Exercise programs have been introduced to improve cognitive function, whereas studies showed inconsistent results regarding the effectiveness of exercise programs on patients with dementia. This study aimed to summarize randomized controlled trials (RCTs) to assess the effect of exercise programs on cognition, activities of daily living (ADL), and depression in elderly with dementia. We systematically screened PubMed, Embase, and the Cochrane library for relevant studies throughout November 21, 2018. The pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were employed to calculate cognition, ADL, and depression by using random-effects model. A total of 20 RCTs with 2,051 dementia patients were included in final quantitative meta-analysis. There were no significant differences between exercise programs and control regarding cognition (SMD: 0.44; 95% CI: −0.21–1.09;
Dementia is a major neurological disorder that causes disability and dependency among individuals, and so it has become a significant global problem. The prevalence of dementia among the elderly (≥60 years) people is 4.86% worldwide [
According to a previous study, exercise assists in gradually slowing down the progression of dementia. The potential reasons for this could be the fact that regular exercise has direct effects on the brain cortex, neuromuscular and cardiovascular functioning, immune system, arteriosclerosis in the brain, mood, and depression states [
This study was conducted and reported according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis Statement (PRISMA) [
Two authors independently conducted literature search and study selection, and any inconsistencies between them were resolved by discussion with each other. The inclusion criteria of this study are as follows: (1) patients: patients without any restriction to age were diagnosed with dementia according to the diagnosis criteria in individual trial; (2) intervention: patients received regular exercise programs, and the details of exercise programs have been listed in Table
Baseline characteristic of studies included in the systematic review and meta-analysis.
Study | Publication year | Country | Sample size | Mean age (years) | Percentage male | Setting | Intervention | Control | Treatment duration | Diagnosis criteria | Reported outcomes | Jadad scale |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Francese et al. [ |
1997 | USA | 6/5 | NA | NA | Nursing home | Exercises targeting strength and function that included the use of music, various types of exercise balls, and parachute leg weights | Social contact plus sing-along group that watched music videos | 7 weeks | Clinical | ADL (CADS) | 3 |
|
||||||||||||
de Winckel et al. [ |
2004 | Belgium | 15/10 | 81.6 | 0.0 | Public psychiatric hospital | Intervention focused on strength training, balance, trunk movements, and flexibility | Social contact 1-on-1 conversation with therapist | 3 months | NIN CDS-ARDRA | Cognition (MMSE, ADS 6) | 4 |
|
||||||||||||
Rolland et al. [ |
2007 | France | 67/67 | 83.0 | 24.6 | Nursing home | Aerobic (walking), strength (lower extremity), flexibility, and balance training, gradually increased in intensity | Usual care | 12 months | NIN CDS-ARDRA | ADL (Katz index of ADLs), depression (MADRS) | 6 |
|
||||||||||||
Christofoletti et al. [ |
2008 | Brazil | 17/20 | 74.3 | 32.4 | NA | Physiotherapy kinesiotherapy exercises (strength, balance, memory, and recognition exercise using balls, elastic ribbons, and proprioceptive plates) | Usual care | 6 months | ICD-10, CMBD, and confirmed by the patient’s performance on the MMSE and on KADL scale | Cognition (MMSE) | 4 |
|
||||||||||||
Williams and Tappen [ |
2008 | USA | 33/12 | 87.9 | 11.0 | Nursing home | Exercise focusing on strength, flexibility, and balance; supervised walking | Social contact-conversation | 16 weeks | NINCDS-ADRDA | Depression (CSDD) | 4 |
|
