Effectiveness of Walking Exercise in Improving Cognitive Function in Older Adults With Mild Cognitive Impairment

The University of Hong Kong (HKU)

Status: Completed

Conditions: Mild Cognitive Impairment

Treatments: Behavioral: Low-frequency, moderate-intensity walking group; Behavioral: High-frequency, moderate-intensity walking group; Behavioral: Low-frequency, vigorous-intensity walking group; Behavioral: High-frequency, vigorous-intensity walking group; Behavioral: Stretching exercise

Study type: Interventional

Funder types: Other

Identifiers

NCT04515563

RF-3030059835-007

Details and patient eligibility

About

The increasing prevalence of mild cognitive impairment (MCI) in our rapidly aging population prompts the need for devising effective interventions to prevent the onset of cognitive impairment and delay its progression to dementia. The benefits of aerobic exercise on the cognitive function in older adults with MCI are well-documented. However, exercise protocols and outcome measurement tools in the current literature are highly heterogeneous. It is therefore imperative to develop standard exercise prescription protocol for the MCI population or to examine the effectiveness of the existing, well-established exercise guidelines. The World Health Organization (WHO) recommends adults (18 - 64 years of age) and older adults (65 years and older) to perform 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic physical activity per week to improve cardiorespiratory and muscular fitness, bone health, and reduce the risk of non-communicable diseases and depression. Nonetheless, few studies have determined the effectiveness of the WHO Global Recommendations on Physical Activity for Health guideline in improving cognitive function in older adults with MCI. This study thus aims to evaluate the effectiveness of the WHO Physical Activity Recommendations in improving cognitive function in older adults with MCI. In 2017, the American Academy of Neurology (AAN) updated the Practice Guideline for Mild Cognitive Impairment, in which they recommended patients diagnosed with MCI to perform exercise at least twice a week for at least 6 months to gain cognitive benefits. This recommendation was based on two class-II studies, in which a 6-month twice-a-week 90-minute multicomponent exercise program helped maintain global cognition, and selective attention improved significantly following a 6-month twice-a-week 60-minute multicomponent exercise program. While they provided pivotal insights into clinical practice, there were several limitations for these two studies. For instance, in the study conducted by Nagamatsu et al., only female subjects were recruited, and therefore lead to low generalizability. These two studies focused on multi-component exercise intervention which included resistance training, aerobic training, and balance training, and the duration of each component was short (around 20 - 30 minutes). Studies that focus on single exercise modality with longer session duration are warranted to unveil the efficacy of a certain exercise modality in improving cognitive function. In this study, we will evaluate the effectiveness of aerobic exercise on improving cognitive function in older adults with MCI. We intend to follow the WHO Recommendations, focusing on evaluating the effect of different exercise intensities (moderate versus vigorous) and frequencies (once versus thrice per week) of aerobic exercise on improving the cognitive function in older adults with mild cognitive impairment. In particular, the AAN also suggested that physical activity of at least twice a week is necessary to produce cognitive benefits. We, therefore, aim to investigate whether one session per week would also suffice to improve the cognitive function in older adults with MCI.

Aims: To examine the effectiveness of 12-week WHO Global Recommendations on Physical Activity for Health in practice in improving the cognitive function in older adults with MCI.

Enrollment: 50 patients

Sex: All

Ages: 50+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Older adults aged ≥ 50 years old;
2. Ethnic Chinese;
3. Diagnosed with mild cognitive impairment (MCI) under the Mayo Clinic criteria [8-10]: 1). Subjective complaint about a decline in cognitive function; 2). Total score in the Hong Kong version of the Montreal Cognitive Assessment is below the 7th percentile of the age- and education-corrected normative data of Hong Kong; 3). The decline in cognitive function does not impair daily functioning, as revealed by getting ≥ 2 marks in every item on the Chinese Lawton Instrumental Activities of Daily Living Scale (4-point Scale).

