Research objectives:
To evaluate the effects of 26 weeks of creatine supplementation on its own and in
combination with progressive resistance training in community-dwelling older adults with
mild cognitive impairment on:
visuospatial working memory (primary objective);
executive function (working memory, inhibitory control, and mental flexibility),
functional mobility, muscle and grip strength, bone density, and blood-based
biomarkers for brain health and cognitive decline (secondary objectives); and
resting state functional activity, hippocampal volume and structural integrity, and
key metabolite concentrations in the brain (exploratory objective).
Hypotheses:
It is hypothesized that 26 weeks of creatine supplementation and resistance training in
community-dwelling older adults with mild cognitive impairment will: 1) increase
visuospatial working memory performance; 2) improve executive function, functional
mobility, strength performance, bone density, and blood-based biomarkers for brain health
and cognitive decline; and 3) increase resting state functional activity, volume and
structural integrity in the hippocampus, and concentrations of key metabolites in the
brain.
The investigators hypothesize that both creatine supplementation and resistance training
will improve our outcome measures independently. Moreover, the investigators hypothesize
that their combined application will yield superior improvements compared to their
individual effects.
Methods:
Screening: Participants interested in the study will reach out to us via phone or e-mail.
Interested participants will be sent the study Letter of Information via e-mail to get
more detailed information. At the time of study enrolment, interested participants will
be screened over the phone to assess for eligibility prior to scheduling their baseline
session. At this time, participants will have an opportunity to ask questions.
Eligibility will be confirmed by the following:
Telephone version of the Montreal Cognitive Assessment (T-Moca) that assesses
cognitive impairment status. Participants must obtain <19/22.
Instrumental Activities of Daily Living (IADL) questionnaire, which is a clinical
assessment used to measure an individual's ability to perform tasks necessary for
living independently in the community. Participants must obtain >6/8.
Geriatric Depression Scale (GDS). Participants must obtain <5 on the GDS. Those who
are eligible and still interested in participating will be scheduled to come into
the lab for baseline assessments.
Baseline assessments: When participants arrive in the lab, the researcher will go over
the consent form with them, answer any additional questions they have about the study,
and obtain informed written consent. At this time, participants may also consent to
participate in the optional MRI portion of this study. Participants will then complete
baseline assessments. Total time to complete baseline assessments in the lab (excluding
MRI) will be ~2.5-3 hours. For those participating in the MRI component, this will be
scheduled for another separate visit (1 hour).
Randomization: Once participants complete baseline assessment, they will be randomly
assigned to one of the four conditions. Group allocation will be determined using the
Clinical Trial Randomization tool, developed by the National Cancer Institute. The
sequence will be held remotely by the PI and will not be revealed until after baseline
assessments.
Descriptors and covariates:
Anthropometry (height, weight) will be measured at baseline. Weight will be
collected at midpoint to adjust dietary supplementation according to body weight, if
needed.
Demographic information (e.g., age, sex, gender, ethnicity, education, socioeconomic
status) will be collected at baseline.
Global cognitive function (T-MoCA; Mini-Mental Status Examination, MMSE). T-MoCA is
used as a screening tool for mild cognitive impairment. This test assesses cognitive
ability in the domains of attention and concentration, executive functions, memory,
language, visuo-constructional skills, conceptual thinking, calculations, and
orientation. The maximum score is 22 on the telephone version. The MMSE is used as a
screening tool for cognitive impairment. This 11-item test assesses global cognitive
function in the domains of orientation, registration, attention and calculation,
recall, and language with a maximum score of 30. The MoCa will be administered
during screening and at endpoint. The MMSE will be administered at baseline and
endpoint.
Physical activity levels (Physical Activities Scale for the Elderly, PASE). Used to
measure the level of self-reported physical activity, and consists of 12 questions
about leisure, household, and work-related daily activity. The PASE will be
administered at baseline and endpoint, as well as monthly at the last exercise
session of every month to assess physical activity habits outside of the
intervention.
Mood (GDS).The GDS is a 15-item questionnaire used to test for the presence of
depression. It will be administered at screening and endpoint. If depression is
suspected, the PI will ensure that the participant is provided with a copy of the
questionnaire and will advise the participant to make an appointment with their
family physician to discuss the results. It will be administered during screening
and at endpoint.
Number of co-morbidities (Functional Comorbidity Index, FCI). The FCI is an 18-item
list of diagnoses used to determine co-morbidities. It will be administered at
baseline and at endpoint.
Health-related quality of life (Short Form Health Survey, SF-12). A self-report
measure examining eight domains: vitality, physical functioning, bodily pain,
general health perceptions, physical role functioning, emotional role functioning,
social role functioning, and mental health. Scores range from 0-100, with higher
scores indicating greater health status and quality of life. It will be administered
at baseline and endpoint.
