Understanding Cerebral Blood Flow Dynamics for Alzheimer's Disease Prevention Through Exercise (flADex)

Understanding Cerebral Blood Flow Dynamics for Alzheimer's Disease Prevention Through Exercise: the flADex Study

Dementia is one of the leading causes of disability worldwide. Underlying biological mechanisms are crucial in preclinical stages of Alzheimer's disease (AD). Alterations in cerebral blood flow (CBF) and their relationship with AD blood-based biomarkers may be fundamental at early stages of the pathology. Physical exercise is a trigger to modify these biological mechanisms. Therefore, flADex aims to examine the acute effects of different types of exercise (resistance vs. aerobic vs. control) on CBF, AD blood-based biomarkers, and its cognitive implications in older adults. The hypothesis is that acute resistance or aerobic exercise will fluctuate levels of blood-based biomarkers, and will exert acute CBF changes combined with cognitive implications.

Study Overview

• Status: Completed
• Conditions: Healthy Aging; Blood Flow; Cognitive Function 1, Social; Cerebrovascular Circulation
• Intervention / Treatment: Behavioral: Aerobic exercise condition; Behavioral: Resistance exercise condition

Detailed Description

The aging population is at an increasing risk of developing Alzheimer's Disease (AD), which is characterized by cognitive decline and memory loss. Current pharmacological treatments have targeted amyloid-beta (Aβ) and tau protein, and have largely failed to halt or reverse the progression of AD. This has led to a growing interest on examining additional underlying mechanisms responsible for the initiation of AD pathology in this preclinical stage, such as cerebral blood flow (CBF) alterations or peripheral levels of AD blood-based biomarkers. Parallelly, exercise might act as a trigger for these potential underlying mechanisms of AD in older adults. Thus, this study seeks to explore the acute effects of different type of exercise on CBF, blood-based biomarkers, and its cognitive implications in older adults.

FlADex is a counterbalanced crossover trial that will include 20 adults aged 68 to 83 with non-pathological brain amyloid status (<12 centiloid) and APOE e4 noncarriers. Each participant will be included in all study conditions in a randomized order: (i) moderate aerobic exercise (between 60-70 of the Maximal Heart Rate (HRmax); (ii); resistance exercise (4-6 Moderate intensity of Rate of Perceived Exertion) and (iii) control resting condition. Each condition, lasting 30 minutes, will be performed once. CBF will be assessed by magnetic resonance imaging using pseudo-continuous arterial spin labeling at pre-condition and at 3 consecutive times post-condition (at 20', 27' and 34' min). Blood-based biomarkers (Aβ42, Aβ40, p-tau217, p-tau181, GFAP, NfL, BDNF, IGF-1) will be measured pre-condition and post-condition (at 0', 50', 70' min). Cognitive outcomes (Flanker Test and Picture Sequence Memory Test) and mood status (feeling scale and POMS questionnaire) will be measured pre and post condition.

FlADex trial will shed light on the acute effects of different types of exercises on CBF and AD blood-based biomarkers before beta-amyloid accumulation. We expect that aerobic and resistance exercise will have different effects on CBF dynamics and AD blood biomarker levels over time in older adults

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Granada, Spain, 18011
    • Mind, Brain, and Behaviour Research Centre (CIMCYC, Centro de Investigación Mente, Cerebro y Comportamiento)
  • Andalucia
    • Granada, Andalucia, Spain, 18016
      • University of Granada

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Older adults
• Aged 68-83 years
• Non-pathological cerebral beta-amyloid status (based on Centiloid cut-point <12 measured by PET-CT)
• APOEe4 negative status
• Willingness to participate in exercise interventions

Exclusion Criteria:

• Pathological diagnosis related to physical or mental condition
• No living in community settings during the study
• MRI incompatibility
• Ambulatory with pain or regular use of an assisted walking device
• Severe cardiovascular or respiratory conditions
• Participation in another clinical trial within the last 30 days

