Effects of low- and high-intensity physical exercise on physical and cognitive function in older persons with dementia: a randomized controlled trial

Abstract

Background: Potential moderators such as exercise intensity or apolipoprotein-E4 (ApoE4) carriership may determine the magnitude of exercise effects on physical and cognitive functions in patients with dementia (PwD). We determined the effects of a 24-week aerobic and strength training program with a low-and high-intensity phase on physical and cognitive function. Methods: In an assessor-blinded randomized trial, 91 PwD (all-cause dementia, recruited from daycare and residential care facilities, age 82.3 ± 7.0 years, 59 women, Mini-Mental State Examination 20.2 ± 4.4) were allocated to the exercise or control group. In the exercise group, PwD participated in a walking and lower limb strength training program with 12 weeks low-and 12 weeks high-intensity training offered three times/week. Attention-matched control participants performed flexibility exercises and recreational activities. We assessed adherence, compliance, and exercise intensity for each session. We assessed physical (endurance, gait speed, mobility, balance, leg strength) and cognitive (verbal memory, visual memory, executive function, inhibitory control, psychomotor speed) functions with performance-based tests at baseline and after 6, 12, 18, 24, and 36 weeks (follow-up). ApoE4 carriership was determined post-intervention.Results: Sixty-nine PwD were analyzed. Their mean attendance was~60% during the study period. There were no significant effects of the exercise vs. control intervention on endurance, mobility, balance, and leg strength in favor of the exercise group (Cohen's d = 0.13-0.18). Gait speed significantly improved with~0.05 m/s after the high-intensity phase for exercise participants (Cohen's d = 0.41) but declined at follow-up. There were no significant effects of the exercise vs. control intervention on any of the cognitive measures (Cohen's d~− 0.04). ApoE4 carriership did not significantly moderate exercise effects on physical or cognitive function.(Continued on next page) Conclusions: Exercise was superior to control activities for gait speed in our sample of PwD. However, the training effect provided no protection for mobility loss after detraining (follow-up). There were no beneficial effects of the exercise vs. control group on cognitive function. Exercise intensity moderated the effects of exercise on gait speed. ApoE4 carriership moderated the effect of exercise on global cognition only (trend level).

Effect of physical exercise on cognitive function in older adults’ carriers versus noncarriers of apolipoprotein E4: systematic review and meta-analysis

“…Barnard et al (2014) states that adopting 40 min of fast walking 3 times a week as routine physical exercise can improve cognitive function. However, in our study we can observe that performing 30 min 3 times per week of physical exercise can also improve the cognitive functions of the older adult (Sanders et al, 2020) this follows the line of other studies (Jia et al, 2019) where it is stated that performing physical exercise up to 30 min per week improves the cognitive condition of patients. Based on our results, we could say that older people who do not carry out ApoE4 should perform 150 min per week of physical exercise, with a minimum of 50 sessions in order to perceive positive benefits over cognitive functions.…”

High-intensity exercise programs in people with dementia — a systematic review and meta-analysis

“…Qualitative analyses of physical performance outcome parameters did not reveal major differences in favour of HIT, neither in mobility nor in lower-extremity muscle strength. However, several interaction analyses conducted as part of the UMDEX study by Toots et al (2017b) showed superior effects on GS in favour of the HIT groups, if the participants were able to walk independently during the 6-metre walking test which is in line with the results of Sanders et al (2020). Nevertheless, 78% of the UMDEX and 68% of the EXDEM study participants (Telenius et al, 2015a(Telenius et al, , 2015b were unable to walk without support.…”

“…The selection of English publications only could be another source of publication bias. Unfortunately, we had a lag time bias since we did not include a recent and relevant RCT from Sanders et al (2020) in our review. Since we could not identify any published study protocols a selective reporting assessment was not feasible.…”

Exercise as Potential Therapeutic Target to Modulate Alzheimer’s Disease Pathology in APOE ε4 Carriers: A Systematic Review

“…Physical activity was assessed with a survey in combination with data obtained from a pedometer to avoid bias. This study demonstrated that [27]. Methods used to quantify the physical activity in this study were highly variable among patients with dementia.…”

“…Additional analysis revealed that APOE ε4 non-carriers in the intervention group scored better on the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) test compared to carriers and controls, as expected. On the contrary, a recent study by Sanders et al showed that a 24-week aerobic exercise program did not modify cognitive function in APOE ε4 carriers with dementia [ 27 ]. Methods used to quantify the physical activity in this study were highly variable among patients with dementia.…”