning and memory function, RNA-sequencing, spine density, synaptic associated protein, mRNA and protein expression involved in G protein-coupled receptor 81 (GPR81) signaling pathway, and complement factors in brain were measured.

KEY FINDINGS

Aerobic exercise improved spatial learning and memory in APP/PS1 mice, potentially attributed to increased dendritic spine density. Subsequently, potential underlying mechanisms were identified through RNA sequencing: regular aerobic exercise could activate the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) cAMP/PKA signaling pathway and upregulate synaptic function-related proteins to promote synaptic growth, possibly by modulating GPR81. Notably, regular aerobic exercise inhibited microglial activation, reversed the microglial phenotype, reduced the production of initiation factor C1q and central factor C3 in the complement cascade in the brain, prevented the colocalization of microglia and PSD-95, and thus prevented synaptic loss.

SIGNIFICANCE

Physical exercise could play a critical role in improving cognitive function in AD by promoting synaptic growth and preventing synaptic loss, which may be related to the regulation of the GPR81/cAMP/PKA signaling pathway and inhibition of complement-mediated microglial phagocytosis of synapses.

The benefits of rehabilitation exercise in improving chronic traumatic encephalopathy: recent advances and future perspectives

Traumatic encephalopathy syndrome (TES) is used to describe the clinical manifestations of chronic traumatic encephalopathy (CTE). However, effective treatment and prevention strategies are lacking. Increasing evidence has shown that rehabilitation training could prevent cognitive decline, enhance brain plasticity, and effectively improve neurological function in neurodegenerative diseases. Therefore, the mechanisms involved in the effects of rehabilitation exercise therapy on the prognosis of CTE are worth exploring. The aim of this article is to review the pathogenesis of CTE and provide a potential clinical intervention strategy for CTE.

Modulation of microRNAs through Lifestyle Changes in Alzheimer's Disease

Lifestyle factors, including diet and physical activity (PA), are known beneficial strategies to prevent and delay Alzheimer's disease (AD) development. Recently, microRNAs have emerged as potential biomarkers in multiple diseases, including AD. The aim of this review was to analyze the available information on the modulatory effect of lifestyle on microRNA expression in AD. Few studies have addressed this question, leaving important gaps and limitations: (1) in human studies, only circulating microRNAs were analyzed; (2) in mice studies, microRNA expression was only analyzed in brain tissue; (3) a limited number of microRNAs was analyzed; (4) no human nutritional intervention studies were conducted; and (5) PA interventions in humans and mice were poorly detailed and only included aerobic training. Despite this, some conclusions could be drawn. Circulating levels of let-7g-5p, miR-107, and miR-144-3p were associated with overall diet quality in mild cognitive impairment patients. In silico analysis showed that these microRNAs are implicated in synapse formation, microglia activation, amyloid beta accumulation, and pro-inflammatory pathways, the latter also being targeted by miR-129-5p and miR-192-5p, whose circulating levels are modified by PA in AD patients. PA also modifies miR-132, miR-15b-5p, miR-148b-3p, and miR-130a-5p expression in mice brains, which targets are related to the regulation of neuronal activity, ageing, and pro-inflammatory pathways. This supports the need to further explore lifestyle-related miRNA changes in AD, both as biomarkers and therapeutic targets.

Effects of Exercise on Quality of Life in Subjects with Alzheimer's Disease: Systematic Review with Meta-Analysis of Randomized Clinical Trials

Alzheimer's disease is a type of dementia that progressively affects memory, thinking, and behavior. It can interfere with daily activities and lead to a decline in cognitive abilities over time. Exercise-based interventions can complement Alzheimer's disease treatment. Exercise is a valuable tool in all healthcare settings and has shown promise as an effective cognitive improvement intervention for people with cognitive impairments. This systematic review and meta-analysis aimed to analyze the effect of physical exercise on the QoL of subjects with Alzheimer's disease. A search was performed with the help of the electronic databases PubMed and Web of Science. Randomized controlled trials with exercise-based interventions were selected. Four studies met the inclusion criteria, which included interventions based on exercise. The effects were summarized using standardized mean differences (95% confidence intervals) using random-effect models. The results showed that exercise had no significant effect on the QoL of subjects with Alzheimer. Thus, the effect of exercise interventions on the QoL of patients with Alzheimer's disease is not conclusive. More research is needed about this topic and the way in which the QoL is assessed; the necessity to conduct an objective way to assess the QoL in this population is mandatory.

Qualitative research concerning physiotherapy approaches to encourage physical activity in older adults with dementia

BACKGROUND

Physical exercise is known to improve the level of activities of daily living and physical function in people with dementia; however, symptoms of dementia often pose challenges when implementing physical therapy. This study aimed to elucidate how physiotherapists (PTs) engage with older adults with dementia to encourage exercise and participation in physical activity.

