Tai chi for mild cognitive impairment: a systematic review

Effectiveness of Tai Chi on cognitive function among older adults with mild cognitive impairment: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effectiveness of Tai Chi on cognitive function in older adults with mild cognitive impairment.

METHODS

A systematic search of eight English and five Chinese electronic databases was conducted to identify randomized controlled trials of Tai Chi as the intervention. The main outcomes included executive function, episodic memory, visuospatial function, working memory, concentration, memory complaints, and global cognition. The Cochrane RoB tool was used to assess bias in the study. Meta-analysis was conducted using Review Manager 5.4. Narrative syntheses were performed if meta-analysis was inappropriate.

RESULTS

A total of eleven trials (905 participants) were included. Meta-analysis showed that Tai Chi significantly and moderately affected executive function (SMD = -1.01, 95% CI: -1.54 to -0.47, p < 0.001), episodic memory (SMD = 0.59, 95% CI: 0.24 to 0.94, p = 0.001), visuospatial function (SMD = 0.38, 95% CI: 0.15 to 0.60, p < 0.001), and global cognition (SMD = 0.57, 95% CI: 0.14 to 1.00, p = 0.01).One study showed that Tai Chi could improve verbal fluency.

CONCLUSIONS

This review reveals that Tai Chi can improve executive function, episodic memory, visuospatial function, and global cognition in older adults with mild cognitive impairment, but not working memory, concentration, or memory complaints. These findings are consist with existing reviews about the effectiveness of Tai Chi. Long-duration (> 1500 min) Tai Chi is more effective for improving global cognition. However, the findings should be interpreted with caution due to the potential risk of bias and limited sample sizes of the included studies. Future trials should examine the effectiveness of standardized Tai Chi intervention on cognitive outcomes in older adults with mild cognitive impairment.

Effects and mechanisms of Tai Chi on mild cognitive impairment and early-stage dementia: a scoping review

BACKGROUND

Dementia is associated with cognitive and functional decline that significantly impacts quality of life. There is currently no cure for dementia, thus, it is important to manage dementia in the early stages and delay deterioration. Previous studies have documented a range of health benefits of Tai Chi in people with early-stage dementia, however, none have systematically integrated these effects with their underlying mechanisms. The aims of this study were to (1) identify the neurocognitive, psychological, and physical health benefits of Tai Chi oi people with early-stage dementia, and (2) explore the underlying mechanisms of these effects.

METHODS

We searched systematic reviews (SRs) and randomised control trials (RCTs) on Tai Chi for adults aged 50 years and older with mild cognitive impairment (MCI) or early-stage dementia in MEDLINE, PubMed, Cochrane Library, EMBASE, and major Chinese databases. No language or publication restrictions were applied. Risk of bias was assessed.

RESULTS

Eight SRs with meta-analyses and 6 additional published RCTs revealed inconsistent findings of Tai Chi on improving global cognitive function, attention and executive function, memory and language, and perceptual-motor function. There was no significant between-group difference in depressive symptoms. The results from the RCTs showed that Tai Chi can reduce arthritis pain and slow the progress of dementia. No studies on MCI or early-stage dementia investigating the underlying mechanisms of Tai Chi were identified. Instead, nine mechanistic studies on healthy adults were included. These suggested that Tai Chi may improve memory and cognition via increased regional brain activity, large-scale network functional connectivity, and regional grey matter volume.

CONCLUSION

The effects of Tai Chi on neurocognitive outcomes in people with MCI and early-stage dementia are still inconclusive. Further high-quality clinical trials and mechanistic studies are needed to understand if and how Tai Chi may be applied as a successful intervention to delay deterioration and improve the quality of life in people with an increased risk of cognitive decline.

Effects of mind-body exercise Baduanjin on cognition in community-dwelling older people with mild cognitive impairment: A randomized controlled trial

OBJECTIVE

To determine the effect of a 6-month traditional Chinese mind-body Baduanjin exercise intervention on cognitive ability in older people with Mild cognitive impairment (MCI).

METHODS

A total of 135 community-dwelling seniors with MCI were randomized into either the Baduanjin group (BDJ), the brisk walking group (BWK) or the usual physical activity control group (UPA). Cognitive ability was assessed at baseline, 2, 4 and 6 months post-intervention, and 3 months after the intervention ended.

