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British Journal of Sports Medicine Jun 2022Physical activity (PA) is associated with a decreased incidence of dementia, but much of the evidence comes from short follow-ups prone to reverse causation. This... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Physical activity (PA) is associated with a decreased incidence of dementia, but much of the evidence comes from short follow-ups prone to reverse causation. This meta-analysis investigates the effect of study length on the association.
DESIGN
A systematic review and meta-analysis. Pooled effect sizes, dose-response analysis and funnel plots were used to synthesise the results.
DATA SOURCES
CINAHL (last search 19 October 2021), PsycInfo, Scopus, PubMed, Web of Science (21 October 2021) and SPORTDiscus (26 October 2021).
ELIGIBILITY CRITERIA
Studies of adults with a prospective follow-up of at least 1 year, a valid cognitive measure or cohort in mid-life at baseline and an estimate of the association between baseline PA and follow-up all-cause dementia, Alzheimer's disease or vascular dementia were included (n=58).
RESULTS
PA was associated with a decreased risk of all-cause dementia (pooled relative risk 0.80, 95% CI 0.77 to 0.84, n=257 983), Alzheimer's disease (0.86, 95% CI 0.80 to 0.93, n=128 261) and vascular dementia (0.79, 95% CI 0.66 to 0.95, n=33 870), even in longer follow-ups (≥20 years) for all-cause dementia and Alzheimer's disease. Neither baseline age, follow-up length nor study quality significantly moderated the associations. Dose-response meta-analyses revealed significant linear, spline and quadratic trends within estimates for all-cause dementia incidence, but only a significant spline trend for Alzheimer's disease. Funnel plots showed possible publication bias for all-cause dementia and Alzheimer's disease.
CONCLUSION
PA was associated with lower incidence of all-cause dementia and Alzheimer's disease, even in longer follow-ups, supporting PA as a modifiable protective lifestyle factor, even after reducing the effects of reverse causation.
Topics: Alzheimer Disease; Dementia, Vascular; Disease Progression; Exercise; Humans; Prospective Studies; Protective Factors
PubMed: 35301183
DOI: 10.1136/bjsports-2021-104981 -
Journal of Sleep Research Aug 2021Suboptimal sleep causes cognitive decline and probably accelerates Alzheimer's Disease (AD) progression. Several sleep interventions have been tested in established AD... (Review)
Review
Suboptimal sleep causes cognitive decline and probably accelerates Alzheimer's Disease (AD) progression. Several sleep interventions have been tested in established AD dementia cases. However early intervention is needed in the course of AD at Mild Cognitive Impairment (MCI) or mild dementia stages to help prevent decline and maintain good quality of life. This systematic review aims to summarize evidence on sleep interventions in MCI and mild AD dementia. Seven databases were systematically searched for interventional studies where ≥ 75% of participants met diagnostic criteria for MCI/mild AD dementia, with a control group and validated sleep outcome measures. Studies with a majority of participants diagnosed with Moderate to Severe AD were excluded. After removal of duplicates, 22,133 references were returned in two separate searches (August 2019 and September 2020). 325 full papers were reviewed with 18 retained. Included papers reported 16 separate studies, total sample (n = 1,056), mean age 73.5 years. 13 interventions were represented: Cognitive Behavioural Therapy - Insomnia (CBT-I), A Multi-Component Group Based Therapy, A Structured Limbs Exercise Programme, Aromatherapy, Phase Locked Loop Acoustic Stimulation, Transcranial Stimulation, Suvorexant, Melatonin, Donepezil, Galantamine, Rivastigmine, Tetrahydroaminoacridine and Continuous Positive Airway Pressure (CPAP). Psychotherapeutic approaches utilising adapted CBT-I and a Structured Limbs Exercise Programme each achieved statistically significant improvements in the Pittsburgh Sleep Quality Index with one study reporting co-existent improved actigraphy variables. Suvorexant significantly increased Total Sleep Time and Sleep Efficiency whilst reducing Wake After Sleep Onset time. Transcranial Stimulation enhanced cortical slow oscillations and spindle power during daytime naps. Melatonin significantly reduced sleep latency in two small studies and sleep to wakefulness transitions in a small sample. CPAP demonstrated efficacy in participants with Obstructive Sleep Apnoea. Evidence to support other interventions was limited. Whilst new evidence is emerging, there remains a paucity of evidence for sleep interventions in MCI and mild AD highlighting a pressing need for high quality experimental studies exploring alternative sleep interventions.