||||||||||||
Eggermont et al. [ |
2009 | The Netherlands | 51/46 | 85.4 | 18.6 | Nursing home | Walking group, walks occurred on unit wards and in public places | Social contact | 6 weeks | Clinical | Cognition (MMSE) | 5 |
|
||||||||||||
Eggermont et al. [ |
2009 | The Netherlands | 30/31 | 84.6 | NA | Nursing home | Hand movement activity group performing activities such as “finger movement, pinching a soft ball, or handling a rubber ring” | Social contact plus read out loud program | 6 weeks | DSM-IV | Cognition (RBMT), depression (GDS) | 5 |
|
||||||||||||
Conradsson et al. [ |
2010 | Sweden | 191 | 84.7 | 27.0 | Nursing home | The high-intensity group exercise (3–9 participants per exercise group) focused on weight bearing and progressively increased in difficulty. Activity consisted of strength and balance exercises including walking, squats, and trunk exercises | Social contact plus seated activities provided by occupational therapists | 13 weeks | KADL scale | ADL (Katz index of ADLs) | 5 |
|
||||||||||||
Kemoun et al. [ |
2010 | France | 20/18 | 81.9 | 21.1 | Nursing home | The exercise program included three different sessions each week, i.e., (1) walking, (2) stamina exercise, and (3) a combination of walking, stamina, and balance exercises. For the first 2 weeks of the program, participants prepared for the routine program with specific muscles and joint exercises | Usual care | 15 weeks | DSM-IV | Cognition (ERFC French version) | 3 |
|
||||||||||||
Hwang and Choi [ |
2010 | Korea | 10/8 | 81.5 | NA | NA | A dance program consisting mainly of upper body exercises, with a 10-minute warm-up and warm-down | Usual care | 8 weeks | Clinical | Cognition (MMSE) | 2 |
|
||||||||||||
Venturelli et al. [ |
2011 | Italy | 12/12 | 84.0 | 37.5 | Nursing home | A minimum of 30 minutes of moderate walking 4 times a week for 6 months | Usual care at the home, which consisted of bingo, sewing, and music therapy | 6 months | Clinical | Cognition (MMSE), ADL (Barthel index of ADL) | 5 |
|
||||||||||||
Vreugdenhil et al. [ |
2012 | Australia | 20/20 | 74.1 | 40.0 | Outpatient memory disorders clinic | Exercises progressively became more challenging, and targeted strength and balance | Usual care | 4 months | DSM-IV | Cognition (ADAS-cog), ADL (The instrumental ADL), depression (GDS) | 6 |
|
||||||||||||
Volkers [ |
2012 | The Netherlands | 50/38 | 82.1 | NA | NA | Supervised walks | Usual care | 18 months | Clinical | Cognition (MMSE) | 3 |
|
||||||||||||
Yang et al. [ |
2015 | China | 25/25 | 72.0 | 34.0 | Neurology clinic | 5 min warm-up, 30 min target intensity exercise, 5 min reorganization movement | Health education | 3 months | NINDS-AIREN and MMSE | Cognition (MMSE, adas-cog), ADL (Qol-AD) | 3 |
|
||||||||||||
Ohman et al. [ |
2016 | Finland | 70/70 | 78.1 | 63.6 | Community | Dual-task exercises, and strength, balance, endurance, and aerobic training; aerobic, endurance, balance, and strength training, and dual tasking | Usual care | 12 months | NINCDS-ADRDA | Cognition (CDT, VF, CDR, MMASE) | 5 |
|
||||||||||||
Toots et al. [ |
2016 | Sweden | 93/93 | 85.1 | 24.2 | Residential care facilities | High-intensity functional exercise program, which aims to improve lower limb strength, balance, and mobility | Seated control activity | 7 months | DSM-IV-TR | Cognition (BBS), ADL (FIM and Barthel index of ADLs), depression (GDS) | 6 |
|
||||||||||||
Hoffmann et al. [ |
2016 | Denmark | 107/93 | 70.5 | 56.5 | NA | The first four weeks of exercise (adaption) emphasized getting used to exercising and building up strength, primarily of the lower extremities (twice weekly). Participants were also introduced to aerobic exercise (once weekly). For the remaining 12 weeks, patients performed aerobic exercise of moderate-to-high intensity (in total 3 × 10 min on an ergometer bicycle, cross trainer, and treadmill with 2–5 min rest between) | Usual care | 16 weeks | NINCDS-ADRDA | Cognition (SDMT), ADL (ADCS-ADL), depression (HAMD-17) | 5 |