METHODS

In this qualitative study, four PTs working with older adults with dementia in long-term care facilities in Japan were recruited and interviewed. We used a modified grounded theory approach to assess how PTs engaged with older adults with dementia during physiotherapy sessions.

RESULTS

Based on PT responses, five categories of engagement were identified: "make structured preparations for clients to begin physical activity," "link exercise therapy to a client's daily life," "discover changes in daily life," "ascertain cognitive function," and "accommodate client differences." Concepts were derived under each category. The category "make structured preparations for clients to begin physical activity" served as a preceding stage for PTs to engage with older adults with dementia. PTs linked exercise therapy to each client's daily life activities to encourage voluntary participation in daily physical activity. PTs ensured the performance of routine patterns of movement and modified these movement patterns per clients' differing paces.

CONCLUSION

PTs provided exercise and movement training based on various degrees of client involvement and made structured preparations for clients to begin physical activity that were linked to exercise therapy. Our findings may prompt PTs to encourage older people with dementia to participate in physical therapy and benefit from exercise.

The Efficacy and Safety of Physiotherapy in People with Dementia: A Systematic Review

BACKGROUND

Physiotherapy has become increasingly relevant as a new therapeutic intervention for dementia. However, it is unclear which interventions are the most suitable.

OBJECTIVE

This study sought to summarize and critically appraise the evidence on physiotherapy interventions in dementia.

METHODS

A systematic review conducted using CENTRAL, MEDLINE, and PEDro databases, from their inception to July 2022, identified all experimental studies of dementia that included physiotherapy interventions.

RESULTS

Of 194 articles included, the most frequently used interventions were aerobic training (n = 82, 42%), strength training (n = 79, 41%), balance training (n = 48, 25%), and stretching (n = 22, 11%). These were associated with a positive effect on several motor and cognitive outcomes. A total number of 1,119 adverse events were reported.

CONCLUSION

Physiotherapy has several motor and cognitive benefits in dementia. Future research should focus on establishing a physiotherapy prescription protocol for people with mild cognitive impairment and for each stage of dementia.

Effects of exercise interventions in Alzheimer's disease: A meta-analysis

OBJECTIVE

The aim of this study was to investigate the clinical efficacy of exercise intervention in the treatment of patients with Alzheimer's disease (AD) by meta-analysis.

METHODS

From January 2000 to January 2022, PubMed, Web of Science, Embase, CNKI, and WanFang databases were searched for all studies on the clinical efficacy of exercise intervention in the treatment of AD patients. Stata 17.0 statistical software was used for meta-analysis.

RESULTS

Specifically, data of 983 patients were subjected to meta-analysis, including 463 patients in the control group (conventional drug therapy) and 520 patients in the treatment group (physical exercise on the basis of conventional therapy). The results of meta-analysis showed that Mini-Mental State Examination (MMSE) score and Activities of Daily Living Scale (ADL) score in the treatment group were significantly higher than those in the control group. Further subgroup analysis of exercise intervention >16 weeks found that MMSE and ADL scores in the treatment group were significantly higher than those in the control group. Subgroup analysis of exercise intervention ≤16 weeks demonstrated that MMSE and ADL in the treatment group were higher than those in the control group. In addition, the treatment group had a significant lower Neuropsychiatric Inventory (NPI) score compared with the control group (SMD = -0.76, 95% CI (-1.37, -0.16), p = .013); subgroup analysis showed that the NPI score in the treatment group were lower than that in the control group when exercise intervention was >16 weeks [SMD = -1.01, 95% CI (-1.99, -0.04), p = .042] and ≤16 weeks [SMD = 0.43, 95% CI (-0.82, -0.03), p = .034].

CONCLUSION

Exercise intervention can improve the neuropsychiatric symptoms, activities of daily living and cognitive function of AD patients, but the improvement is not significant in case of exercise intervention ≤16 weeks.

Applying person-centered research ethics in the design of dementia-specific measures

There is an emerging call for new strengths-based measures to guide research, care, and support for persons living with Alzheimer's disease and related dementias. Person-centered interventions have demonstrated a positive impact in global quality of life, but many promising approaches lack strengths-based measures with sufficient sensitivity to document relevant outcomes. Human centered design is an innovative method for person-centered instrument development. This paper describes a research process using Human Centered Design and highlights ethical principles considered during the translation of the design process to experiential world of Alzheimer's disease and related dementia. Including persons living with dementia and care partners as members of the design team offers new insights, while requiring focused attention on inclusivity, transparency, and person-centered ethics.