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Trial registered on ANZCTR


Registration number
ACTRN12609001074280
Ethics application status
Approved
Date submitted
30/11/2009
Date registered
15/12/2009
Date last updated
15/12/2009
Type of registration
Retrospectively registered

Titles & IDs
Public title
How do interactions between oral and small intestinal exposure to oleic acid influence gastrointestinal function in healthy lean and obese participants
Scientific title
Interactions between oral and small intestinal exposure to oleic acid: effects on antropyloroduodenal pressures, gut peptide and oleoylethanolamine (OEA) release, serum triglyceride concentrations, appetite and energy intake in healthy lean and obese participants.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 252319 0
Condition category
Condition code
Diet and Nutrition 252500 252500 0 0
Obesity
Oral and Gastrointestinal 252501 252501 0 0
Normal oral and gastrointestinal development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will undergo sensory testing to determine whether or not they are sensitive to the taste of the free fatty acid, oleic acid, in a milk-based drink. They will be asked to taste and rate solutions with and without oleic acid, those who correctly identify the solution containing oleic acid on three occasions will be classed as tasters, those who do not taste it, or rate it incorrectly more than once will be classified as non-tasters. Following categorization into either the “taster”, or “non-taster”, group, each participant will be studied on four occasions, separated by at least 7 days, to evaluate the effects of:
(i)oral exposure to a non-fat milk-based beverage with 1.8 mM oleic acid (C18:1) (10 ml samples at 3 minute intervals for 20 minutes)combined with a 90 minute intraduodenal infusion of C18:1 (participants will be intubated with an nasoduodenal catheter through which the infusion will be administered at a rate of 2 ml/min, 0.76 kcal/min)
(ii)oral exposure to a non-fat milk-based beverage without C18:1 combined with intraduodenal infusion of C18:1
(iii)oral exposure to a non-fat milk-based beverage with 1.8 mM C18:1 combined with intraduodenal infusion of control (0.9 % saline)
(iv)oral exposure to a non-fat milk-based beverage without C18:1 combined with intraduodenal infusion of control (0.9 % saline)
Intervention code [1] 255624 0
Lifestyle
Comparator / control treatment
oral exposure to a non-fat milk-based beverage without C18:1 combined with intraduodenal infusion of control (0.9 % saline).

Taster and non-taster groups will be studied to determine whether fat taste sensitivity is required for the effects of oleic acid on gut function and energy intake.
Control group
Active

Outcomes
Primary outcome [1] 253388 0
During the 90 minute intraduodenal infusion antropyloduodenal motility will be assessed via changes in the pressures within specific portion of the gastrointestinal tract (antrum, pylorus and duodenum) which will be captured by sensors on the catheter connected to a computer-based system, running commercially available hardware (Oakdale Flexisoft)
Timepoint [1] 253388 0
Continuous measurement from t = -15 - 90 minutes
Primary outcome [2] 253389 0
15 ml blood samples will be collected. Blood samples will be analysed for blood glucose, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), insulin, pancreatic polypeptide ((PP), a marker of neuronal activation), peptide PYY (PYY), oleoylethanolamine (OEA) and ghrelin, as well as serum triglyceride concentrations. Radioimmunoassays and mass spectroscopy will be utilised.
Timepoint [2] 253389 0
t = 0, 5, 10, 15, 20, 30, 45, 60, and 90 minutes.
Primary outcome [3] 253390 0
Energy intake will be assessed using a buffet-style meal. Participants will be presented with a meal in excess of what they would normally be expected to consume and invited to eat until comfortably full. Foods will be weighed before and after consumption.
Timepoint [3] 253390 0
t = 90 - 120 minutes.
Primary outcome [4] 253391 0
Appetite perceptions will be assessed using validated visual analogue scale questionnaires
Timepoint [4] 253391 0
t = -15, 0, 15, 20, 45, 60 75, and 90 minutes.
Primary outcome [5] 253392 0
Fatty acid taste sensitivity. Subjects will taste and evaluate 10 ml aliquots of a non-fat milk based beverage, with and without 1.8 mM oleic acid (C18:1). 1.8 mM was chosen as in a previous study approximately 50 % of subjects could detect C18:1 at, or below, this concentration. The test involves choosing an odd sample from a group of three samples based on taste (subjects wear nose-clips to ensure detection of differences is not due to smell). Each subject will receive a tray containing 3 sets of 3 * 10 ml samples randomly sorted and labelled with 3-digit blinding codes. Subjects will be instructed to move back and forward through the samples from one set and to identify the ?odd? sample.
Timepoint [5] 253392 0
Screening visit
Secondary outcome [1] 262472 0
Habitual energy and fat intakes will be assessed using a food frequence questionnaire.
Timepoint [1] 262472 0
Screening visit

