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

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 mind-body exercise on cognitive performance in middle-aged and older adults with mild cognitive impairment: A meta-analysis study

BACKGROUND

To systematically evaluate the clinical efficacy of physical and mental exercise on cognitive performance in middle-aged people with mild cognitive impairment (MCI).

METHODS

Computer searches of PubMed, Web of science, Embase, Cochrane Library, China Biomedical Literature Service, Wanfang database, China Knowledge Network, and VIP full-text database of Veep journals were conducted to obtain clinical randomized controlled trials on physical and mental exercise interventions in middle-aged and elderly people with MCI. The literature was screened according to inclusion and exclusion criteria, and the final included literature was subjected to data extraction and risk of bias assessment. Meta-analysis was performed using Review Manager 5.4.1 software, and publication bias test was performed using stata17.0 software.

RESULTS

A total of 27 publications with a total of 2565 cases of elderly people with MCI were included. The control group was conventional care, health education, or blank control, and the physical and mental exercise group was exercises including Tai Chi, dance, orthopraxia, and qigong for 30 to 90 minutes each time, 3 to 6 times per week, for a total duration of 8 to 36 weeks. Meta-analysis results showed that Montreal cognitive assessment scores (mean difference [MD] = 2.33, 95% CI [1.55, 3.10], P < .00001), the mini-mental state examination score (MD = 1.73, 95% CI [0.60, 2.86], P = .003), trail making test-A score (MD = -4.00, 95% CI [-6.75, -1.25], P = .004), trail making test-B score (MD = -18.46, 95% CI [-23.87, -13.06], P < .00001), global deterioration scale score (MD = -0.72, 95% CI [-1.09, -0.34], P = .0002), Wechsler Logical Memory Scale score (MD = 2.07, 95% CI [0.03, 4.10], P = .05), berg score (MD = -0.70, 95% CI [0.32, 1.07], P < .0003), cerebrospinal fluid Tau protein level (MD = -166.69, 95% CI [-196.93, -136.45], P < .00001), and cerebrospinal fluid levels of αβ1-42 protein (MD = 180.39, 95% CI [134.24, 226.55], P < .00001).

CONCLUSION

Mind-body exercise can improve cognitive performance, depressive status, and balance as well as increase αβ1-42 protein levels and decrease Tau protein levels in middle-aged and older adults with mild cognitive impairment.

Investigating Inter- and Intra-individual Differences in Tai Chi Practice Time, Pain, and Mood Among Participants with Chronic Nonspecific Neck Pain: Secondary Analysis of a Randomized Controlled Trial

Background: Tai Chi is emerging as a promising treatment for a variety of pain conditions, including chronic nonspecific neck pain. Given this trend, it is important to better understand the dose-response relationship and how pain, anxiety, and depression impact this relationship. Method: This secondary analysis used data from the Tai Chi arm (age = 52.03 ± 10.92 years; 73.68% female; n = 38) of a randomized controlled trial for chronic nonspecific neck pain. The authors tested whether (1) greater home practice time or cumulative practice time during the intervention predicted greater post-treatment reductions in neck pain intensity and (2) reporting greater neck pain intensity during the current week relative to other weeks was associated with lower home practice time during the current week. Post hoc analyses were conducted to evaluate whether baseline anxiety and depression levels moderated the association between weekly pain intensity and weekly home practice time. Results: While cumulative Tai Chi practice time (i.e., home practice + class time) was associated with post-treatment reductions in neck pain intensity, home practice time alone was not associated with post-treatment reductions in neck pain. Participants with low and moderate baseline anxiety were found to practice less than usual on weeks when pain intensity was worse, while participants with high baseline anxiety were found to practice more than usual on weeks when pain intensity was worse. Baseline depression levels did not moderate the effect of weekly pain intensity on weekly home practice time. Conclusions: Combined class and at-home exposure to Tai Chi appears to be critical to reductions in chronic nonspecific neck pain. In addition, anxiety may be an important characteristic that partially governs the dose-response relationship in participants with chronic nonspecific neck pain. Clinical Trial Registration: NCT02222051.

The effect of Tai Chi in elderly individuals with sarcopenia and frailty: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The potential role of Tai Chi in improving sarcopenia and frailty has been shown in randomized controlled trials (RCTs). This systematic review and meta-analysis aimed to examine the effect of Tai Chi on muscle mass, muscle strength, physical function, and other geriatric syndromes in elderly individuals with sarcopenia and frailty.

