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Trial registered on ANZCTR


Registration number
ACTRN12612001105831
Ethics application status
Approved
Date submitted
12/10/2012
Date registered
16/10/2012
Date last updated
16/10/2012
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effect of glucose on cognitive function in healthy older adults
Scientific title
Glucose facilitation of cognitive function: A placebo-controlled, double-blind, randomized, crossover trial in healthy older adults aged over 65
Secondary ID [1] 281391 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cognitive Function 287627 0
Condition category
Condition code
Mental Health 287954 287954 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
This is a placebo-controlled, double-blind, randomized, crossover trial. Conditions will follow a 2 (placebo/glucose) X 2 (+/- secondary task) design.

Participants will be required to come for 5 visits. The first visit is a practice day where participants complete screening questionnaires and familiarise themselves with the study procedures and tests. The following 4 days are scheduled at least 48 hours apart and participants are randomised to receive one of two treatment drinks (25g glucose/placebo) and +/- the secondary tracking task.

Participants will be given a glucose drink on two testing days and a placebo drink on two testing days to be consumed orally. The drinks contain 20 ml of orange cordial in 150 ml water containing either 25g of glucose or 30 mg saccharine. These drinks have been used in numerous previous experiments into the effects of glucose on cognition. The two drinks are sensorily indistinguishable.

If they are in the secondary tracking task condition, they complete the tracking task on the computer while listening to the words. Following the word presentation, there is a word recognition task where participants are presented with the 20 original words mixed with 20 new words. Participants indicate whether or not the word was in the original list by clicking ‘yes’ or ‘no’. If they indicate yes, they are prompted to indicate whether they (1) remembered it was in the original list, (2) know it was in the original list, or (3) guessed it was in the original list.

Drinks will be consumed within 5 minutes, thereafter followed by secondary tracking task and memory encoding.
Intervention code [1] 285867 0
Treatment: Other
Comparator / control treatment
Matching sensorily indistinguishable placebo (saccharine)
Control group
Placebo

Outcomes
Primary outcome [1] 288169 0
Word recognition accuracy and reaction time

During memory encoding, participants will be orally presented with words via headphones connected to a computer screen. Eight of the words will be included as buffers, four at the beginning of the list and four at the end. Participants in the secondary tracking task condition will additionally complete the tracking task while listening to the words. This consists of participants following a moving target using the computer mouse. Following a short delay, there is a word recognition task where participants are presented with some of the original words mixed with some new words, one at a time on the computer screen. Participants indicate whether or not the word was in the original list by clicking 'yes' or 'no' with the mouse. If the participant responded 'yes', they are prompted to indicate their level of confidence of their answer. They click 'remember' to indicate conscious recollection of an item's appearance, 'know' when the item feels familiar but cannot recall its actual occurrence, or 'guess' if they are uncertain whether an item appeared. Standard instructions for this word recognition paradigm will be utilised.
Timepoint [1] 288169 0
30 mins post dose
Secondary outcome [1] 299540 0
ERP waveforms

In this study electroencephalagram (EEG) will be recorded from a 64 channel electrode cap using the Neuroscan system during the encoding and response stages of the recognition memory task. Electroculogram (EOG) will be recorded using tin electrodes above (E1) and below (E3) the left eye, above (E2) and below (E4) the right eye, from the outer canthi of the left (E5) and right (E6) eyes. Prior to performing the memory task eye movement data will be recorded from each subject to enable artifact to be removed from the signal during analysis. Event related potential (ERP) responses will be time-locked to word presentation during the encoding and response stages. ERP components recorded during the response stage of this task for previously unstudied items will be compared to those which participants indicate a 'remember' or 'know' response. Effects of glucose facilitation and effort will be assessed by comparing the averaged ERP components for the gluocose/placebo and tracking/non tracking conditions respectively.
Timepoint [1] 299540 0
30 mins post dose