RESULTS

After 6 months of intervention, the MoCA score of the BDJ group was significantly higher than that of the UPA group (P < 0.05), The Go/No-go correct numbers of the BDJ group and BWK group were significantly higher than those of the UPA group (P < 0.05). There was no statistical difference in other outcomes, or there were only a tiny effect size. Three months after the intervention, there was no significant difference between the primary and secondary outcomes(P > 0.05).

CONCLUSION

The 6-month period of Baduanjin training has positive benefits on global cognitive function and attention function in community-dwelling elderly individuals with MCI. The effect seems to have been transient and needs to be confirmed by additional studies.

Effects of Tai Chi combined with tDCS on cognitive function in patients with MCI: a randomized controlled trial

Background

Mild cognitive impairment (MCI) is a critical stage of dementia. Previous reviews have suggested that physical exercise combined with non-invasive brain stimulation is more beneficial for improving cognitive function. However, no targeted studies have confirmed the effect of Tai Chi combined with transcranial direct current stimulation (tDCS) on the improvement of cognitive function in patients with MCI. Thus, this randomized trial was conducted to assess the effect of Tai Chi combined with tDCS on the cognitive performance of patients with MCI.

Methods

From April 2018 to February 2020, a randomized, single-blind clinical trial was conducted, involving 180 participants with MCI who were divided into four intervention groups: Tai Chi combined with tDCS (TCT), Tai Chi combined with sham tDCS (TCS), walking combined with tDCS (WAT), and walking combined with sham tDCS (WAS). All participants were assessed at baseline and 12 weeks for global cognitive function, memory, attention, and executive function.

Results

At baseline, there were no significant differences in age, gender, education duration, body mass index, or the Baker Depression Inventory among the four groups (P ≥ 0.05). After 12 weeks of intervention, the TCT group showed greater improvements in MOCA scores, memory quotient scores, and digit-symbol coding task reaction time compared to the TCS, WAS, and WAT groups (P < 0.05). The TCT group also had a shorter Stroop test color reaction time compared to the WAS and WAT groups (P < 0.05), a higher increase in Auditory Verbal Learning Test-immediate recall than the TCS and WAT groups (P < 0.05), a shorter visual reaction time than the TCS group (P < 0.05), and a shorter sustained attention time compared to the WAT group (P < 0.05).

Conclusion

Tai Chi combined with tDCS effectively improves global cognitive performance, memory, execution function, and attention in patients with MCI. These findings suggest the potential clinical use of Tai Chi combined with tDCS as a physical exercise combined with a non-invasive brain stimulation intervention to improve cognitive function in older adults with MCI.

Clinical trial registration

ChiCTR1800015629.

Effects of traditional Chinese mind–body exercises on older adults with cognitive impairment: A systematic review and meta-analysis

Objective

To determine the effectiveness of traditional Chinese mind–body exercises in improving cognition, memory, and executive function in older adults with cognitive impairment.

Data sources

Relevant English and Chinese language studies published until September 14th, 2022 were retrieved from PubMed, Web of Science, Cochrane Library, Embase, CINAHL, WAN FANG DATA, VIP Information, CNKI, and SinoMed databases.

Review methods

Randomized controlled trials assessing traditional Chinese mind–body exercises (Tai Chi, Baduanjin, Qigong, Mind–Body Therapies, and Yijinjing) in older adults with cognitive impairment were included. Two researchers independently identified eligible studies and extracted data. A risk-of-bias assessment was performed using the Cochrane Risk of Bias Tool.

Results

This study included 15 randomized controlled trials (1,127 participants) from China, Thailand and American. Most studies had a high risk of bias in the blinding of participants and researchers, one study had a high risk of bias in the random sequence generation and two studies had a high risk of bias in the incomplete outcome data. Compared with conventional therapy alone, traditional Chinese mind–body exercises significantly improved global cognitive function (p &lt; 0.00001), and Baduanjin could improve the global cognitive function (p &lt; 0.00001), memory function (p &lt; 0.0001), and executive function (p &lt; 0.0001) outcomes after treatment, and significantly improved some dimensional scores on the auditory verbal learning test after treatment (p = 0.04).

Conclusion

Compared with conventional therapy, traditional Chinese mind–body exercises (Tai Chi, Baduanjin, and Qigong) significantly improved global cognitive function, and Baduanjin could improve global cognitive function, memory function, and executive function in older adults with cognitive impairment.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/#searchadvanced, CRD42022327563.