METHODS

Systematic searches of the PubMed, Cochrane Library, PEDro, EMBASE, Web of Science, CINAHL, and Medline databases for RCTs published between 1989 and 2022 were conducted; the database searchers were supplemented with manual reference searches. The inclusion criteria were as follows: (1) the study was designed as a RCT; (2) Tai Chi was one of the intervention arms; (3) the participants had a minimum age of ≥ 60 years and were diagnosed with frailty or sarcopenia, and the diagnostic guidelines or criteria were mentioned; (4) the number of participants in each arm was ≥ 10; and (5) the outcome reports included ≥ 1 item from the following primary or secondary outcomes. The exclusion criteria were as follows: (1) non-RCT studies; (2) nonhuman subjects; (3) participants aged < 60 years; (4) no description of the diagnostic guidelines or criteria for frailty or sarcopenia in the text; and (5) reported outcomes not among the following primary or secondary outcomes. The primary outcomes were muscle mass, grip strength and muscle performance (gait speed, 30-second chair stand test (30CST), sit-to-stand test (SST), Timed up and go test (TUGT), balance, and the Short Physical Performance Battery (SPPB)). The secondary outcomes included the number of falls and fear of falling (FOF), diastolic blood pressure (DBP), Mini-Mental State Examination (MMSE) score, and depression and quality of life (QOL) assessments.

RESULTS

Eleven RCTs were conducted from 1996 to 2022 in 5 countries that investigated 1676 sarcopenic or frail elderly individuals were included in the review. There were 804 participants in the Tai Chi exercise cohort and 872 participants in the control cohort (nonexercised (n = 5)/ exercise (n = 8)). The mean age of participants was 70-89.5 years and the numbers of participants from each arm in each study were 10-158. The majority of the participants practiced Yang-style Tai Chi (n = 9), and the numbers of movement ranged from 6 to 24. The prescriptions of training were 8-48 weeks, 2-7 sessions per weeks, and 30-90 min per session. Most studies used Tai Chi expert as instructor (n = 8). The lengths of follow-up period were 8-48 weeks. The results from our meta-analysis revealed significant improvements for Tai Chi compared to control group (nonexercise/ exercise) on measures of the 30CST (weighted mean difference (WMD): 2.36, 95% confidence interval (CI) 1.50-3.21, p < 0.00001, I² = 87%), the TUGT (WMD: -0.72, 95% CI -1.10 to -0.34, p = 0.0002, I² =0%), numbers of fall (WMD: -0.41, 95% CI -0.64 to -0.17, p = 0.0006, I² =0%) and FOF (standardized MD (SMD): -0.50, 95% CI -0.79 to -0.22, p = 0.0006, I² = 57%); and for Tai Chi compared to 'nonexercise' controls on measures of SST (WMD: -2.20, 95% CI -2.22 to -2.18, p < 0.00001), balance (SMD: 9.85, 95% CI 8.88-10.82, p < 0.00001), DBP (WMD: -7.00, 95% CI -7.35 to -6.65, p < 0.00001), MMSE (WMD: 1.91, 95% CI 1.73-2.09, p < 0.00001, I² =0%), depression (SMD: -1.37, 95% CI -1.91 to -0.83, p < 0.00001) and QOL (SMD: 10.72, 95% CI 9.38-12.07, p < 0.00001). There were no significant differences between Tai Chi and control groups on any of the remaining 4 comparisons: body muscle mass (WMD: 0.53, 95% CI -0.18 to 1.24; P = 0.14; I² =0%), grip strength (WMD: -0.06, 95% CI -1.98 to 1.86; P = 0.95; I² =0%), gait speed (WMD: 0.05, 95% CI -0.11 to 0.20; P = 0.55; I² =99%), and SPPB (WMD: 0.55, 95% CI -0.04 to 1.14; P = 0.07). The variables of bias summary, Tai Chi instructor, Tai Chi movements, and Tai Chi training duration without significant association with the 30CST or the TUGT through meta-regression analyses.