Topics: Alzheimer Disease; Cognitive Dysfunction; Humans; Quality of Life; Sleep
PubMed: 33289311
DOI: 10.1111/jsr.13229 -
Alzheimer's Research & Therapy Mar 2023The use of music interventions as a non-pharmacological therapy to improve cognitive and behavioral symptoms in Alzheimer's disease (AD) patients has gained popularity... (Review)
Review
BACKGROUND
The use of music interventions as a non-pharmacological therapy to improve cognitive and behavioral symptoms in Alzheimer's disease (AD) patients has gained popularity in recent years, but the evidence for their effectiveness remains inconsistent.
OBJECTIVES
To summarize the evidence of the effect of music therapy (alone or in combination with pharmacological therapies) on cognitive functions in AD patients compared to those without the intervention.
METHODS
A systematic literature search was performed in PubMed, Cochrane library, and HINARI for papers published from 1 January 2012 to 25 June 2022. All randomized controlled trials that compared music therapy with standard care or other non-musical intervention and evaluation of cognitive functions are included. Cognitive outcomes included: global cognition, memory, language, speed of information processing, verbal fluency, and attention. Quality assessment and narrative synthesis of the studies were performed.
RESULTS
A total of 8 studies out of 144 met the inclusion criteria (689 participants, mean age range 60.47-87.1). Of the total studies, 4 were conducted in Europe (2 in France, 2 in Spain), 3 in Asia (2 in China, 1 in Japan), and 1 in the USA. Quality assessment of the retrieved studies revealed that 6 out of 8 studies were of high quality. The results showed that compared to different control groups, there is an improvement in cognitive functions after music therapy application. A greater effect was shown when patients are involved in the music making when using active music intervention (AMI).
CONCLUSION
The results of this review highlight the potential benefits of music therapy as a complementary treatment option for individuals with AD and the importance of continued investigation in this field. More research is needed to fully understand the effects of music therapy, to determine the optimal intervention strategy, and to assess the long-term effects of music therapy on cognitive functions.
Topics: Aged; Aged, 80 and over; Humans; Middle Aged; Alzheimer Disease; Cognition; Music; Music Therapy; Randomized Controlled Trials as Topic
PubMed: 36973733
DOI: 10.1186/s13195-023-01214-9 -
Ageing Research Reviews Dec 2021To assess the potential multi-domain benefits of exercise interventions on patients with Alzheimer's disease (AD), as well as to determine the specific effects of... (Meta-Analysis)
Meta-Analysis Review
AIMS
To assess the potential multi-domain benefits of exercise interventions on patients with Alzheimer's disease (AD), as well as to determine the specific effects of different exercise modalities (aerobic, strength, or combined training).
METHODS
A systematic search was conducted in PubMed and Web of Science until March 2021 for randomized controlled trials assessing the effect of exercise interventions (compared with no exercise) on patients with AD. Outcomes included cognitive function (mini-mental state examination [MMSE] test), physical function (e.g., 6-minute walking test [6MWT]), functional independence (Barthel index), and neuropsychiatric symptoms (Neuropsychiatric Inventory [NPI]). A random-effects meta-analysis was conducted.
RESULTS
28 studies (total n = 1337 participants, average age 79-90 years) were included in the systematic review, of which 21 could be meta-analyzed. Although considerable heterogeneity was found, exercise interventions induced several significant benefits, including in Barthel index (n = 147 patients, mean difference [MD]=8.36 points, 95% confidence interval [CI]=0.63-16.09), 6MWT (n = 369, MD=84 m, 95% CI=44-133)), and NPI (n = 263, MD=-4.4 points, 95% CI=-8.42 to -0.38). Benefits were also found in the MMSE test, albeit significance was only reached for aerobic exercise (n = 187, MD=2.31 points, 95% CI 0.45-4.27).
CONCLUSIONS
Exercise interventions appear to exert multi-domain benefits in patients with AD.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Cognition; Exercise; Exercise Therapy; Humans; Quality of Life; Randomized Controlled Trials as Topic
PubMed: 34601135
DOI: 10.1016/j.arr.2021.101479 -
International Journal of Environmental... Sep 2021The hypothesis of an infectious connection from the oro-pharyngeal sphere to the brain underlines the interest in analyzing the link between periodontal disease and... (Review)
Review
The hypothesis of an infectious connection from the oro-pharyngeal sphere to the brain underlines the interest in analyzing the link between periodontal disease and Alzheimer's disease. The aim of this systematic review was to examine the link between Alzheimer's disease and periodontal disease in patients aged 65 and over. Databases (PubMed (MEDLINE), the Cochrane Library, and Embase) were analyzed for relevant references up to 21 June 2021. The authors independently selected the studies and extracted the data. The quality of included studies was checked using the National Institutes of Health's quality assessment tools. Five studies were included. The selected studies described in their results an increase in in Alzheimer's disease patients (adjusted = 0.02), and its incidence was linked to and (adjusted HR = 1.22 (1.04-1.43), = 0.012) as well as (crude HR = 2.0 (1.1-3.8)). The presence of periodontitis at baseline was associated with a six-fold increase in the rate of cognitive decline over a 6-month follow-up period (ADAS-Cog mean change = 2.9 ± 6.6). The current review suggests an association between periodontal disease and Alzheimer's disease. The treatment of periodontal disease could be a way to explore Alzheimer's disease prevention.