|
||||||||||||
Barreto et al. [ |
2017 | France | 44/47 | 87.6 | 15.4 | Nursing home | 10 minutes of warm-up, 10 minutes of coordination and balance exercises, 10–15 minutes of muscle strengthening, 20 minutes of aerobic exercise, and 5–10 minutes of cool down | Music mediation or arts and crafts | 24 weeks | DSM-IV and MMSE | Cognition (MMSE), ADL (ADCS-ADL-sev) | 6 |
|
||||||||||||
Bürge et al. [ |
2017 | Switzerland | 78/82 | 81.4 | 48.8 | Psychiatric hospital | Squatting at different levels (or repeated stand-ups from a chair), lateral elevation of the legs in a standing position, and rising on the toes | Watching videos about different topics or playing together | 6 weeks | CIM-10, and CDR | ADL (Barthel index of ADLs) | 6 |
|
||||||||||||
Lamb et al. [ |
2018 | UK | 278/137 | 77.3 | 60.7 | National health service primary care, community and memory services | Arm exercises using hand held dumb bells, including at least a biceps curl and, for more able individuals, shoulder forward raise, lateral raise, or press exercises, and leg strength training exercises using a sit-to-stand weighted vest (all proexercise products, FL) or a waist belt (Rehabus, Lerum, Sweden), or both | Usual care | 12 months | DSM-IV and MMSE | Cognition (ADAS-cog), ADL (Bristol ADL) | 5 |
Data collection and quality assessment were carried out by 2 authors, and disagreement was adjudicated by an additional author by reading the full text of the article. The collected items included study, publication year, country, sample size, mean age, intervention, control, treatment duration, diagnostic criteria, and reported outcomes. The quality of included studies was evaluated by using the revised Jadad scale that is based on random sequence generation, allocation concealment, blinding, blinding of outcome assessment, incomplete outcome data, selective reporting, and other biases [
The treatment effects of exercise programs versus control on cognition, ADL, and depression based on mean, standard deviation, and sample size in each group in individual trial were calculated. The pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated for cognition, ADL, and depression using random-effects model [
The electronic searches produced 2,146 records, and manual search of the reference lists of retrieved studies identified 59 studies. One hundred and twenty records were removed due to duplicate topics, and 2,042 studies were excluded due to irrelevant topics after studying the title and abstract. The remaining 43 studies were retrieved for full-text evaluations, and 23 studies of these were excluded due to the following reasons: no sufficient data (
Flow diagram of literature search and trials selection process.
A total of 20 RCTs involving a total of 2,051 patients with dementia were included in the final analysis. The studies published between 1997 and 2018 and sample sizes ranged from 11 to 415 were included. The mean age of patients ranged from 70.5 to 87.9 years, and the treatment duration ranged from 6 weeks to 18 months. Fourteen studies were conducted in Europe, and the remaining 6 studies were conducted in USA, Brazil, Australia, Korea, and China. Eleven studies compared the exercise program with other strategies, while the remaining 9 studies compared the exercise program with usual care. The revised Jadad scale was used for quality evaluation, where 5 studies scored 6, 7 studies scored 5, 3 studies scored 4, 4 studies scored 3, and the remaining 1 study scored 2.
Data regarding the effect of exercise program on cognition was available in 15 studies, and the pooled SMD indicated no significant differences between exercise program and control for cognition level (SMD: 0.44; 95% CI: −0.21 to 1.09;
Effect of exercise programs on cognition.
Subgroup analyses for cognition, ADL, and depression.
