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Trial registered on ANZCTR


Registration number
ACTRN12612000203853
Ethics application status
Approved
Date submitted
16/02/2012
Date registered
17/02/2012
Date last updated
14/10/2016
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effects of protein load on gut motility, gut hormone release, and sensations of appetite.
Scientific title
Effects of protein load on antropyloroduodenal motility, gut hormone release, and sensations of appetite in obese males.
Secondary ID [1] 279941 0
nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 285861 0
Condition category
Condition code
Diet and Nutrition 286043 286043 0 0
Obesity
Oral and Gastrointestinal 286044 286044 0 0
Normal oral and gastrointestinal development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A single 60 minute intraduodenal infusion at 4mL/min of
a) 0 kcal/min (saline control)
b) 1.5 kcal/min (Whey Protein Hydrolysate)
c) 3 kcal/min (Whey Protein Hydrolysate)
in 16 obese subjects

A single 60 minute intraduodenal infusion at 4mL/min of
a) 3 kcal/min (Whey Protein Hydrolysate)
in 16 lean subjects

Appetite sensation questionnaires in the form of a Visual Analogue Scale (VAS), blood samples.

A buffet meal will be provided at the end of the 60 minute infusion from which the volunteer has 30 minutes to eat until comfortably full. The buffet meal consists of 300ml orange juice, 600ml water, 375ml iced coffee, 4 slices white bread, 4 slices brown bread, 100g deli leg ham, 100g virginian chicken, 4 slices cheese, 100g tomato, 100g cucumber, 100g lettuce, 2 portions mayonnaise, 2 portions margarine, 1 medium apple, 1 medium banana, 200g chocolate custard, 150g fruit salad, 200g strawberry yoghurt, and a 14g milky way bar.

Each obese volunteer will receive one of each infusion solution over three study days. Each study visit will be seperated by no less than 3 days.

Each lean volunteer will receive the 3kcal/min infusion, requiring only 1 study visit.

Each study visit will last approximately 3-6 hours.
Intervention code [1] 284273 0
Treatment: Other
Comparator / control treatment
Both lean and obese volunteers will be deemed as controls for this study.

Obese volunteers will act as their own control via administration of a single 0kcal/min intraduodenal infusion of saline solution, delivered at a rate of 4mL/min for 60 minutes, to enable comparison to nutrient containing infusions in obese volunteers.

Age-matched lean volunteers will act as a control via administration of a single 3kcal/min intraduodenal infusion of Whey Protein Hydrolysate, delivered at a rate of 4mL/min for 60 minutes, for direct comparison between response in lean and obese volunteers to the 3kcal/min infusion.
Control group
Placebo

Outcomes
Primary outcome [1] 286523 0
Antropyloroduodenal motility (antropyloroduodenal pressures; number of antral, duodenal and isolated pyloric pressure waves; basal pyloric pressure) assessed by Manometry.
Timepoint [1] 286523 0
At t= -15 until 0, a baseline of the antropyloroduodenal (APD) motility is recorded.

Infusion starts at t=0 until t=60 minutes. APD motility is assessed continuously for the duration of the infusion (t=0-60 minutes).

Subject is extubated at t=60 minutes.
Primary outcome [2] 286524 0
Gut hormone concentrations: cholecyctokinin (CKK), glucagon-like peptide-1 (GLP-1), peptide YY (PYY), gastric inhibitory polypeptide (GIP), insulin.

Gut hormone concentrations will be assessed by Enzyme-Linked Immunosorbent Assay (ELISA)/radioimmunoassay (RIA) from the blood samples taken.
Timepoint [2] 286524 0
Intubation occurs on subject arrival.

At t= -15 the subject is cannulated and a baseline blood sample taken. Baseline APD motility is recorded between t= -15 and t=0.

Infusion starts at t=0 until t=60 minutes.

Extubation and buffet meal presented at t=60. Subject allowed to consume buffet meal for 30 minutes until comfortably full (until t=90).

Blood samples are taken at t= -15, 0, 15, 30, 45, 60, & 90 minutes.
Primary outcome [3] 286525 0
Macronutrient and total energy intake at the buffet meal will be analysed using the Foodworks software program.
Timepoint [3] 286525 0
Buffet meal will be presented at the end of the infusion and after extubation (t=60). The subject will be allowed to freely consume food for 30 minutes until comfortably full (until t=90).
Secondary outcome [1] 296084 0
Appetite sensations using a Visual Analogue Scale (VAS) (nausea, bloating, hunger, fullness, desire to eat, amount of food desired to eat).
Timepoint [1] 296084 0
Intubation occurs on subject arrival.

At t= -15 until t=0, a baseline of APD motility is recorded.

Infusion starts at t=0 until t=60 minutes.

Extubation and buffet meal presented at t=60. Subject allowed to consume buffet meal for 30 minutes until comfortably full (until t=90).

VAS questionnaires are given at t= -15, 0, 15, 30, 45, 60, & 90 minutes.

Eligibility
Key inclusion criteria
Obese with a Body Mass Index (BMI) of 30-35 kg/m2 and lean with a BMI of 18-25 kg/m2.

