Effects of physical activity training in patients with Alzheimer's dementia: results of a pilot RCT study

Abstract

Background: There is evidence that physical activity (PA) is of cognitive benefit to the ageing brain, but little is known on the effect in patients with Alzheimer's disease (AD). The present pilot study assessed the effect of a home-based PA training on clinical symptoms, functional abilities, and caregiver burden after 12 and 24 weeks.

Methods: In an RCT thirty patients (aged 72.4±4.3 years) with AD (MMSE: 20.6±6.5 points) and their family caregivers were allocated to a home-based 12-week PA intervention program or the usual care group. The program changed between passive, motor-assisted or active resistive leg training and changes in direction on a movement trainer in order to combine physical and cognitive stimuli.

Results: Analysis of activities of daily living in the patients (ADCS ADL total score) revealed a significant group × time interaction effect (95% CI of the difference between both groups at T2: 5.01-10.51). The control group experienced decreases in ADL performance at week 12 and 24 whereas patients in the intervention group remained stable. Analyses of executive function and language ability revealed considerable effects for semantic word fluency with a group × time interaction (95% CI of the difference between both groups at T2: 0.18-4.02). Patients in the intervention group improved during the intervention and returned to initial performance at week 12 whereas the controls revealed continuous worsening. Analyses of reaction time, hand-eye quickness and attention revealed improvement only in the intervention group. Caregiver burden remained stable in the intervention group but worsened in the control group.

Conclusions: This study suggests that PA in a home-based setting might be an effective and intrinsically attractive way to promote PA training in AD and modulate caregiver burden. The results demonstrate transfer benefits to ADL, cognitive and physical skill in patients with AD.

Trial registration: ClinicalTrials.gov NCT02196545.

Conflict of interest statement

Competing Interests: This funding did not imply competing interests and was restricted to the technical support and delivery to and from the participants’ homes. There was no further commercial assistance, no employment, consultancy, patents or products in development, marketed products or marketing implied in this sponsoring. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. All authors state that there are no competing interests that could interfere with the complete and objective presentation of the study results.

Figures

Fig 1. Consort Flow Chart.

Fig 2. a-e. Effects of physical activity on clinical performance.

This figure shows the effects of physical activity on the patients when compared to the control group for the three time points (T0- baseline, T1–3 months later or after completion of the intervention and T2- 3 month follow-up). Activities of daily living (ADCS ADL total scores): patients in the control group experienced significant decreases in their performance over 12 weeks and at the 3 month follow-up whereas patients in the intervention group remained stable during the study period and follow-up (Fig 2a). Neuropsychiatric symptom profiles (NPI total scores): controls suffered a considerable increase in behavioural changes over 24 weeks whereas patients in the intervention group remained stable over 24 weeks (Fig 2b). Executive function and language ability: patients in the intervention group improved during the intervention period and returned to initial performance after completion but without revealing the continuous worsening over 24 weeks demonstrated in the controls (Fig 2c). Reaction time, hand-eye quickness and attention (FETZ-test or Ruler Drop Test): only patients in the intervention group improved their performance during the study period (Fig 2d). Caregiver burden (NPI): burden increased in the control group during the first 3 months whereas caregiver burden remained stable in the intervention group during the study period (Fig 2e).