Outcomes | Factors | Groups | SMD and 95% CI |
|
Heterogeneity (%) |
|
|
---|---|---|---|---|---|---|---|
Cognition | Publication year | Before 2010 | −0.03 (−0.37 to 0.30) | 0.845 | 31.4 | 0.224 | 0.366 |
2010 or after | 0.61 (−0.24 to 1.47) | 0.160 | 97.6 | <0.001 | |||
Country | Europe | 0.31 (−0.47 to 1.08) | 0.435 | 97.4 | <0.001 | 0.001 | |
Others | 0.83 (−0.28 to 1.93) | 0.145 | 89.1 | <0.001 | |||
Sample size | ≥100 | 0.15 (−1.18 to 1.48) | 0.825 | 98.8 | <0.001 | 0.286 | |
<100 | 0.57 (−0.06 to 1.21) | 0.076 | 90.2 | <0.001 | |||
Mean age (years) | ≥80.0 | 0.09 (−0.84 to 1.01) | 0.854 | 96.1 | <0.001 | <0.001 | |
<80.0 | 0.97 (0.07 to 1.87) | 0.035 | 96.6 | <0.001 | |||
Control | Usual | 1.06 (0.35 to 1.76) | 0.003 | 95.1 | <0.001 | <0.001 | |
Others | −0.47 (−1.56 to 0.61) | 0.395 | 96.6 | <0.001 | |||
Treatment duration (months) | ≥6 | 0.45 (−1.01 to 1.90) | 0.548 | 98.6 | <0.001 | 0.563 | |
<6 | 0.42 (−0.11 to 0.95) | 0.123 | 88.9 | <0.001 | |||
Study quality | High | 0.43 (−0.51 to 1.38) | 0.371 | 98.0 | <0.001 | 0.006 | |
Low | 0.44 (0.06 to 0.83) | 0.024 | 51.2 | 0.069 | |||
|
|||||||
ADL | Publication year | Before 2010 | 0.18 (−0.18 to 0.54) | 0.328 | 0.0 | 0.549 | 0.706 |
2010 or after | 0.59 (−0.02 to 1.21) | 0.060 | 95.9 | <0.001 | |||
Country | Europe | 0.29 (−0.28 to 0.87) | 0.317 | 95.6 | <0.001 | 0.001 | |
Others | 1.13 (−0.68 to 2.94) | 0.223 | 92.3 | <0.001 | |||
Sample size | ≥100 | 0.37 (−0.13 to 0.88) | 0.145 | 94.1 | <0.001 | 0.068 | |
<100 | 0.75 (−0.98 to 2.48) | 0.395 | 96.3 | <0.001 | |||
Mean age (years) | ≥80.0 | 0.43 (−0.44 to 1.31) | 0.334 | 96.6 | <0.001 | 0.023 | |
<80.0 | 0.57 (−0.08 to 1.23) | 0.088 | 90.7 | <0.001 | |||
Control | Usual | 0.87 (0.19 to 1.54) | 0.012 | 92.9 | <0.001 | 0.080 | |
Others | 0.14 (−0.76 to 1.04) | 0.757 | 96.3 | <0.001 | |||
Treatment duration (months) | ≥6 | 0.97 (−0.01 to 1.95) | 0.053 | 96.5 | <0.001 | <0.001 | |
<6 | 0.22 (−0.43 to 0.88) | 0.504 | 93.6 | <0.001 | |||
Study quality | High | 0.56 (−0.04 to 1.15) | 0.066 | 95.9 | <0.001 | 0.681 | |
Low | 0.35 (−0.16 to 0.86) | 0.180 | 0.0 | 0.347 | |||
|
|||||||
Depression | Publication year | Before 2010 | −0.13 (−0.41 to 0.14) | 0.337 | 0.0 | 0.805 | 0.555 |
2010 or after | −0.85 (−1.83 to 0.12) | 0.085 | 94.2 | <0.001 | |||
Country | Europe | −0.12 (−0.29 to 0.06) | 0.191 | 0.0 | 0.778 | 0.003 | |
Others | −1.33 (−4.07 to 1.41) | 0.341 | 96.0 | <0.001 | |||
Sample size | ≥100 | −0.10 (−0.29 to 0.08) | 0.285 | 0.0 | 0.640 | 0.022 | |
<100 | −0.94 (−2.40 to 0.52) | 0.209 | 93.1 | <0.001 | |||
Mean age (years) | ≥80.0 | −0.16 (−0.37 to 0.05) | 0.129 | 0.0 | 0.913 | 0.558 | |
<80.0 | −1.34 (−4.03 to 1.35) | 0.329 | 97.1 | <0.001 | |||
Control | Usual | −0.85 (−1.90 to 0.19) | 0.110 | 94.2 | <0.001 | 0.757 | |
Others | −0.17 (−0.42 to 0.08) | 0.186 | 0.0 | 0.773 | |||
Treatment duration (months) | ≥6 | −0.18 (−0.42 to 0.07) | 0.159 | 0.0 | 0.823 | 0.797 | |
<6 | −0.66 (−1.56 to 0.24) | 0.153 | 91.4 | <0.001 | |||
Study quality | High | −0.52 (−1.06 to 0.02) | 0.058 | 88.4 | <0.001 | 0.440 | |
Low | 0.05 (−0.61 to 0.71) | 0.876 | — | — |
Data regarding the effect of exercise program on ADL was available in 11 studies. We noted that exercise program has no significant effect on the levels of ADL when compared with control (SMD: 0.50; 95% CI: −0.03 to 1.02;
Effect of exercise programs on ADL.