CONCLUSIONS

Our results demonstrated that patients with frailty or sarcopenia who practiced Tai Chi exhibited improved physical performance in the 30-second chair stand test, the Timed up and go test, number of falls and fear of falling. However, there was no difference in muscle mass, grip strength, gait speed, or Short Physical Performance Battery score between the Tai Chi and control groups. Improvements in the sit-to-stand test, balance, diastolic blood pressure, Mini-Mental State Examination score, and depression and quality of life assessments were found when comparing the Tai Chi cohort to the nonexercise control cohort rather than the exercise control cohort. To explore the effectiveness of Tai Chi in sarcopenic and frail elderly individuals more comprehensively, a standardized Tai Chi training prescription and a detailed description of the study design are suggested for future studies.

The Effects of Tai Chi on the Executive Functions and Physical Fitness in Middle-Aged Adults with Depression: A Randomized Controlled Trial

Objective

The present study examined the effects of Tai Chi exercise on the executive functions (EFs) and physical fitness of middle-aged adults with depression.

Methods

A total of 39 middle-aged adults with depression (M_age = 50.59, SD = 7.38) were randomly assigned to the Tai Chi group (n = 20) or the waiting-list control group (n = 19). The Tai Chi group engaged in two 90 min sessions of Tai Chi exercise per week for 12 weeks; the waiting-list control group was asked to maintain their usual daily routines for 12 weeks. Depression symptoms, EFs (i.e., inhibitory control, planning, working memory, and cognitive flexibility), and physical fitness (i.e., cardiovascular fitness, muscular strength, muscular endurance, power, and flexibility) were evaluated at the baseline (pretest), 6-week (mid-test), and 12-week (post-test) marks.

Results

Both groups showed decreased depression symptoms over time. Compared with the control group, the Tai Chi group showed decreased reaction times for incongruent conditions in the Stroop test from pretest to mid- and post-test, and shorter reaction time for incongruent conditions in the Stroop test than the control group at post-test; the Tai Chi group performed significantly better than the control group in overall total move score of Tower of London (TOL). The Tai Chi group also showed increased total correct scores of TOL from pretest to mid- and post-test, and greater total correct scores of TOL than the control group at post-test. Additionally, results indicated that Tai Chi exercise comprehensively improved physical fitness from pretest to mid- and post-test. Greater performance in terms of cardiovascular fitness, muscular strength, and power was also found in the Tai Chi group at post-test than in the control group.

Conclusions

These findings suggest that the 12-week Tai Chi exercise improved inhibitory control, planning and working memory aspects of executive functions, and physical fitness in middle-aged adults with depression.

Combined Tai Chi and cognitive interventions for older adults with or without cognitive impairment: A meta-analysis and systematic review

BACKGROUND AND PURPOSE

Evidence from the field of cognitive interventions indicates that nonpharmaceutical interventions seem more promising in enhancing cognition. The number of clinical trials that examine the cognitive benefits of combined physical exercise with cognitive intervention on older adults has recently increased. Tai Chi (TC) has been recommended as an effective and safe exercise for older adults aged 60 and over. However, there is a lack of conclusion about whether combined TC with cognitive interventions can show more benefits than a single intervention for older adults. Thus, this review aimed to evaluate the effects of combined TC and cognitive interventions on older adults.

METHODS

PubMed, Embase, PsycINFO, and Web of Science were searched for English peer-reviewed papers from inception until November 12, 2021. Data were extracted by two independent reviewers.

RESULTS

A total of 1524 records were generated and nine studies were included. The pooled results showed that combined TC and cognitive interventions showed significantly large gains on memory [standardised mean difference (SMD) = 0.87, 95% confidence interval (CI): (0.01, 1.74), P 0.05], moderate gains on cognition [SMD = 0.74, 95% CI:(0.19, 1.29), P 0.05], and small size effects on balance. No statistically significant difference was found in executive function, depression, risk of falls, or well-being.

CONCLUSION

Combined TC and cognitive interventions have positive effects on improving cognition and balance in older adults, but their superiority over the single intervention, as well as their additional effects on the physical and psychological function, are required further investigation.

Exercise Training for Mild Cognitive Impairment Adults Older Than 60: A Systematic Review and Meta-Analysis

Background:

The prevalence of mild cognitive impairment (MCI) continues to increase due to population aging. Exercise has been a supporting health strategy that may elicit beneficial effects on cognitive function and prevent dementia.

Objective:

This study aimed to examine the effects of aerobic, resistance, and multimodal exercise training on cognition in adults aged > 60 years with MCI.