Traditional Chinese Mind-Body Exercise Baduanjin Modulate Gray Matter and Cognitive Function in Older Adults with Mild Cognitive Impairment: A Brain Imaging Study

Background:

Previous studies found traditional Chinese mind-body exercise Baduanjin could modulate cognition of community older adults.

Objective:

This study aims to investigate the effect of 6 months of Baduanjin exercise on brain structure and cognitive function in older adults with mild cognitive impairment (MCI).

Methods:

The MCI older adults were randomly assigned into either Baduanjin training, brisk walking training or usual physical activity control group. Magnetic Resonance Imaging (MRI), Montreal Cognitive Assessment (MoCA) and Wechsler Memory Scale-Chinese Revised (WMS-CR) were applied to measure gray matter volume (GMV), global cognitive ability and memory at baseline and end of intervention.

Results:

Compared to usual physical activity, Baduanjin exercise significantly improved MoCA, WMS-CR scores, WMS-MQ, and mental control and comprehension memory subscores of the WMS-CR; significantly increased the GMV in the temporal gyrus, frontal gyrus, parietal gyrus, medial occipital gyrus, cingulate gyrus and angular gyrus after 6 months of intervention. Compared to brisk walking, Baduanjin significantly improved MoCA scores and picture reproduction subscores of memory, and significantly increased the GMV in the right frontal gyrus, precentral gyrus, occipital gyrus. Furthermore, the increased GMV in the right medial temporal gyrus was significantly associated with improvement in the MoCA scores.

Conclusion:

The present study suggested that regular Baduanjin training could have a positive effect in increasing brain gray matter and improving cognitive function in older adults with MCI.

Diagnosis and Treatment for Mild Cognitive Impairment: A Systematic Review of Clinical Practice Guidelines and Consensus Statements

Background: Mild cognitive impairment (MCI) is an important stage between the normal cognitive decline of aging and dementia. The aim of this study was to compare and harmonize the recommendations for the diagnosis and treatment of MCI based on current clinical practice guidelines. Methods: We searched the PubMed, EMBASE, China National Knowledge Infrastructure, Wanfang Database, Chinese Science and Technology Periodical Database, and Chinese Biological Medicine Database from their inception date to April 24, 2021 to identify all published guidelines on MCI. The qualities of the eligible guidelines were appraised by two reviewers using the Appraisal of Guidelines for Research and Evaluation II instrument. Results: Thirteen guidance documents (four guidelines and nine consensus statements) with specific recommendations were included. Nine guidelines and consensus statements covered the screening and diagnosis of MCI. The evaluation of the documents showed that neuropsychological testing and biomarker assessments were the most common recommendations for the diagnosis of MCI. Nine of the 13 guidance documents covered the treatment and management of MCI. The recommendations for the treatment and management were classified into four categories, namely: intervention for risk reduction, pharmacologic interventions, non-pharmacologic interventions, and counseling. Regarding pharmacological interventions, three guidelines recommend no pharmacologic intervention. The use of cholinesterase inhibitors for MCI is contraindicated in three guidance documents, whereas one proposes that cholinesterase inhibitors and memantine should be deprescribed. EHb761^®, Chinese herbal decoctions, and Chinese traditional patent medicine are recommended in two documents. A total of seven guidance documents recommend non-pharmacological interventions, including physical activity interventions, cognitive interventions, dietary and nutritional interventions, and acupuncture. Conclusion: An updated search for possible evidence on the diagnosis and treatment of MCI is needed. Potentially effective diagnoses and treatments, either conventional or complementary, and alternative therapies should be highly valued and addressed in correlation with the supporting evidence.

Effect of Baduanjin exercise on the cognitive function of middle-aged and older adults: A systematic review and meta-analysis

BACKGROUND

Age-related cognitive decline is a pervasive problem in the ageing population. Baduanjin training is a mind-body exercise with the characteristics of traditional Chinese medicine, and increasing numbers of studies have reported its usefulness in modulating the cognitive performance of various populations. However, no systematic review has evaluated the effect of Baduanjin training on cognition in middle-aged and older adults.

OBJECTIVE

To systematically evaluate the effects of Baduanjin on the global cognitive function and specific cognitive domains of middle-aged and elderly people.