Data regarding the effect of exercise program on depression was available in 6 studies. The pooled SMD suggested that exercise programs did not yield any beneficial effects on depression level (SMD: −0.43; 95% CI: −0.90 to 0.05;
Effect of exercise programs on depression.
The current study was based on 2,051 patients with dementia from 20 RCTs with broad range of characteristics. Although significant heterogeneity was observed, we noted that the dementia patients who received exercise programs did not yield additional beneficial effects on cognition, ADL, and depression. Sensitivity analysis results indicated that exercise programs might play an important role in cognition and ADL. The beneficial effects of exercise programs on cognition were mainly observed in mean age of patients <80.0 years when compared with usual care and pooled low-quality studies. Moreover, we also noted that exercise programs could improve ADL when compared with usual care. These results are important for patients with dementia and warranted further large-scale RCTs to verify.
According to a previous systematic review based on 13 RCTs, AD patients receiving exercise programs showed positive effects on cognitive function, and 8/13 studies reported similar results, whereas the remaining 5 studies demonstrated no significant difference between exercise programs and control regarding cognitive function [
Although the pooled SMD indicated no significant difference between exercise programs and control in cognition, this result was not stable and a beneficial effect might be observed. Five of the included studies reported similar positive results, whereas 2 trials reported opposite conclusion [
Similarly, exercise programs did not yield additional beneficial effects on ADL, whereas a significant difference between exercise programs and control for ADL was observed. Most of the included studies reported no significant differences between exercise programs and control regarding the change in ADL, whereas de Souto Barreto et al. indicated that the levels of ADL in exercise group were lower than those in the control group [
However, our study has few limitations that should be mentioned. Firstly, the exercise strategy used by the included studies varied, and also the treatment effects of exercise programs differed. Secondly, the levels of cognition, ADL, and depression are evaluated by different scales in different studies, and substantial heterogeneity across the included studies was not fully interpreted. Thirdly, the type of dementia was not assigned in most of the included studies, and the analysis according to the types of dementia was not conducted. Fourthly, the summary results of depression were available in few studies and require verification in further studies. Fifthly, the analysis based on published studies and publication bias was inevitable. Finally, the detailed analysis was not conducted as this study used pooled data due to the unavailability of individual data.
In conclusion, these results suggested that exercise programs might play a beneficial role in cognition and ADL in patients with dementia, especially in younger patients and when compared with usual care, whereas exercise program showed no association with depression level. These results indicated that exercise programs should be introduced to patients with dementia, especially to younger patients. Further large-scale RCTs should be conducted to verify the treatment effects of exercise program on depression in patients with dementia.
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
The authors declare that they have no conflicts of interest.
This work was supported by the National Natural Science Foundation (Grant no. 31860598), and the Health Industry Research Project of Gansu Province (Grant no. GSWSKY2017-16).
Supplement 1: searching strategy in PubMed, Embase, and Cochrane. Supplement 2: it includes 3 figures as follows. Figure S1: sensitivity analysis for cognition. Figure S2: sensitivity analysis for ADL. Figure S3: sensitivity analysis for depression. Supplement 3: it includes 3 figures as follows. Figure S1: funnel plot for cognition. Figure S2: funnel plot for ADL. Figure S3: funnel plot for depression.