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Aerobic exercise group; -Aerobic group. 30 min at 60-70% of the Maximal Heart Rate, moderate intensity on cycle.	Behavioral: Aerobic exercise condition; Aerobic session will last 30 min. The average intensity of the aerobic sessions will be 60-70% of the Maximal Heart Rate. Therefore, participant will perform a continuous moderate intensity aerobic bout of exercise on a cycle ergometer.
Experimental: Resistance exercise group; 30 min at 4-6 RPE (OMNI-Resistance Exercise Scale of Perceived Exertion), 3 sets of 8 exercise/set, 40 sec/exercise. Moderate intensity using elastic bands and body weight.	Behavioral: Resistance exercise condition; Resistance exercise will last 30 min at 4-6 RPE (OMNI-Resistance Exercise Scale of Perceived Exertion from 0-10). The bout of resistance exercise will include a combination of upper and lower body exercises using elastic bands and the participants' body weight as the primary resistance. Eight different exercises will be performed per set, with 40 seconds per exercise, for a total of 3 sets. The exercises are based on basic movement patterns and include: glute bridge, front plank, standing face pull, incline push-up, squat, pallof press, walking lunge and seated shoulder press.
No Intervention: Control; 30 min seated watching a neutral documentary without cognitive engagement

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Cerebral Blood Flow (CBF)	Specific acquisition parameters for Pseudo continuous Arterial Spin Labeling (pCASL) sequence are used to determinate global and regional CBF in resting condition. Structural T1 sequence (only pre-condition) is used to coregisted the pCASL and delineate regions of interest for CBF. Time-of-flight angiography (TOF) (before pCASL pre-condition and before first pCASL post-condition) sequence is used to identify the carotid arteries. The unit of measurement of the CBF is expressed as milliliters per 100 grams of brain tissue per minute (mL/100 g/min).	30 minutes before the experimental condition; and 20 minutes, 27 minutes and 34 minutes minutes after the experimental condition

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Alzheimer disease blood-based biomarkers (Aβ42/40 ratio)	The following biomarkers will be assessed: Amyloid-beta 42 (Aβ42), Amyloid-beta 40 (Aβ40). Aβ42 and Aβ40 will be combined to report Aβ42/40 ratio. Unit of measurement: Aβ42/40 is a ratio (no units) and represents the relative concentration of Aβ42 to Aβ40.	5 minutes before the experimental condition; and 0 minutes, 50 minutes and 70 minutes after the experimental condition
Change in Alzheimer disease blood-based biomarkers (p-tau217, p-tau181, NfL and GFAP)	The following biomarkers will be assessed: phosphorylated tau protein at positions 217 and 181 (p-tau217, p-tau181), Glial Fibrillary Acidic Protein (GFAP) and Neurofilament Light Chain (NfL). Unit of measurement: p-tau217, p-tau181, NfL and GFAP are commonly measured in picograms per milliliter (pg/mL).	5 minutes before the experimental condition; and 0 minutes, 50 minutes and 70 minutes after the experimental condition
Change in growth factors (BDNF)	Brain-Derived Neurotrophic Factor (BDNF) will be measured. Unit of measurement: BDNF is commonly measured in picograms per milliliter (pg/mL).	5 minutes before the experimental condition; and 0 minutes, 50 minutes and 70 minutes after the experimental condition
Change in growth factors (IGF-1)	Insulin-Like Growth Factor 1 (IGF-1) will be measured. Unit of measurement: IGF-1 is commonly measured in nanograms per milliliter (ng/mL).	5 minutes before the experimental condition; and 0 minutes, 50 minutes and 70 minutes after the experimental condition
Change in episodic memory	Episodic memory will be assessed using the Picture Sequence Memory Test from the Cognitive NIH Toolbox. The Cognitive NIH Toolbox is a computer-based battery which is available in Spanish. The Picture Sequence Memory Test measures episodic memory by deriving the participant's score from the cumulative number of adjacent pairs of pictures remembered correctly over two learning trials. The variable used for the for the PSMT is the theta score: The number of adjacent pairs placed correctly for each of trials 1 and 2 is converted to a theta score. This is a representation of the given participant estimated ability in the task.	15 minutes before the experimental condition; and 60 minutes after the experimental condition
Change in inhibition/attention	The Flanker task measures inhibitory control and attention by using the inverse efficiency score of incongruent trials. The inverse efficiency score is calculated as reaction time/accuracy (RT/ACC).	15 minutes before the experimental condition; and 60 minutes after the experimental condition
Mood status	Mood status will be evaluated using the validated scale Profile of Mood States (POMS). The POMS scale is a psychological assessment tool used to measure and evaluate a person's mood states. It consists of a questionnaire with a list of 15 adjectives or mood descriptors, where individuals rate how they have been feeling on a scale typically ranging from "Not at all" to "Extremely". We use an abbreviated version of the scale with 15 ítems. The ítems are divided into 5 dimensions: depression, vigour, anger, tension and fatigue. The final score is: ([depression]+[anger]+[tension]+[fatigue]) - [vigour].	POMS will be measured 60 minutes before the experimental condition; and 70 minutes after the experimental condition
Feeling scale	Emotional response will be evaluated using the feeling scale (FS). The FS is an 11-point scale ranging from -5 (very bad) to +5 (very good) used to measure an individual's emotional feeling in terms of pleasure or displeasure at a specific moment.	Feeling scale will be measured 1 minute before the experimental condition; and 1 minute after the experimental condition