Eligibility
Key inclusion criteria
Equal numbers of healthy male and female subjects, 15 of normal body weight for their height (body mass index (BMI): 19 - 25 kg/m2), and 15 obese (BMI 30 – 35 kg/m2), aged 18-55 years. Subjects will need to be unrestrained eaters, non-smokers, and for female subjects will be required to be taking an appropriate hormonal contraceptive.
Minimum age
18 Years
Maximum age
55 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
(1)significant gastrointestinal symptoms; disease or surgery
(2)current use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may affect energy metabolism, GI function, body weight or appetite (e.g. domperidone and cisapride, anticholinergic drugs (e.g. atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, Astragalus, St John's Wort etc.)
(3)diabetes mellitus
(4)epilepsy
(5)cardiovascular or respiratory disease
(6)any other significant illness as assessed by the investigator
(7)allergy to local anaesthetic
(8)intake of > 20 g alcohol on a daily basis
(9)smokers (cigarettes, cigars, marijuana)
(10)in female subjects, pregnancy or lactation. A pregnancy test will be performed in all female subjects, using a urine sample, prior to commencement of the study and subsequently prior to each study day
(11)restrained eaters, as determined by a score of >12 on the eating restraint questionnaire component of the eating questionnaire (35). However, while the degree of eating restraint will be assessed and recorded in the obese subjects, this will not be used as an exclusion criteria, as the majority of obese subjects are likely to have some degree of eating restraint.
(12)donation of blood in the 12 weeks prior to enrolment in the study. Subjects will also be instructed to abstain from donating blood for 12 weeks after study completion
(13)low iron levels
(14)consumption of a vegetarian diet

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Volunteers will be recruited from an existing pool of lean and obese volunteers available in the Department, by flyers placed around the Royal Adelaide Hospital and Universities, and also by advertisements placed in The ‘Advertiser’ and ‘The Messenger’. Participants will be randomised into the study, and the study will be conducted in a double-blind randomised fashion. Allocation will not be concealed.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation table generated by statistical software
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
10/01/2009
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
30
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
Recruitment postcode(s) [1] 2346 0
5000

Funding & Sponsors
Funding source category [1] 256107 0
University
Name [1] 256107 0
University of Adelaide
Country [1] 256107 0
Australia
Primary sponsor type
Individual
Name
Dr Tanya Little
Address
University of Adelaide Discipline of Medicine
Level 6, Eleanor Harrald Building
Royal Adelaide Hospital
North Terrace
Adelaide, South Australia, 5000
Country
Australia
Secondary sponsor category [1] 251452 0
Individual
Name [1] 251452 0
Assoc. Prof. Christine Feinle-Bisset
Address [1] 251452 0
University of Adelaide Discipline of Medicine
Level 6, Eleanor Harrald Building
Royal Adelaide Hospital
North Terrace
Adelaide, South Australia, 5000
Country [1] 251452 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 258192 0
Royal Adelaide Hospital Research Ethics Committee
Ethics committee address [1] 258192 0
(Ms Heather O'Dea, Executive Officer)
Level 3, Hanson Insitute
Royal Adelaide Hospital
North Terrace
Adelaide, South Australia, 5000
Ethics committee country [1] 258192 0
Australia
Date submitted for ethics approval [1] 258192 0
Approval date [1] 258192 0
13/11/2009
Ethics approval number [1] 258192 0
091109

Summary
Brief summary
To evaluate the hypotheses:
(i) that both oral and small intestinal exposure to oleic acid (C18:1) will modulate antropyloroduodenal pressures, gut peptide, OEA and serum triglyceride responses, and suppress energy intake
(ii) that combined oral and small intestinal exposure to oleic acid will interact to enhance the stimulation of antropyloroduodenal pressures, gut peptide, OEA and serum triglyceride responses, and suppression of energy intake, when compared with either oral or small intestinal infusion alone, and
(iii) that these effects will occur in “tasters”, but not “non-tasters”, of oleic acid.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 30563 0
Address 30563 0
Country 30563 0
Phone 30563 0
Fax 30563 0
Email 30563 0
Contact person for public queries
Name 13810 0
Dr Tanya Little
Address 13810 0
University of Adelaide, Discipline of Medicine
L6, Eleanor Harrald Building
Royal Adelaide Hospital
North Terrace
Adelaide, SA, 5000
Country 13810 0
Australia
Phone 13810 0
+61 8 8222 0724
Fax 13810 0
+61 8 8223 3870
Email 13810 0
[email protected]
Contact person for scientific queries
Name 4738 0
Dr Tanya Little
Address 4738 0
University of Adelaide, Discipline of Medicine
L6, Eleanor Harrald Building
Royal Adelaide Hospital
North Terrace
Adelaide, SA, 5000
Country 4738 0
Australia
Phone 4738 0
+61 8 8222 0724
Fax 4738 0
+61 8 8223 3870
Email 4738 0
[email protected]

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No Supporting Document Provided



Results publications and other study-related documents

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