METHODS

Four literature databases (PubMed, Cochrane library, EMBASE, and Web of Science) and four Chinese databases (Wanfang, China National Knowledge Infrastructure, Chinese Science and Technology Periodical and China Biology Medicine) were searched from inception through May 2020. Randomized controlled trials (RCTs) examining the effect of Baduanjin exercise on the cognitive function of middle-aged and elderly people were included. Assessment of the risk of bias for the included studies and data synthesis were conducted using the software Review Manager 5.3 based on the methods given in the Cochrane Handbook.

RESULTS

Baduanjin training showed significant benefit for global cognitive function and parts of specific domains of cognition, including general memory and its sub-domains (i.e., immediate memory and delayed memory), executive function, and processing speed, but no significant difference was found in attention function, visual-spatial ability or long-term memory (a sub-domain of memory). No related adverse events were reported in the included studies.

CONCLUSIONS

The findings of this review suggest that Baduanjin is safe and effective in enhancing global cognitive function and memory in middle-aged and older adults and potentially beneficial to parts of the other specific domains of cognition, including executive function and processing speed. However, additional trials with larger sample sizes and a more rigorous design are needed before more definitive conclusions can be drawn.

Effects of Tai Chi on Patients with Mild Cognitive Impairment: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Design

Randomized controlled trials (RCTs) from multiple databases from inception to December 2020 published in English were searched. Two researchers independently performed eligible study screening and data extraction. The methodological quality was assessed with the Jadad score. Meta-analysis of RCTs on TC in the treatment of MCI was performed with RevMan Version 5.4.1.

Results

Seven RCTs with 1265 participants were included. For most RCTs, the overall reporting of methodological quality was high. Results of the meta-analysis indicate that TC improved MCI patients' cognitive function significantly, including overall cognitive function (MD = −2.24, 95% CI -3.51 to -0.97, P = 0.0005), memory and learning (SMD = 0.83, 95% CI 0.22 to 1.45, P = 0.008), visuospatial ability (MD = 3.15, 95% CI 0.74 to 5.56, P = 0.01), executive functions (MD = 0.32, 95% CI 0.03 to 0.61, P = 0.03), and physical activity (MD = 18.78, 95% CI 10.80 to 26.76, P < 0.00001). However, no significant benefit was found for TC on psychological activity (MD = 0.17, 95% CI -0.62 to 0.96, P = 0.36) and biomarker improvement.

Conclusion

The meta-analysis confirmed the clinical therapeutic effect of TC for MCI. More rigorous and long-term follow-up RCTs should be conducted in the future.

Dose-Response Association of Tai Chi and Cognition among Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis

Previous studies indicated that Tai Chi might be an effective way to improve or prevent cognitive impairments in older populations. However, existing research does not provide clear recommendations about the optimal dose of Tai Chi practice, which is the most effective in improving cognitive function in older adults. The purpose of this systematic review and meta-analysis was to investigate the dose-response relationship between Tai Chi and cognition in community-dwelling older adults. A total of 16 studies with 1121 subjects were included in this study. Meta-regression analyses of Tai Chi duration (Tai Chi session duration, Tai Chi practice duration per week, study duration, and Tai Chi practice duration for the entire study) on the study effect size (ES) were performed to examine the dose-response association of Tai Chi and cognition. The results showed that there was a positive effect of Tai Chi on cognitive function, but there were no statistically significant dose duration effects on cognition. The findings suggest that Tai Chi has beneficial effects on cognitive function, but a longer duration was not associated with larger effects. In order to establish evidence-based clinical interventions using Tai Chi, future research should clearly demonstrate intervention protocol, particularly the style and intensity of Tai Chi.

Effects of Tai Chi Chuan on Cognitive Function in Older Adults with Cognitive Impairment: A Systematic and Meta-Analytic Review