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Enjoyment	Enjoyment of Physical activity will be assessed using the Physical activity Enjoyment scale (PACES): The PACES is an 18-item scale but we will use the reduced and validated version of 8 items, assessing in a range of 1 to 7 a series of sensations or moods with respect to its opposite, so that it is easier and more practical for participants.	5 minutes after the experimental condition
Physical engagement (in aerobic condition and resistance condition)	Perceived exertion of exercise (RPE) will be assessed using the OMNI-Resistance Exercise Scale (OMNI-RES) of perceived exertion from 0-10.	During the experimental condition at minute 12, minute 20, and minute 30
Repetitions in reserve (in resistance condition)	The Repetitions in Reserve (RIR) will be assessed after each exercise in the resistance condition. RIR method is a self-regulation technique used in strength training to gauge exercise intensity. It involves estimating how many more repetitions you could perform before reaching failure after completing a set.	During the resistance condition after each exercise at minutes 5, 6, 7, 8, 9, 10, 11, 12 / 14, 15, 16, 17, 18, 19, 20, 21 / 23, 24, 25, 26, 27, 28, 29, 30
Cognitive engagement	Cognitive engagement will be assessed by the Cognitive Load Measurement scale. The Cognitive Load Scale is a 9 ítem scale used to assess the mental effort or cognitive load experienced by individuals when engaging in a task, particularly in educational or learning contexts. It involves a self-reported measure where participants rate their perceived mental effort on a scale, ranging from 1 very low mental effort; to 9 very high mental effort.	During the experimental condition at minute 12, minute 20, and minute 30

Collaborators and Investigators

• Sponsor: Universidad de Granada
• Collaborators: University Hospital Virgen de las Nieves; Instituto Mixto Universitario Deporte y Salud (iMUDS); Centro de Investigación Mente, Cerebro y Comportamiento
• Investigators: Principal Investigator: Irene Esteban-Cornejo, PhD, Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Spain.

Publications and helpful links

Helpful Links

• Detailed information about the protocols, methodology , data analysis, and code used in this project will be upload to the GitHub repository: FLADEX Project GitHub Repository.

Study record dates

Study Major Dates

• Study Start (Actual): September 25, 2024
• Primary Completion (Actual): January 2, 2025
• Study Completion (Actual): January 2, 2025

Study Registration Dates

• First Submitted: August 6, 2024
• First Submitted That Met QC Criteria: September 1, 2024
• First Posted (Actual): September 5, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 24, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Exercise; Alzheimer's Disease; Magnetic resonance imaging; Aging; Biomarkers; Cerebral Blood Flow
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Neurocognitive Disorders; Dementia; Tauopathies; Neurodegenerative Diseases; Alzheimer Disease
• Other Study ID Numbers: PID2022-137399OB-I0

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The protocol, statistical analyses plan and data management plan will be sharing open access. Data files including IPD, and corresponding data dictionaries, will be shared under restricted access and upon reasonable request (contact Irene Esteban-Cornejo) due to privacy issue and GDPR regulations. In principle, all collected IPD will be available for sharing under the "as open as possible, as closed as necessary" principle. The shared data files will be pseudonymized, only include participants who provided informed consent for sharing, and sharing is only possible when the data is used for research purposes regarding exercise, and brain health. This is stated at the informed consent files that the participants signed when they agree to participate.
• IPD Sharing Time Frame: The IPD data will be available 12 months after the primary outcome paper published. The data will be available 15 years after data collection.
• IPD Sharing Access Criteria: The specific process of data access will be determined in a later stage, but in general the research team supports data sharing. Roughly, data will be available upon reasonable request to the PI (Irene Esteban-Cornejo). The data requests must contain the purpose and aim of the research, but also specification of the data requested, and data analysis before data sharing. Data will only be shared for research purposes on exercise and brain health. In addition, we will follow "as open as possible, as closed as necessary" principle, so depending on this principle we will decide whether the data could be shared. A data access committee will be installed to approve data requests.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No