About this trial
The goal of this 26-week trial is to learn if creatine supplementation and resistance training (i.e., weightlifting; exercise that increases muscle mass), alone and together, impact cognition, brain health, and physical function in older adults with mild cognitive impairment. Previous studies have shown that resistance training improves cognition and brain health in older adults. Creatine is naturally occurring in the human body and is known to decline with age. Studies have shown that creatine increases muscle mass and bone density in older adults when supplemented. Some research has suggested that creatine may also improve cognition and brain health. However, little is known about how creatine supplementation affects the aging brain and body alone and when combined with resistance training, especially in those with known cognitive impairment.
In this study, participants will be randomly assigned to one of four groups: 1) creatine and resistance training, 2) placebo and resistance training, 3) creatine and active control (balance and tone classes), or 4) placebo and active control. Participants in the creatine groups will take creatine every day during the study. Participants in the placebo groups will take a look-alike substance that contains no drug every day during the study. Participants in the resistance training groups will attend three 60-minute classes per week that target each major muscle group and will increase in difficulty during the study. Participants in the active control group will attend three 60-minute classes per week that will consist of balance, stretching, and range of motion exercises. This group accounts for variables such as physical training received by traveling to the training centres, social interaction, and changes in lifestyle secondary to study participation.
Researchers will collect information before and after the 26 weeks to see if creatine supplementation and/or resistance training have any effects on cognition, brain health, and/or physical function. The investigators suspect that both creatine supplementation and resistance training will improve cognition, brain health, and physical function alone. However, it is thought that the combination of creatine supplementation and resistance training will improve cognition, brain health, and physical function more.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
None
Disqualifiers
None
Trial design
Factorial
Treatments tested in this trial
Creatine monohydrate
Dietary supplementParticipants will consume one serving of creatine daily (0.10g of creatine/kg of body weight). This relative dosing approach ensures that smaller participants do not receive excessive doses, while larger participants receive an adequate amount. There is currently limited evidence to conclude the effectiveness of timing daily creatine intake, but it is recommended that creatine be consumed at mealtime for optimal absorption. Participants will choose what meal they will take the supplement and will be asked to keep timing consistent throughout the study. This daily low dose method was chosen because other methods (high-dose loading) may have negative side effects (e.g., water retention, cramping). The trial duration is also enough time to entire creatine saturation with supplementation.
Resistance training
BehavioralParticipants will use the programmable weight machines along with free weights to target primary muscle groups. In addition, they will complete mini-squats, mini-lunges, and lunge walks. Participants will complete two sets of 6-8 reps. Training stimulus will be increased using the 7RM method - when 2 sets of 6-8 reps are completed with proper form and without discomfort. The investigators will record the number of sets completed and the load lifted for each exercise for each participant at every class.
Treatment groups
Trial outcomes
Primary outcomes
Corsi Span - Corsi Block Tapping Task
Visuospatial working memory will be assessed using the forward and reverse Corsi block-tapping task. Participants will be given an iPad to complete the task. In this task, participants will see nine BLUE blocks on the screen. For each trial, a sequence of blocks will turn RED one by one. Their task is to remember the order in which the blocks light up and then repeat the sequence in the same order (forward Corsi) or backwards (reverse Corsi) by tapping on the blocks. Participants will first complete two practice trials before the true trials to ensure that the instructions are understood. Sequences will become increasingly more difficult with a maximum sequence of nine and a minimum of two. The maximum sequence number that each participant correctly reproduces (Corsi span) will be measured, where higher scores indicate better visuospatial working memory.
Reaction Time - Corsi Block Tapping Task
Visuospatial working memory will be assessed using the forward and reverse Corsi block-tapping task. Participants will be given an iPad to complete the task. In this task, participants will see nine BLUE blocks on the screen. For each trial, a sequence of blocks will turn RED one by one. Their task is to remember the order in which the blocks light up and then repeat the sequence in the same order (forward Corsi) or backwards (reverse Corsi) by tapping on the blocks. Participants will first complete two practice trials before the true trials to ensure that the instructions are understood. Sequences will become increasingly more difficult with a maximum sequence of nine and a minimum of two. Reaction time, or how fast the participant can reproduce each sequence, will be measured.
Secondary outcomes
Interference Score - Stroop Task
Investigators will examine the interference score for each participant using the Stroop task. Participants are required to read the colour of the ink that each word is printed in and inhibit what the word actually says. The time to complete this test is recorded in seconds. Higher scores reflect better performance and less interference.
Span Capacity - Digits Forward and Backward Subtests
Working memory using the Digits Forward and Backward subtests. Participants are required to memorize and recall a series of number lists both forward and backward. Span capacity (the largest sequence to be recalled) will be measured. The minimum sequence for the forward test is three and the maximum is nine. The minimum sequence for the backward test is two and the maximum is eight. Higher sequences reproduced indicate better working memory.
Time - Trail Making Test (Part B)
Mental flexibility using the Trail Making Test (Part B). Participants will have to alternate between numbers and letters without removing the pen from the page. The time to complete this test is recorded in seconds.
Memory Score - Rey Auditory Verbal Learning Test
Participants are read a list of 15 words five times and asked to recall verbally as many as possible. They are then given a separate (interference) list of words and then need to recall the original list immediately after (immediate recall 0 and again after a 20-minute delay (delayed recall).
Other outcomes
Hippocampal Volume - Structural MRI
Hippocampal volume will be examined in a sub-set of participants using MRI. Participants will undergo structural MRI on the 3T Siemens scanner at the Centre for Functional and Metabolic Mapping (CFMM) on Western University campus. Participants will complete T1 and T2 high resolution anatomical scans.
Structural Integrity - Structural MRI
Structural integrity will be examined in a sub-set of participants using MRI. Participants will undergo diffusion tensor imaging (DTI) on the 3T Siemens scanner at the Centre for Functional and Metabolic Mapping (CFMM) on campus. DTI allows for evaluation of microstructures in the brain by measuring water movement.
Resting State Functional Connectivity - Functional MRI
Participants will be asked to remain as still as possible with eyes closed while a 12-minute functional scan is performed. This will allow the investigators to examine activation in the resting state network.
Proton Magnetic Resonance Spectroscopy (1H-MRS) and Chemical Exchange Saturation Transfer (CEST) - Functional MRI
These advanced metabolic MRI techniques provide information on metabolic activity in the brain. Creatine concentrations in the brain will be measured using 1H-MRS and CEST. Key metabolite concentrations, including N-acetylaspartate, creatine, choline and myo-inositol will be evaluated using 1-H MRS at 3T in a 2cm voxel in the posterior cingulate cortex. Regional variation in creatine levels will be evaluated using a CEST based technique to measure free creatine.
Sponsors and contacts
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Western University, Canada
Lead sponsor
Alzheimer Society of Canada
Collaborator