Loneliness (UCLA Loneliness Scale). A 20-item self-report measure on loneliness and
interpersonal problems. It will be administered at baseline and endpoint.
Independence (IADL questionnaire). An 8-item self-report measure about everyday
tasks. It will be administered during screening and at endpoint.
Behaviour (Capability, Opportunity, Motivation Behaviour Physical Activity
Questionnaire, COM-B PAQ; Motivation to Change Lifestyle and Health Behaviours for
Dementia Risk Reduction, MCLHB-DRR). The COM-B PAQ has 6-items measured on a
10-point Likert scale and assesses behaviour in the domains of capability,
opportunity, and motivation. The MCLHB-DRR is a 27-item questionnaire measured on a
5-point Likert scale. Items are used to assess behaviour in the domains of perceived
susceptibility, benefits, barriers, cues to action, general health motivation and
self-efficacy. These questionnaires will be administered at baseline.
Dietary intake (Three Day Weighed Food Record). Used to assess nutrient and energy
intake. Participants will record their dietary consumption over three days (two
weekday and one weekend day). They will be instructed on how to do the food record
at the end of the baseline session and will be asked to return it by their first
exercise session. A dietetic student will assist in analysing this data.
Real-time physical activity levels (ActiGraph ambulatory monitoring wearables).
Participants will be given the accelerometer to wear on their non-dominant wrist at
baseline for one week prior to the intervention and endpoint for week after the
intervention. Our lab has 10 devices, so up to 10 participants can have access to a
device simultaneously. This will allow objective quantification of energy
expenditure, metabolic equivalent of task rates, steps, physical activity intensity,
sedentary bouts, and sleep latency. To support validation of Actigraph-derived sleep
measures, participants will also complete a brief written sleep diary during each
wear period to capture self-reported sleep timing and related sleep characteristics.
They are Bluetooth enabled for real-time data uploads and include a wear-time sensor
to assess compliance.
Adherence: All participants will be asked to record their supplement consumption on a
monthly calendar, which will be returned to the lab at end of each intervention month.
This monthly calendar will also track exercise attendance and falls during the month.
Participants will also receive their supplement container at the beginning of each month
and will be asked to return the container with all the sachets to track adherence.
Exercise class attendance will be recorded each session by instructors. Participants will
be encouraged to adhere to both the supplement protocol and exercise classes. The
investigators will implement the following strategies to promote participant engagement:
Semi-monthly newsletters that will feature personal accomplishments of participants
(with permission) and study updates, for example.
Investigators will follow up with participants who have missed supplement doses or
exercise sessions to discuss barriers and strategies to overcome them on an
individual basis.
If participants miss classes due to illness/travel, they will be scheduled to make up
missing classes as soon as possible. If participants miss classes without notifying
investigators in advance, investigators will call to remind them about their classes and
encourage increased compliance.
Final assessment: Assessments completed at baseline will also be completed at endpoint
(26 weeks). The sub-set of participants at baseline who underwent MRI will also undergo
the MRI protocol at endpoint.
Data analysis: Behavioural data (cognitive assessments, mobility, and physical measures)
will be analyzed in SPSS. Primary and secondary outcome measures will be examined using
linear mixed models (LMMs), with time (baseline, endpoint), creatine supplementation, and
RT entered as fixed effects, including all two-way interactions and the creatine × RT ×
time interaction. The three-way interaction is the primary term of interest, testing
whether the combined effect of creatine and RT differs from baseline to endpoint. A
random intercept for participant will account for the correlation between each
participant's baseline and endpoint values. Models will adjust for relevant covariates,
including age, sex, and education. Structural MRI data will be processed and analysed
using FreeSurfer and FSL software packages
Analyses will be conducted according to the intention-to-treat principle, whereby all
randomized participants will be included in the final analysis regardless of adherence to
the intervention. Where outcome data are missing at random, multiple imputation methods
will be used if the assumptions for imputation are met. Sensitivity analyses will be
conducted to compare results from imputed and complete-case datasets. Reasons for missing
data will be reported, and descriptive analyses will be performed to compare participants
with complete and incomplete data.
Additional exploratory analyses will be conducted to examine potential moderators of
intervention effects, including sex, age, education level, baseline physical activity
levels, and baseline cognitive levels. Exploratory associations between changes in
neuroimaging outcomes, cognitive performance, and physical function measures will also be
explored.
Significance of research: This research is the first to address a critical gap in the
literature by examining the effects of creatine and resistance training alone and in
conjunction on various measures of physical function, cognitive function, and brain
health in older adults with mild cognitive impairment. In the context of an aging
population and given the overall safety and accessibility of creatine and resistance
training, the findings from our study may inform biomarker-driven, non-pharmacological
strategies and interventions to offset or defer further cognitive decline in older adults
with mild cognitive impairment.