Multicomponent Training Prevents Memory Deficit Related to Amyloid-β Protein-Induced Neurotoxicity

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.

Effect of Multicomponent Exercise on Cognition, Physical Function and Activities of Daily Life in Older Adults With Dementia or Mild Cognitive Impairment: A Systematic Review and Meta-analysis

OBJECTIVE

To review the evidence for the effectiveness of multicomponent exercise (an exercise program combining aerobic, endurance, balance, and flexibility exercises) on cognition, physical function, and activities of daily living in people with dementia and mild cognitive impairment (MCI).

DATA SOURCES AND STUDY SELECTION

We conducted this study under the guidance of a designated protocol (PROSPERO CRD42022324641). Pertinent randomized controlled trials were selected from PubMed, Embase, Web of Science, and the Cochrane Library by 2 independent authors through May 2022.

DATA EXTRACTION

Two authors independently extracted the data and assessed the quality of the included studies following the Cochrane Risk of Bias tool. Outcome data were extracted in a random effects model and estimated as Hedges' g and 95% confidence interval (CI). To validate specific results, the Egger test combined the Duval and Tweedie "trim and fill" method and sensitivity analysis with study removed were performed.

DATA SYNTHESIS

A total of 21 publications were eligible for the quantitative analysis. In dementia, estimates of Hedges' g showed effects on global cognition (g=0.403; 95% CI, 0.168-0.638; P<.05), especially executive function (g=0.344; 95% CI, 0.111-0.577; P<.05), flexibility (g=0.671; 95% CI, 0.353-0.989; P<.001), agility and mobility (g=0.402; 95% CI, 0.089-0.714; P<.05), muscle strength (g=1.132; 95% CI, 0.420-1.845; P<.05), and activities of daily living (g=0.402; 95% CI, 0.188-0.615; P<.05). Also, a positive trend was observed in gait speed. Additionally, multicomponent exercise had positive effects on global cognition (g=0.978; 95% CI, 0.298-1.659; P<.05) and executive function (g=0.448; 95% CI, 0.171-0.726; P<.05) in patients with MCI.

CONCLUSIONS

Our findings confirm the viability of multicomponent exercise as a management strategy for patients with dementia and MCI.

Analysis of factors related to cognitive impairment in a community-based, complete enumeration survey in Japan: the Nakayama study

BACKGROUND

The number of patients with cognitive disorders is rapidly increasing in the world, becoming not only a medical problem, but also a social problem. There have been many reports that various factors are associated with cognitive dysfunction, but the factors have not yet been fully identified. This was a community-based complete enumeration study which aimed to identify risk and protective factors for dementia.

METHODS

The first phase included all residents aged 65 years or older in a town in Japan. They completed many examinations, such as living conditions questionnaires, physical examination, Mini-Mental State Examination, and brain magnetic resonance imaging. The participants with suspected cognitive impairment underwent additional examinations for detailed evaluation in the second phase. Statistical analysis was performed to identify risk and protective factors for dementia after all participants were diagnosed.

RESULTS

There were 927 participants in the baseline evaluation; 611 (65.9%) were healthy, 165 (17.8%) had mild cognitive impairment (MCI), and 151 (16.3%) had dementia. The age-standardised prevalence of dementia was 9.5%. Statistical analyses for amnestic MCI and Alzheimer's disease showed that risk factors for cognitive decline were diabetes mellitus, low activities of daily living, and living alone, and that protective factors were history of exercise and drinking habit.

CONCLUSION

The present findings suggest that several lifestyle-related diseases and factors are associated with cognitive decline. These results support similar findings from previous studies and will be helpful for preventing dementia in the future.

Does Preoperative Cognitive Optimization Improve Postoperative Outcomes in the Elderly?

Perioperative neurocognitive disorder (PND) is a growing concern, affecting several million elderly patients each year in the United States, but strategies for its effective prevention have not yet been established. Humeidan et al. recently demonstrated that preoperative brain exercise resulted in a decrease in postoperative delirium incidence in elderly surgical patients, suggesting the potential of presurgical cognitive optimization to improve postoperative cognitive outcomes. This brief review summarizes the current knowledge regarding preoperative cognitive optimization and highlights landmark studies, as well as current ongoing studies, as the field is rapidly growing. This review further discusses the benefit of cognitive training in non-surgical elderly populations and the role of cognitive training in patients with preexisting cognitive impairment or dementia. The review also examines preclinical evidence in support of cognitive training, which can facilitate understanding of brain plasticity and the pathophysiology of PND. The literature suggests positive impacts of presurgical cognitive optimization, but further studies are encouraged to establish effective cognitive training programs for elderly presurgical patients.

Concurrent exercise does not prevent recognition memory deficits induced by beta-amyloid in rats

Alzheimer's disease affects thousands of people worldwide. Alternatives aiming to prevent the disease or reduce its symptoms include different physical exercise configurations. Here we investigate the potential of concurrent exercise to prevent recognition memory deficits in an Alzheimer's disease-like model induced by the hippocampal beta-amyloid (Aβ) injection in Wistar rats. We demonstrate that the concurrent exercise, which included running and strength exercises performed in the same exercise session, is ineffective in preventing recognition memory deficits in the Aβ rats. Besides, higher levels of reactive oxygen species were found in the concurrent exercise group's hippocampus. The running exercise administrated alone prevented recognition memory impairments.