Methods:

We searched the Cochrane Library, PubMed, and Embase databases and ClinicalTrials.gov (https://clinicaltrials.gov) up to November 2021, with no language restrictions. We included all published randomized controlled trials (RCTs) comparing the effect of exercise programs on cognitive function with any other active intervention or no intervention in participants with MCI aged > 60 years.

Results:

Twelve RCTs were included in this review. Meta-analysis results revealed significant improvements in resistance training on measures of executive function (p < 0.05) and attention (p < 0.05); no significant differences were observed between aerobic exercise and controls on any of the cognitive comparisons.

Conclusion:

Exercise training had a small beneficial effect on executive function and attention in older adults with MCI. Larger studies are required to examine the effects of exercise and the possible moderators.

Determining Whether Tai Chi Chuan Is Related to the Updating Function in Older Adults: Differences Between Practitioners and Controls

Background

Tai Chi Chuan (TCC) is an effective method for delaying cognitive decline in older adults. However, in older adults, the association between long-term TCC practice and working memory updating has not been extensively studied.

Objective

This cross-sectional study investigated how updating function operationalized via Reaction Times (RTs) and Accuracy Rates (ARs) of N-Back tasks being measured in a laboratory setting is related to long term practice of TCC.

Methods

Twenty-six healthy elderly people participated in this experiment. According to the duration of time TCC was practiced, 13 subjects in the TCC group had more than 5 years of experience with TCC exercise, and 13 elderly subjects who had not been systematically exposed to mind-body exercise were assigned to the control group. The N-back task was administered to every participant to evaluate the updating function.

Results

The TCC group had faster RTs than the control group (p < 0.05). For the 1-back task, the TCC group showed faster RTs than the control group; for the 2-back task, the TCC group exhibited faster RTs than the control group. The TCC group had higher ARs than the control group (p < 0.05). For the 1-back task, the TCC group showed higher ARs than the control group; for the 2-back task, the TCC group exhibited higher ARs than the control group.

Conclusions

Long-term TCC practitioners exhibit a better updating function as compared to controls who did not practice TCC. Thus, our findings suggest that long-term TCC positively influences the updating function of older adults, making it, in turn, an effective mind-body exercise to maintain specific aspects of cognitive functioning.

Effect of Tai Chi on Cognitive Function among Older Adults with Cognitive Impairment: A Systematic Review and Meta-Analysis

Background

Cognitive decline occurs in all persons during the aging process and drugs can only alleviate symptoms and are expensive. Some researches demonstrated that Tai Chi had potential in preventing cognitive decline while others' results showed Tai Chi had no influence on cognitive impairment. Therefore, we conduct a systematic review and meta-analysis to assess the efficacy and safety of cognitive impairment patients practicing Tai Chi.

Methods

A comprehensive literature search was carried out in multiple databases, including PubMed, Cochrane, MEDLINE (Ovid), Web of Science, Embase, Scopus, PsycInfo (Ovid), CKNI, Wan Fang, VIP, SinoMed, and ClinicalTrails, from their inception to 1 July 2020 to collect randomized controlled trials about practicing Tai Chi for patients with cognitive impairment. Primary outcomes included changes of cognitive function and secondary outcomes included changes of memory functions. Data were extracted by two independent individuals and Cochrane Risk of Bias tool version 2.0 was applied for the included studies. Systematic review and meta-analysis were performed by RevMan 5.3 software.

Results

The results included 827 cases in 9 studies, of which 375 were in the experimental group and 452 were in the control group. Meta-analysis showed that Mini-Mental State Examination WMD = 1.52, 95% CI [0.90, 2.14]; Montreal Cognitive Assessment WMD = 3.5, 95% CI [0.76, 6.24]; Clinical Dementia Rating WMD = −0.55, 95% CI [−0.80, −0.29]; logical memory delayed recall WMD = 1.1, 95% CI [0.04, 2.16]; digit span forward WMD = 0.53, 95% CI [−0.65, 1.71]; and digit span backward WMD = −0.1, 95% CI [−0.38, 0.19]. No adverse events were reported in the included articles.

Conclusion

There is limited evidence to support that practicing Tai Chi is effective for older adults with cognitive impairment. Tai Chi seems to be a safe exercise, which can bring better changes in cognitive function score.