Topics: Alzheimer Disease; Brain; Cognitive Dysfunction; Humans; Periodontal Diseases; Periodontitis
PubMed: 34501899
DOI: 10.3390/ijerph18179312 -
Journal of Alzheimer's Disease : JAD 2020Dementia is a severe neurodegenerative disorder and it can be categorized into several subtypes by different pathogenic causes. We sought to comprehensively analyzed the... (Meta-Analysis)
Meta-Analysis
Dementia is a severe neurodegenerative disorder and it can be categorized into several subtypes by different pathogenic causes. We sought to comprehensively analyzed the prevalence of dementia from perspectives of geographic region (Asia, Africa, South America, and Europe/North America), age, and gender. We searched PubMed and EMBASE for relevant articles on dementia published from January 1985 to August 2019. In these studies, analyses were stratified by geographic region, age, and gender. Meta-regression was conducted to identify if there were significant differences between groups. We included forty-seven studies. Among the individuals aged 50 and over in the community, the pooled prevalence for all-cause dementia, Alzheimer's disease, and vascular dementia were 697 (CI95%: 546-864) per 10,000 persons, 324 (CI95%: 228-460) per 10,000 persons, and 116 (CI95%: 86-157) per 10,000 persons, respectively. In our study, the prevalence of all-type dementia in individuals aged 100 years and older (6,592 per 10,000 cases) is 244 times higher than in those aged 50-59 (27 per 10,000 cases). The number of people living with dementia approximately doubles every five years. The prevalence was greater in women than in men (788 cases versus 561 cases per 10,000 persons) in overall analysis. In individuals aged 60 to 69 years, AD prevalence in females was 1.9 times greater than that in males (108 cases versus 56 cases per 10,000 persons), while the prevalence of VaD was 1.8 times greater in males than in females (56 cases versus 32 cases per 10,000 persons). Prevalence rate was higher in Europe and North America than in Asia, Africa, and South America.
Topics: Africa; Age Factors; Alzheimer Disease; Dementia; Dementia, Vascular; Europe; Humans; North America; Prevalence; Sex Factors
PubMed: 31884487
DOI: 10.3233/JAD-191092 -
Ageing Research Reviews Aug 2022Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique. When stimulation is applied over the primary motor cortex and coupled with... (Meta-Analysis)
Meta-Analysis Review
Cortical excitability and plasticity in Alzheimer's disease and mild cognitive impairment: A systematic review and meta-analysis of transcranial magnetic stimulation studies.
BACKGROUND
Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique. When stimulation is applied over the primary motor cortex and coupled with electromyography measures, TMS can probe functions of cortical excitability and plasticity in vivo. The purpose of this meta-analysis is to evaluate the utility of TMS-derived measures for differentiating patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) from cognitively normal older adults (CN).
METHODS
Databases searched included PubMed, Embase, APA PsycInfo, Medline, and CINAHL Plus from inception to July 2021.
RESULTS
Sixty-one studies with a total of 2728 participants (1454 patients with AD, 163 patients with MCI, and 1111 CN) were included. Patients with AD showed significantly higher cortical excitability, lower cortical inhibition, and impaired cortical plasticity compared to the CN cohorts. Patients with MCI exhibited increased cortical excitability and reduced plasticity compared to the CN cohort. Additionally, lower cognitive performance was significantly associated with higher cortical excitability and lower inhibition. No seizure events due to TMS were reported, and the mild adverse response rate is approximately 3/1000 (i.e., 9/2728).
CONCLUSIONS
Findings of our meta-analysis demonstrate the potential of using TMS-derived cortical excitability and plasticity measures as diagnostic biomarkers and therapeutic targets for AD and MCI.