This systematic and meta-analytic review aimed to investigate the effects of Tai Chi Chuan (TCC) on the cognitive function of the elderly with cognitive impairment and to analyze the moderators of these effects. We searched eight electronic databases for randomized controlled trials on the effects of TCC on cognitive function, published up to June 14, 2020. The PEDro scale was used to evaluate the methodological quality of the included literature. Stata14.0 software was used for meta-analysis, subgroup analysis, and publication bias testing. A total of 19 studies and 1,970 samples were included. The methodological quality of the included literature was fair to good, and there was no publication bias. Overall, the research shows that the effect of TCC on the elderly with cognitive impairment is statistically significant (SMD = 0.31, p < 0.0001). Five of the cognitive function subdomains were significant moderators [Q (5) = 15.66, p=0.008], and the effect size (ES) was the largest for global cognitive function (SMD = 0.41), followed by executive function (SMD = 0.33), memory (SMD = 0.31), and verbal fluency (SMD = 0.27). Regarding the exercise prescription variables, results were significantly moderated by the length of exercise training [Q (2) = 6.00, p=0.05], with ESs largest for moderate length (SMD = 0.41), followed by short length (SMD = 0.40) and long length (SMD = 0.29). However, the results were not moderated by session time or frequency. TCC can improve multiple cognitive functions of the elderly with cognitive impairment. The intervention effects are moderated by exercise length, but not by exercise session time and frequency.

Traditional Chinese medicine for mild cognitive impairment: A protocol for systematic review and network meta-analysis

BACKGROUND

Mild cognitive impairment (MCI) is an intermediate stage between normal aging and Alzheimer disease, which is the most common form of dementia in the world. In clinical practice, traditional Chinese medicine (TCM) interventions have been administered for MCI, However, there is still uncertain about what strategy of TCM interventions treatment should be preferred in clinical practice. This study aims to evaluate the efficacy and acceptability of different TCM therapies through systematic review and network meta-analysis.

METHODS

According to the strategy, the authors will retrieve a total of 7 electronic databases by August 2020, including PubMed, the Cochrane Library, EMbase, China National Knowledge Infrastructure, China Biological Medicine, Chongqing VIP, and Wan-fang databases. After a series of screening, 2 researchers will use Aggregate Data Drug Information System and Stata software to analyze the data extracted from the randomized controlled trials of TCM therapies for MCI. The primary outcome of this study is the improvement of cognitive function and the secondary outcome is the activities of daily living, clinical efficacy, and adverse events, and the quality of the evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation instrument.

RESULTS

This study will provide a reliable evidence for the selection of TCM therapies in the treatment of MCI.

CONCLUSION

This study will generate evidence for different TCM therapies for MCI and provide a decision-making reference for clinical research.

ETHICS AND DISSEMINATION

This study does not require ethical approval. The results will be disseminated through a peer-reviewed publication.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/JV9KG.

A pilot feasibility randomized controlled trial on combining mind-body physical exercise, cognitive training, and nurse-led risk factor modification to reduce cognitive decline among older adults with mild cognitive impairment in primary care

Objectives

To examine the feasibility and preliminary effectiveness of (1) combining cognitive training, mind-body physical exercise, and nurse-led risk factor modification (CPR), (2) nurse-led risk factor modification (RFM), and (3) health advice (HA) on reducing cognitive decline among older adults with mild cognitive impairment (MCI).

Methods

It was a 3-arm open-labeled pilot randomized controlled trial in the primary care setting in Hong Kong. Nineteen older adults with MCI were randomized to either CPR (n = 6), RFM (n = 7), or HA (n = 6) for 6 months. The primary outcome was the feasibility of the study. Secondary outcomes included the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), the Montreal Cognitive Assessment Hong Kong version (HK-MoCA), the Clinical Dementia Rating (CDR), the Disability Assessment for Dementia (DAD), quality of life, depression, anxiety, physical activity, health service utilization, and diet.

Results

Nineteen out the 98 potential patients were recruited, with a recruitment rate of 19% (95% CI [12-29]%, P = 0.243). The adherence rate of risk factor modification was 89% (95% CI [65-98]%, P = 0.139) for CPR group and 86% (95% CI [63-96]%, P = 0.182) for RFM group. In the CPR group, 53% (95% CI [36-70]%, P = 0.038) of the Tai Chi exercise sessions and 54% (95% CI [37-71]%, P = 0.051) of cognitive sessions were completed. The overall dropout rate was 11% (95% CI [2-34]%, P = 0.456). Significant within group changes were observed in HK-MoCA in RFM (4.50 ± 2.59, P = 0.008), cost of health service utilization in CPR (-4000, quartiles: -6800 to -200, P = 0.043), fish and seafood in HA (-1.10 ± 1.02, P = 0.047), and sugar in HA (2.69 ± 1.80, P = 0.015). Group × time interactions were noted on HK-MoCA favoring the RFM group (P = 0.000), DAD score favoring CPR group (P = 0.027), GAS-20 favoring CPR group (P = 0.026), number of servings of fish and seafood (P = 0.004), and sugar (P < 0.001) ate per day.