Exclusion criteria

1. Diagnosis of dementia/Alzheimer's disease, or currently using antidementia medication;
2. Incapable of participating in physical exercise with major confounding conditions that are known to affect mobility. Specifically designed questionnaires will be used to screen for exclusion criteria including 1). Cannot walk without assistive device; 2). Any serious somatic condition that prevents walking exercise participation.
3. History of major diseases e.g. cancer, cardio-/cerebrovascular, neurodegenerative and renal diseases;
4. Diagnosis of psychiatric diseases, or currently using psychiatric medication.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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50 participants in 5 patient groups, including a placebo group

Control Group

Placebo Comparator group

Description:

Subjects in the care control group will perform once-a-week stretching exercise intervention. Each session lasts for 75 minutes and covers the major muscle groups.

Treatment:

Behavioral: Stretching exercise

Low-frequency, moderate-intensity walking group

Experimental group

Description:

A personalized walking exercise program will be arranged and conducted individually. Exercise training will be prescribed as a 12-week program, with one 150-minute instructor-led session per week. In each session, there will be 5-min warm-up and cool-down, and 150 minutes of exercise time. If needed, there will be two 10-20 min breaks for the subject to get hydrated and rest. The intensity level will be set to 3.5 metabolic equivalents (METs), in which 1 MET refers to the metabolic rate during quiet sitting \[23\]. During the training session, the heart rate will be continuously monitored by Polar E68 HR Sensor to make sure the subject meet the exercise intensity. 10 bpm fluctuation of the heart rate is acceptable \[24\].

Treatment:

Behavioral: Low-frequency, moderate-intensity walking group

High-frequency, moderate-intensity walking group

Experimental group

Description:

Intervention of high-frequency, moderate-intensity walking exercise will be given to subjects in this group. A personalized walking exercise program will be arranged and conducted individually. Exercise training will be prescribed as a 12-week program, with three 50-minute instructor-led sessions per week. In each session, there will be 5-min warm-up and cool-down, and 50 minutes of exercise time. If needed, there will be one 10-20 min break for the subject to get hydrated and rest. The intensity level will be set to 3.5 metabolic equivalents (METs), in which 1 MET refers to the metabolic rate during quiet sitting \[23\]. During the training session, the heart rate will be continuously monitored by Polar E68 HR Sensor to make sure the subject meet the exercise intensity. 10 bpm fluctuation of the heart rate is acceptable \[24\].

Treatment:

Behavioral: High-frequency, moderate-intensity walking group

Low-frequency, vigorous-intensity walking group

Experimental group

Description:

Intervention of low-frequency, vigorous-intensity walking exercise will be given to subjects in this group. A personalized walking exercise program will be arranged and conducted individually. Exercise training will be prescribed as a 12-week program, with one 75-minute instructor-led session per week. In each session, there will be 5-min warm-up and cool-down, and 75 minutes of exercise time. If needed, there will be two 10-20 min breaks for the subject to get hydrated and rest. The intensity level will be set to 7.0 metabolic equivalents (METs), in which 1 MET refers to the metabolic rate during quiet sitting \[23\]. During the training session, the heart rate will be continuously monitored by Polar E68 HR Sensor to make sure the subject meet the exercise intensity. 10 bpm fluctuation of the heart rate is acceptable \[24\].

Treatment:

Behavioral: Low-frequency, vigorous-intensity walking group

High-frequency, vigorous-intensity walking group

Experimental group

Description:

Intervention of high-frequency, vigorous-intensity walking exercise will be given to subjects in this group. A personalized walking exercise program will be arranged and conducted individually. Exercise training will be prescribed as a 12-week program, with three 25-minute instructor-led sessions per week. In each session, there will be 5-min warm-up and cool-down, and 25 minutes of exercise time. If needed, there will be a 10-20 min break for the subject to get hydrated and rest. The intensity level will be set to 7.0 metabolic equivalents (METs), in which 1 MET refers to the metabolic rate during quiet sitting \[23\]. During the training session, the heart rate will be continuously monitored by Polar E68 HR Sensor to make sure the subject meet the exercise intensity. 10 bpm fluctuation of the heart rate is acceptable \[24\].

Treatment:

Behavioral: High-frequency, vigorous-intensity walking group