Topics: Aged; Alzheimer Disease; Cognitive Dysfunction; Cortical Excitability; Humans; Neuronal Plasticity; Transcranial Magnetic Stimulation
PubMed: 35680080
DOI: 10.1016/j.arr.2022.101660 -
International Journal of Environmental... Nov 2022A growing body of research has examined the effect of aerobic exercise on cognitive function in people with Alzheimer's Disease (AD), but the findings of the available... (Meta-Analysis)
Meta-Analysis Review
A growing body of research has examined the effect of aerobic exercise on cognitive function in people with Alzheimer's Disease (AD), but the findings of the available studies were conflicting. The aim of this study was to explore the effect of aerobic exercise on cognitive function in AD patients. Searches were performed in PubMed, Web of Science, and EBSCO databases from the inception of indexing until 12 November 2021. Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. From 1942 search records initially identified, 15 randomized controlled trials (RCTs) were considered eligible for systematic review and meta-analysis. Included studies involved 503 participants in 16 exercise groups (mean age: 69.2-84 years) and 406 participants (mean age: 68.9-84 years) in 15 control groups. There was a significant effect of aerobic exercise on increasing mini-mental state examination (MMSE) score in AD patients [weighted mean difference (WMD), 1.50 (95% CI, 0.55 to 2.45), = 0.002]. Subgroup analyses showed that interventions conducted 30 min per session [WMD, 2.52 (95% CI, 0.84 to 4.20), = 0.003], less than 150 min per week [WMD, 2.10 (95% CI, 0.84 to 3.37), = 0.001], and up to three times per week [WMD, 1.68 (95% CI, 0.46 to 2.89), = 0.007] increased MMSE score significantly. In addition, a worse basal cognitive status was associated with greater improvement in MMSE score. Our analysis indicated that aerobic exercise, especially conducted 30 min per session, less than 150 min per week, and up to three times per week, contributed to improving cognitive function in AD patients. Additionally, a worse basal cognitive status contributed to more significant improvements in cognitive function.
Topics: Humans; Aged; Aged, 80 and over; Alzheimer Disease; Randomized Controlled Trials as Topic; Cognition; Exercise
PubMed: 36497772
DOI: 10.3390/ijerph192315700 -
European Journal of Preventive... May 2022As the potential impact of statins on cognitive decline and dementia is still debated, we conducted a meta-analysis of observational studies to examine the effect of... (Meta-Analysis)
Meta-Analysis
AIMS
As the potential impact of statins on cognitive decline and dementia is still debated, we conducted a meta-analysis of observational studies to examine the effect of statin use on the risk of Alzheimer's disease (AD) and dementia.
METHODS AND RESULTS
PubMed, Cochrane, and EMBASE were searched since inception to January 2021. Inclusion criteria were: (i) cohort or case-control studies; (ii) statin users compared to non-users; and (iii) AD and/or dementia risk as outcome. Estimates from original studies were pooled using restricted maximum-likelihood random-effect model. Measure of effects were reported as odds ratio (OR) and 95% confidence intervals (CIs). In the pooled analyses, statins were associated with a decreased risk of dementia [36 studies, OR 0.80 (CI 0.75-0.86)] and of AD [21 studies, OR 0.68 (CI 0.56-0.81)]. In the stratified analysis by sex, no difference was observed in the risk reduction of dementia between men [OR 0.86 (CI 0.81-0.92)] and women [OR 0.86 (CI 0.81-0.92)]. Similar risks were observed for lipophilic and hydrophilic statins for both dementia and AD, while high-potency statins showed a 20% reduction of dementia risk compared with a 16% risk reduction associated with low-potency statins, suggesting a greater efficacy of the former, although a borderline statistical significance (P = 0.05) for the heterogeneity between estimates.
CONCLUSION
These results confirm the absence of a neurocognitive risk associated with statin treatment and suggest a potential favourable role of statins. Randomized clinical trials with an ad hoc design are needed to explore this potential neuroprotective effect.
Topics: Alzheimer Disease; Cognitive Dysfunction; Dementia; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Odds Ratio
PubMed: 34871380
DOI: 10.1093/eurjpc/zwab208 -
Ageing Research Reviews Sep 2021Alterations in olfactory functions are proposed to be early biomarkers for neurodegeneration. Many neurodegenerative diseases are age-related, including two of the most... (Review)
Review
Alterations in olfactory functions are proposed to be early biomarkers for neurodegeneration. Many neurodegenerative diseases are age-related, including two of the most common, Parkinson's disease (PD) and Alzheimer's disease (AD). The establishment of biomarkers that promote early risk identification is critical for the implementation of early treatment to postpone or avert pathological development. Olfactory dysfunction (OD) is seen in 90% of early-stage PD patients and 85% of patients with early-stage AD, which makes it an attractive biomarker for early diagnosis of these diseases. Here, we systematically review widely applied smelling tests available for humans as well as olfaction assessments performed in some animal models and the relationships between OD and normal aging, PD, AD, and other conditions. The utility of OD as a biomarker for neurodegenerative disease diagnosis and future research directions are also discussed.
Topics: Aging; Alzheimer Disease; Animals; Humans; Neurodegenerative Diseases; Olfaction Disorders; Parkinson Disease; Smell
PubMed: 34325072
DOI: 10.1016/j.arr.2021.101416