Eligibility
Key inclusion criteria
1. Healthy non-smoking males and females aged over 65
2. No history of anxiety, depression, psychiatric disorders (confirmed using DASS) or epilepsy
3. No history of / do not currently suffer from heart disease or high blood pressure or diabetes
4. Not taking any medication, herbal extracts, vitamin supplements or illicit drugs which might reasonably be expected to interfere with blood glucose levels, for 4 weeks prior to (and duration of) study
5. Not taking any form of medication within 5 days of admission (except for prophylactic antibiotics, or other routine medications to treat benign conditions, such as antibiotics to treat acne) and agree not to take any medication throughout the study
6. No health conditions that would affect food metabolism including the following: food allergies, kidney disease, liver disease and/or gastrointestinal diseases (e.g. Irritable bowel syndrome, coeliac disease, peptic ulcers)
7. Are willing and able to participate in all scheduled visits, treatment plan, dietary restrictions, tests and other trial procedures according to the protocol. Also comfortable with computers.
8. Are willing to provide small finger prick blood samples and blood samples throughout the testing phases
9. Absence of cognitive decline and a score > 24 on the Mini Mental State Examination (MMSE)
10. Understand the rating scales and computer tests (as judged by the study coordinator)
13. Provide a personally signed and dated informed consent indicating that the participant has been informed of all pertinent aspects of the trial.
14. Have a fasting blood glucose <6.1mmol/l
Minimum age
65 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Smoker
2. Diagnosis of Type 1 or Type 2 diabetes
3. History of hypersensitivity to glucose
4. History of anxiety, depression, psychiatric disorders or epilepsy
5. History of / currently suffers from heart disease or high blood pressure or diabetes
6. Evidence or history of any clinically significant (in the judgment of the investigator) renal, endocrine, pulmonary, gastrointestinal, cardiovascular, psychiatric, neurological, within the last 5 years
7. Use of any over-the-counter herbal extracts, vitamin supplements and/or other dietary supplements which might influence glucose absorption or metabolism for four weeks prior to the practice day
8. Taking any illicit drugs
9. Health conditions that would affect food metabolism including the following: food allergies, kidney disease, liver disease and/or gastrointestinal diseases (e.g. have Irritable bowel syndrome, peptic ulcers)
10. Are not willing to provide small finger prick blood samples throughout the testing phases
11. Current participation in any other trials involving investigational or marketed products within 30 days prior to the practice day.
12. History of head injury/stroke
13. Any clinically relevant abnormalities in a volunteer’s medical history, physical examination, or results of laboratory tests.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants will respond to advertisements and pass a telephone screening interview before coming in for their screening and enrollment session. Participants will be allocated the next available sequential identification number which will correspond to a treatment number.

Both treatments are identical in appearance. Treatments will be in cups with lids with the participant identification number and treatment day clearly labelled by a disinterested third party. The trial products must be stored in accordance with the manufacturer’s instructions. Until dispensed to the participants, the trial products will be stored in a securely locked area, only accessible to authorized personnel.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomization of participants to treatment groups will be determined by random allocation. All 24 participants will be assigned a treatment and secondary task order using a Latin square. Eligible, recruited participants will be assigned a participant number. The randomisation order that has been placed next to the participant’s number will be the allocated treatment order for that individual.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Factorial
Other design features
Placebo-controlled, double-blind, randomized, crossover trial
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 286141 0
Government body
Name [1] 286141 0
Australian Research Council
Address [1] 286141 0
Level 2, 11 Lancaster Place
Majura Park ACT 2609
Country [1] 286141 0
Australia
Primary sponsor type
University
Name
Swinburne University of Technology
Address
Brain Sciences Institute, 400 Burwood Road, Hawthorn VIC 3122
Country
Australia
Secondary sponsor category [1] 284963 0
None
Name [1] 284963 0
Address [1] 284963 0
Country [1] 284963 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 288195 0
Swinburne University Human research Ethics Committee
Ethics committee address [1] 288195 0
PO Box 218, Hawthorn VIC 3122
Ethics committee country [1] 288195 0
Australia
Date submitted for ethics approval [1] 288195 0
Approval date [1] 288195 0
Ethics approval number [1] 288195 0
2010/055

Summary
Brief summary
This is a placebo-controlled, double-blind, randomized, crossover trial. Conditions will follow a 2 (placebo/glucose) X 2 (+/- secondary task) design.

Participants will be required to come for 5 visits. The first visit is a practice day where participants complete screening questionnaires and familiarise themselves with the study procedures and tests. The following 4 days are scheduled at least 48 hours apart and participants are randomised to receive one of two treatment drinks (25g glucose/placebo) and +/- the secondary tracking task.

They then undergo 8 blocks of testing. In each block they will be presented with 20 words in the auditory modality, via headphones connected to a computer. If they are in the secondary tracking task condition, they complete the tracking task on the computer while listening to the words. Following the word presentation, there is a word recognition task where participants are presented with the 20 original words mixed with 20 new words. Participants indicate whether or not the word was in the original list by clicking ‘yes’ or ‘no’. If they indicate yes, they are prompted to indicate whether they (1) remembered it was in the original list, (2) know it was in the original list, or (3) guessed it was in the original list. 64 channels of EEG will be recorded during whilst participants perform this recognition memory task. Levels of blood glucose, insulin and cortisol will be taken throughout the study days
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 34827 0
Address 34827 0
Country 34827 0
Phone 34827 0
Fax 34827 0
Email 34827 0
Contact person for public queries
Name 18074 0
Antionette Goh
Address 18074 0
Mail H24, PO Box 218, Swinburne University,
Hawthorn VIC 3122
Country 18074 0
Australia
Phone 18074 0
+613 9214 5094
Fax 18074 0
Email 18074 0
agoh@swin.edu.au
Contact person for scientific queries
Name 9002 0
Prof Andrew Scholey
Address 9002 0
Mail H24, PO Box 218, Swinburne University,
Hawthorn VIC 3122
Country 9002 0
Australia
Phone 9002 0
+613 9214 8932
Fax 9002 0
Email 9002 0
ascholey@swin.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary