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Trial registered on ANZCTR


Registration number
ACTRN12611000058976
Ethics application status
Not yet submitted
Date submitted
10/01/2011
Date registered
17/01/2011
Date last updated
17/01/2011
Type of registration
Prospectively registered

Titles & IDs
Public title
The genomics of taste receptors in the prevention of obesity
Scientific title
The genomics of taste receptors in the prevention of obesity amongst healthy human subjects via the evaluation of genetic (i.e., allelic variation and taste receptor gene expression) factors which are associated with taste sensitivity
Secondary ID [1] 253372 0
Nil
Universal Trial Number (UTN)
U1111-1118-9421
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 260911 0
Condition category
Condition code
Diet and Nutrition 259070 259070 0 0
Obesity

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
During this study participants will be involved in an exploratory discovery study, during which their dietary intake, weight status and taste sensitivity will be evaluated and compared with 1) allelic variation in taste receptor genes and 2) relative expression of taste receptor genes upon the tongue. A total of five testing sessions will be required for this study, including four x 60 minute taste tests, and one 90 minute session during which tongue tissue will be collected, taste papillae counted, and the questionnaires (food frequency questionnaire and implict attitudes test) will be completed. Taste testing will be done to determine detection thresholds for each tastant, as well as difference thresholds for each tastant. The detection threshold is the lowest concentration of a tastant required for it to be detected within the mouth, wheras the difference threshold is the concentration of a tastant required for it to be perceived as different from an identical tastant, at a different concentration. Testing will take place over a one month period, and all testing will be seperated by at least 24 hours.
Intervention code [1] 257811 0
Early detection / Screening
Comparator / control treatment
all participants will take part in this study, there will be no control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 259906 0
The primary outcome will be taste sensitivity, as measured by detection and difference thresholds for sweet, fatty acid, salty, sour, umami and bitter tastes. Detection thresholds are considered the lowest amount of a tastant required for it to be detected, whereas difference thresholds are the concentration of tastant required for it be tasted as different from another sample at suprathreshold (above detection threshold) concentrations.
Timepoint [1] 259906 0
Taste thresholds, both detection and difference thresholds for these tastants will be measured in duplicate. Detection and difference thresholds will be measured on seperated occasions, seperated by 24 hours.
Secondary outcome [1] 268795 0
Dietary intake, as assessed by a validated food frequency questionnaire (National Health and Nutritional Examination Survey (NHANES)), will be collected.
Timepoint [1] 268795 0
The food frequency questionnaire will be completed within one month of taste testing.
Secondary outcome [2] 268796 0
Allelic variation in taste receptor genes will be measured. This will be done following the collection of blood (30 mls) from each participant. DNA from whole blood will be amplified following Polymerase Chain Reaction (PCR) and combined with labelled taste receptor primers (also commercially available), which will be used to evaluate variation (Single Nucleotide Polymorphisms (SNPs)) in taste receptor genes.
Timepoint [2] 268796 0
Blood will be collected from all participants within one month of taste testing.
Secondary outcome [3] 268797 0
Weight, height and waist circumference will be collected. Weight will be collected in Kg using dedicated scales, height in cm using a wall mounted stadiometre and waist circumference using a dedicated measuring tape, which will be passed around the abdomen at belly-button height.
Timepoint [3] 268797 0
Weight, height and waist circumference will be collected in a single testing session, within one month of taste testing.
Secondary outcome [4] 268798 0
The number of taste papillae present on the tongue will be counted. For this, a 6 mm piece of filter paper, impregnated with blue food dye, will be placed on the anterior tongue, and used to stain a 6 mm area. Following staining, a picture of the tongue will be captured on a digital camera, blown up, and the papillae within the blue stained area will be counted.
Timepoint [4] 268798 0
Tongue papillae will be counted within one month of taste testing.
Secondary outcome [5] 268799 0
An Implicit Associations Test (IAT) will be used to capture associations and reactions to food images. This is a validated, time-reaction task used to evaluate subconcious reactions and associations to specific stimuli, in this case, foods.
Timepoint [5] 268799 0
The IAT will be administered within one month of taste testing.

Eligibility
Key inclusion criteria
For these studies, we are specifically seeking individuals who are:

- 18 years or older
- Living in metropolitan Sydney
- Proficient in both written and spoken English
- Able to attend testing sessions between the hours of 9:00 am - 5:00pm Monday to Friday
Minimum age
18 Years
Maximum age
55 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
For these studies we are specifically excluding individuals based upon the following criteria:

- Adults with known medical conditions known to affect weight (hyperthyroidism, Cushing syndrome etc)
- Individuals who are currently on, or have been on a diet, or specific dietary routine within the past 3 months
- Individuals who have experienced fluctuations in their weight by > 3 kg in the past 3 months
- Individuals who do not have adequate taste function
- Individuals who are restrained eaters (as defined by a score of > 12 on factor one of the eating attitudes test
- Individuals who are allergic to, or do not wish to consume dairy products
- Individuals over the age of 55 years
-Smokers

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
NA
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
NA
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Not yet recruiting
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] 258291 0
Government body
Name [1] 258291 0
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Address [1] 258291 0
CSIRO Food and Nutritional Sciences
Riverside Corporate Park
11 Julius Avenue
North Ryde
2113 NSW
Country [1] 258291 0
Australia
Primary sponsor type
Individual
Name
Dr Conor Delahunty
Address
CSIRO Food and Nutritional Sciences
Riverside Corporate Park
11 Julius Avenue
North Ryde
2113 NSW
Country
Australia
Secondary sponsor category [1] 257455 0
None
Name [1] 257455 0
Address [1] 257455 0
Country [1] 257455 0

Ethics approval
Ethics application status
Not yet submitted
Ethics committee name [1] 260277 0
CSIRO Food and Nutritional Sciences Human Research Ethics Commitee
Ethics committee address [1] 260277 0
CSIRO Food and Nutritional Sciences
Kintore Street
Adelaide, 5000
Adelaide
South Australia
Ethics committee country [1] 260277 0
Australia
Date submitted for ethics approval [1] 260277 0
30/01/2011
Approval date [1] 260277 0
Ethics approval number [1] 260277 0

Summary
Brief summary
Each year CSIRO Food and Nutritional Sciences perform a number of research projects involving human participants. The present study will be investigating genetic differences in taste perception and how they are associated with genetic factors, susceptibility to chronic disease and dietary intake.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 32067 0
Address 32067 0
Country 32067 0
Phone 32067 0
Fax 32067 0
Email 32067 0
Contact person for public queries
Name 15314 0
Ms Jessica Stewart
Address 15314 0
CSIRO Food and Nutritional Sciences
Riverside Corporate park
11 Julius Avenue
North Ryde
2113, NSW
Country 15314 0
Australia
Phone 15314 0
+ 61 29490 8363
Fax 15314 0
Email 15314 0
jessica.stewart@csiro.au
Contact person for scientific queries
Name 6242 0
Ms Jessica Stewart
Address 6242 0
CSIRO Food and Nutritional Sciences
Riverside Corporate park
11 Julius Avenue
North Ryde
2113, NSW
Country 6242 0
Australia
Phone 6242 0
+61 2 9490 8363
Fax 6242 0
Email 6242 0
jessica.stewart@csiro.au

No information has been provided regarding IPD availability
Summary results
No Results