Conclusions

In this pilot study, RFM and the multi-domain approach CPR were feasible and had preliminary beneficial effects in older adults with MCI in primary care setting in Hong Kong.

Trial registration

Chinese Clinical Trial Registry (ChiCTR1800015324).

Tai Chi is Effective in Delaying Cognitive Decline in Older Adults with Mild Cognitive Impairment: Evidence from a Systematic Review and Meta-Analysis

To determine whether Tai Chi (TC) is effective in slowing cognitive decline in older populations with mild cognitive impairment (MCI), we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) on Tai Chi and MCI. We searched eight electronic databases (PubMed, PsycINFO, Wanfang, Web of Science, MEDLINE, CNKI, EBSCO, and the Cochrane Central Register of Controlled Trials) for appropriate RCTs published up to August 2019. For those studies included, the data were extracted, methodological quality was evaluated, and then meta-analysis was performed using Review Manager software (version 5.3). A total of 11 of the studies were available for systematic review, which together included 1061 participants, met the inclusion criteria, and ten of these were included in the meta-analysis. For most RCTs, the methodological quality was moderate. The meta-analysis revealed that Tai Chi could significantly improve global cognitive function; memory and learning; mental speed and attention; ideas, abstraction, figural creations, and mental flexibility; and visuospatial perception. The present review adds to the evidence showing that Tai Chi is potentially beneficial in improving cognitive functions among elderly people with MCI. However, strictly designed and well-reported RCTs are required.

A summary of the evidence and evaluation of the effectiveness of nonpharmacological interventions for mild cognitive impairment

Objective

To summarize and evaluate the evidence of guidelines and systematic reviews (SRs) of nonpharmacological interventions for mild cognitive impairment (MCI) to support the development of future guidelines and clinical decisions for MCI patients.

Methods

Scottish Intercollegiate Guideline Network (SIGN), National Institute for Health and Clinical Excellence (NICE), American Academy of Neurology (AAN), Registered Nurses Association of Ontario (RNAO), Web of Science, PubMed, Cochrane Library, CNAHL, VIP, China National Knowledge Infrastructure (CNKI), and Wanfang Database were searched for relevant publications, including guidelines and SRs, from January 2014 to March 2019. Two authors independently screened articles, extracted data, and assessed the publications for adherence to the inclusion criteria. Appraisal of Guidelines for Research and Evaluation (AGREE II) was used to assess the quality of the guidelines, and Assessment of Multiple Systematic Reviews (AMSTAR 2) was used to assess the quality of SRs. In addition, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to evaluate the quality of outcomes.

Results

Thirty-two articles were retrieved, including 1 guideline and 31 SRs. Fourteen SRs of physical exercise for MCI, six articles describing cognitive interventions, four articles describing acupuncture, and seven articles assessing dietary interventions (including four articles employing a Mediterranean diet, one article using vitamin B supplementation, and two articles assessing the effects of tea, coffee, and caffeine) were included. The quality of the articles was very low for 4 (13%), low for 10 (32%), and moderate for 17 (55%).

Conclusions

Based on the evidence available to date, nonpharmacological interventions may improve the current cognitive function of persons with MCI. In particular, physical exercise, cognitive interventions, and acupuncture exerted promising effects. However, due to the limited number and quality of the included publications, additional high-quality reviews are needed to further confirm.

Physical Activity, Cognition, and Brain Outcomes: A Review of the 2018 Physical Activity Guidelines

PURPOSE

Physical activity (PA) is known to improve cognitive and brain function, but debate continues regarding the consistency and magnitude of its effects, populations and cognitive domains most affected, and parameters necessary to achieve the greatest improvements (e.g., dose).

METHODS

In this umbrella review conducted in part for the 2018 Health and Human Services Physical Activity Guidelines for Americans Advisory Committee, we examined whether PA interventions enhance cognitive and brain outcomes across the life span, as well as in populations experiencing cognitive dysfunction (e.g., schizophrenia). Systematic reviews, meta-analyses, and pooled analyses were used. We further examined whether engaging in greater amounts of PA is associated with a reduced risk of developing cognitive impairment and dementia in late adulthood.

