Aerobic exercise for older adults at increased risk of Alzheimer's and related dementias

Aerobic Exercise for Older Adults at Increased Risk of Alzheimer's Disease and Related Dementias: Harnessing Translational Physiology

This tests whether regular aerobic exercise, compared with stretching and strength sessions, can improve memory and brain blood flow in inactive adults aged 50–80 who have memory complaints and vascular risk factors.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 264 (estimated)
• Ages: 50 Years to 80 Years
• Sex: All
• Sponsor: University of Calgary (Academic / other)
• Locations: 1 site (Calgary, Alberta)
• Trial ID: NCT03035851 on ClinicalTrials.gov

What this trial studies

This interventional project assigns inactive adults aged 50–80 with self-reported memory complaints and one or more vascular risk factors to an aerobic exercise program or a stretching/strength program to compare effects on brain health. Investigators measure cognitive performance and cerebral blood flow and apply a translational physiology approach to explore biological mechanisms linking exercise to brain outcomes. The goal is to understand how exercise may prevent or slow age-related declines in cognition and brain function. Eligibility emphasizes subjective memory complaints, limited recent vigorous activity, and common vascular risk factors.

Who should consider this trial

Good fit: Ideal candidates are inactive men and women aged 50–80 with self-reported memory complaints (MAC-Q ≥25), at least one vascular risk factor, BMI under 40, no dementia, and who are cleared to begin an exercise program.

Not a fit: People with diagnosed dementia, those who are already regularly active at higher intensities, or individuals with unstable cardiovascular or other medical contraindications to exercise are unlikely to benefit from this intervention.

Why it matters

Potential benefit: If successful, the program could slow memory decline and improve brain blood flow and overall brain health in at-risk older adults.

How similar studies have performed: Prior randomized trials have reported modest improvements in cognition and vascular measures with aerobic exercise in older adults, but findings and mechanisms vary and are not fully settled.

Eligibility criteria

Inclusion Criteria:

* inactive men and women aged 50-80 years (inclusive) with subjective cognitive symptoms but no dementia who have one or more vascular risk factors (see below) for ADRD;
* Inactivity will be assessed with a physical activity questionnaire and defined as engagement in \<3 sessions/week of 20 min or more of vigorous exercise;
* Subjective cognitive symptoms will be self-reported using the MAC-Q Memory Complaint Questionnaire, recently validated as a measure of subjective memory complaints in healthy elderly subjects, in patients with mild cognitive impairment, and in relation to AD biomarkers; participants with a score of ≥25 will be considered eligible.
* Vascular risk factors for ADRD including the following:
* history of hypertension;
* diabetes mellitus;
* obesity (body mass index (BMI) \<40 kg/m2)
* elevated cholesterol;
* currently smoking;
* past history of coronary artery disease without recent (\<5 years) symptoms.

Participants must provide a completed PAR-Q+ form (www.csep.ca), the standard method of obtaining physician approval for participation in an exercise program. For participants without a family doctor to provide this form, we will provide information on how to find a family doctor.

Exclusion Criteria:

* diagnosis of a developmental handicap;
* history of dementia (DSM-V criteria)\*\*;
* terminal illness (life expectancy \< 1 year)
* not fluent in verbal and written English;
* history of stroke;
* currently participating in another trial;
* comorbid medical or neurological illnesses (e.g., multiple sclerosis) that would confound cognitive assessments or make trial completion unlikely (in the site investigator's opinion);
* contraindication for the intervention;
* contraindication for an MRI exam.
* \*\*Existing or suspected dementia will be identified by medical history, cognitive impairment on the Telephone Interview for Cognitive Status (TICS-modified; score≤ 20), or impaired Instrumental Activities of Daily Living (IADL) - a response of needs assistance or dependent due to cognitive impairments on any item on the Lawton scale.

Where this trial is running

Calgary, Alberta

• University of Calgary — Calgary, Alberta, Canada (Recruiting)

Study contacts

• Principal investigator: Marc J Poulin, PhD, DPhil — University of Calgary
• Study coordinator: Marc J Poulin, PhD, DPhil

Conditions Alzheimer Disease; Dementia; Exercise; Physical Activity; Brain blood flow; Cognition; Fitness