RESULTS

Moderate evidence from randomized controlled trials indicates an association between moderate- to vigorous-intensity PA and improvements in cognition, including performance on academic achievement and neuropsychological tests, such as those measuring processing speed, memory, and executive function. Strong evidence demonstrates that acute bouts of moderate- to vigorous-intensity PA have transient benefits for cognition during the postrecovery period after exercise. Strong evidence demonstrates that greater amounts of PA are associated with a reduced risk of developing cognitive impairment, including Alzheimer's disease. The strength of the findings varies across the life span and in individuals with medical conditions influencing cognition.

CONCLUSIONS

There is moderate-to-strong support that PA benefits cognitive functioning during early and late periods of the life span and in certain populations characterized by cognitive deficits.

Tai Chi for patients with mild cognitive impairment: A protocol for a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Mild cognitive impairment (MCI) is an intermediate stage between the cognitive changes of normal aging and early dementia. Tai Chi (TC) may be particularly beneficial to patients with MCI due to its whole-body coordination characteristics. This systematic review protocol aims to outline the methods that will be used to assess the comparative effectiveness and safety of TC for MCI through a systematic review and meta-analysis.

METHODS

A systematic review will identify and evaluate randomized controlled trials (RCTs) that examined the effects and safety of TC compared to a placebo, conventional treatment, and no treatment on cognitive function in individuals with MCI. Studies from databases of MEDLINE, PubMed, Embase, Global Health, Cochrane Library, and Scopus from January 1990 to March 2019 reported in English will be searched. Two independent reviewers will screen the studies for inclusion with the eligibility criteria and extract data. Risk of bias of individual studies will be assessed in line with Cochrane risk of bias tool. The overall quality of cumulative evidence will be assessed using selected Grading of Recommendations, Assessment, Development, and Evaluations criteria. Statistics will be used for heterogeneity assessment, sensitivity analysis, data synthesis, generating funnel plots, and subgroup analysis. Meta-analysis will be performed, if sufficiently homogeneous studies are found. A narrative synthesis will be conducted, grouping studies by exposure and outcome definitions, and describing any differences by subgroups.

RESULTS

This study will provide practical and targeted evidence in investigating the impact of TC exercise for individuals with MCI.

CONCLUSION

The findings of our study will provide updated evidence to determine whether TC is an effective intervention to patients with MCI.

TRIAL REGISTRATION NUMBER

International Prospective Register for Systematic Reviews (PROSPERO) number CRD42019125104.

Social Networks, Community Engagement, and Cognitive Impairment among Community-Dwelling Chinese Older Adults

Aims

To examine the association of social networks and community engagement with cognitive impairment among community-dwelling Chinese older adults.

Methods

From November 2017 to May 2018, we selected 1,115 elderly individuals from 3 Chinese communities (Beijing, Hefei, and Lanzhou) using a random-cluster sampling method, and recorded data on demographics, social network characteristics, community activities, and cognitive function. The odds ratios (ORs) of these associations were adjusted for potential confounders in logistic regression models.

Results

The prevalence of cognitive impairment was 25.7′ (n = 287). An adequate social network (OR 0.55; 95′ confidence interval [CI] 0.33–0.91) and enough social support from friends (OR 0.43; 95′ CI 0.29–0.62) were negatively associated with cognitive impairment. Family support was not significantly associated with cognitive impairment (OR 0.64; 95′ CI 0.34–1.21). Taking part in elderly group travel, communication with others using WeChat, and community activities such as Tai Chi and walking together were negatively associated with cognitive impairment.

Conclusion

Social network characteristics and community engagement were found to be related to cognitive function among community-dwelling Chinese elderly adults.

The Beneficial Effects of Mind-Body Exercises for People With Mild Cognitive Impairment: a Systematic Review With Meta-analysis

OBJECTIVE

To objectively evaluate the most common forms of mind-body exercise (MBE) (tai chi, yoga, qigong) on cognitive function among people with mild cognitive impairment (MCI).

DATA SOURCES

We searched 6 electronic databases (Scopus, PubMed, PsycINFO, WanFang, Web of Science, CNKI) from inception until September 2018.

STUDY SELECTION

Nine randomized controlled trials and 3 nonrandomized controlled trials were included for meta-analysis.

DATA EXTRACTION

Two researchers independently performed the literature searches, study selection, data extraction, and methodological quality assessment using the revised Physiotherapy Evidence Database (PEDro) scale.

DATA SYNTHESIS

The pooled effect size (standardized mean difference [SMD]) was calculated while random-effect model was selected. Overall results of the meta-analysis (N=1298 people with MCI) indicated that MBE significantly improved attention (SMD=0.39, 95% confidence interval [CI] 0.07-0.71, P=.02, I²=31.6%, n=245), short-term memory (SMD=0.74, 95% CI 0.57-0.90, P<.001, I²=0%, n=861), executive function (SMD=-0.42, 95% CI -0.63 to -0.21, P<.001, I²=38.54%, n=701), visual-spatial/executive function (SMD=0.35, 95% CI 0.07-0.64, P<.05, I²=0%, n=285), and global cognitive function (SMD=0.36, 95% CI 0.2-0.52, P<.001, I²=15.12%, n=902). However, the significant positive effect on cognitive processing speed was not observed following MBE interventions (SMD=0.31, 95% CI -0.01 to 0.63, P=.054, I²=28.66%, n=233).

CONCLUSIONS

Study findings of this meta-analysis suggest that MBE have the potential to improve various cognitive functions in people with MCI.

Reporting of Protocol Rationale and Content Validity in Randomized Clinical Trials of T'ai Chi: A Systematic Evaluation

BACKGROUND

Mind-body exercise interventions are typically multimodal, complex, and pluralistic, and few have been developed with the goal of therapeutically targeting a specific medical population. It is thus important that clinical trials evaluating mind-body interventions provide some justification for the use of the specific protocol being evaluated.

OBJECTIVES

This article reports the results of a systematic review of the quality of reporting of protocol rationale and content validity for using a specific t'ai chi protocol in a randomized controlled trial (RCT).

METHODS

Electronic literature searches were conducted using PubMed/MEDLINE, EBSCOhost, and the Cochrane Library from inception through June 2015. Search terms were Tai Chi, Taiji, Tai Chi Chuan; searches were limited to English-language RCTs. Inclusion and exclusion of trials were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The authors assessed the level of reporting with respect to t'ai chi protocol validation using a 5-point grading system based on whether (1) a specific protocol was mentioned, (2) rationale for the specific protocol was stated and supported, and (3) formal evaluation for content validity was conducted.

RESULTS

There was significant heterogeneity in the quality of reporting related to protocol rationale and content validity. A total of 171 publications were identified. Studies met between 0 and 4 validity criteria (of possible 5, more indicating better quality), with a mean of 2.52 (±SD 1.2) and median of 3. Twenty (12%) trials did not mention a specific t'ai chi protocol, 10 (6%) trials met 0 of 5 criteria, and 47 (31%) studies met 4 of 5 criteria. Formal validity assessments were employed in only one trial.

CONCLUSIONS

The poor quality of protocol rationale and content validity reporting limits our ability to accurately evaluate the evidence of t'ai chi as a therapeutic intervention. The development of formal guidelines for developing and reporting intervention validity for multimodal mind-body exercises like t'ai chi may improve the quality and interpretability of research.

Effects of Mind-Body Exercise on Cognitive Function in Older Adults With Cognitive Impairment: A Systematic Review and Meta-analysis

To quantify the effects of mind-body exercise on cognitive function in older adults with cognitive impairment, we systematically searched five databases. Findings were analyzed according to the mean change of global cognition, memory, and executive function. Subgroup analyses were conducted based on the level of cognitive impairment and types of exercise. Thirteen studies were included. Analyses revealed that mind-body exercise was effective in promoting global cognition in individuals with cognitive impairment (standardized mean difference [SMD] = 0.61; 95% confidence interval, 0.21-1.00; p = 0.003), as well as in individuals with mild cognitive impairment (SMD = 0.46; 95% confidence interval, 0.06-0.85; p = 0.02) or dementia; dance was effective in promoting global cognition (SMD = 0.84; 95% confidence interval, 0.23-1.46; p = 0.007) and memory (SMD = 0.27; 95% confidence interval, 0.02-0.52; p = 0.04) in individuals with cognitive impairment, but tai chi was not. Nevertheless, additional well-designed randomized clinical trials are further needed.