Weight stable (<5% fluctuation in body weight in previous 3 months).
Minimum age
18 Years
Maximum age
60 Years
Gender
Males
Can healthy volunteers participate?
No
Key exclusion criteria
Significant gastrointestinal symptoms, disease, or surgery

Use of prescribed or non-prescribed medications (including vitamins and herbal supplements) which may effect energy metabolism, gastrointestinal function, body weight, or appetite (eg. domperidone and cisapride, anticholinergic drugs (eg. atropine), metoclopramide, erythromycin, hyoscine, orlistat, green tea extracts, astragalus, St. johns wort etc.)

Lactose intolerant or other food allergies; intolerance or allergy to paracetomol

Current gallbladder or pancreatic disease; diabetes mellitus; epilepsy; cardiovasculr or respiratory diseases; any other illnesses as assessed by the investigator (including chronic illnesses not explicitly listed above)

Individuals with low ferritin levels or who have donated blood in the 12 weeks prior to taking part in the study

High performance athletes

Current intake of >2 standard drinks on >5 days per week

Current smokers of cigarettes/cigars/marijuana

Current intake of any illicit substance

Restrained eaters (score >12 on the three factor eating questionnaire)

Experience claustrophobia in confined spaces

Unable to tolerate nasogastrointestinal tube, or to comprehend study protocol

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)
Volunteers are asked to visit the clinic for a 30 minute screening visit. A screening questionnaire and three factor eating questionnaire are answered by the volunteer, and a blood sample taken for determination of ferritin levels. Eligibility is determined based on the inclusion/exclusion criteria. A signed informed consent form is obtained and study dates are established. Eligible volunteers are assigned a subject number and randomised into a treatment for each study visit (obese volunteers only) using a randomisation table created on an excel spreadsheet. Randomisation involves contacting the holder of the randomisation table (study assistant) to inform them of the subjects details and study dates. The unblinded study assistant is therefore responsible for allocating a random treatment to the subject and preparing the solution for infusion on each study day.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The randomisation table was created using Microsoft Office Excel.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Age-matched lean volunteers receive the 3 kcal/min infusion only to enable direct comparison of effects on primary and secondary outcomes between lean and obese.
Phase
Not Applicable
Type of endpoint(s)
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)
SA
Recruitment postcode(s) [1] 5002 0
5000
Recruitment postcode(s) [2] 5003 0
5043
Recruitment postcode(s) [3] 5004 0
5061
Recruitment postcode(s) [4] 5005 0
5038
Recruitment postcode(s) [5] 5006 0
5037
Recruitment postcode(s) [6] 5007 0
5045
Recruitment postcode(s) [7] 5008 0
5008
Recruitment postcode(s) [8] 5009 0
5006

Funding & Sponsors
Funding source category [1] 284716 0
Government body
Name [1] 284716 0
National Health and Medical Research Council Grant 627118
Address [1] 284716 0
Level 1 16 Marcus Clarke Street
Canberra ACT 2601
Country [1] 284716 0
Australia
Primary sponsor type
Individual
Name
Dr Natalie Luscombe-Marsh
Address
Level 6 Eleanor Harrald Building,
Frome Road,
Adelaide, SA 5000
Country
Australia
Secondary sponsor category [1] 283617 0
University
Name [1] 283617 0
University of Adelaide
Address [1] 283617 0
North Terrace
Adelaide, SA 5005
Country [1] 283617 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 286721 0
Royal Adelaide Hospital Research Ethics Committee
Ethics committee address [1] 286721 0
Level 3, Hanson Institute, North Terrace
Adelaide, South Australia, 5000
Ethics committee country [1] 286721 0
Australia
Date submitted for ethics approval [1] 286721 0
Approval date [1] 286721 0
20/12/2011
Ethics approval number [1] 286721 0
081012g

Summary
Brief summary
This study has been designed to investigate how the load of Whey Protein Hydolysate effects gut motility, gut hormones, and appetite sensations in obese individuals. Further, how response to a specific load of Whey Protein Hydolysate differs between obese and age-matched lean individuals will be investigated.

There is evidence that protein more potently suppresses appetite and energy intake than carbohydrate and fat, however, the mechanisms behind this are not clear, and many studies show variable results due to differences in methodology.

Our team has developed an intraduodenal infusion protocol appropriate to characterise the effects of varying protein loads in lean individuals on antropyloroduodenal motility, hormone release, and energy intake. Evidence suggests that normal hormone release and motility responses are perturbed in obese individuals.

Thus, this study aims to characterise the effects of protein loads on gut motility, gut hormones, appetite sensations, and subsequent energy intake in obese individuals. We hypothesise that protein will modulate these parameters in a load-dependent manner, however, obese subjects will be less sensitive to loads of protein infused into the duodenum, compared to a healthy lean population.

The results of this study may aid food and pharmaceutical industries in identifying appropriate responses to aid body weight management.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 33777 0
Dr Dr Natalie Luscombe-Marsh
Address 33777 0
Level 6, Eleanor Harrald Building, Frome Road, Adelaide, SA 5000
Country 33777 0
Australia
Phone 33777 0
+61 8 8222 5038
Fax 33777 0
Email 33777 0
natalie.luscombe@adelaide.edu.au
Contact person for public queries
Name 17024 0
Dr Dr Natalie Luscombe-Marsh
Address 17024 0
Level 6, Eleanor Harrald Building,
Frome Road,
Adelaide, SA 5000
Country 17024 0
Australia
Phone 17024 0
+61 8 8222 5038
Fax 17024 0
Email 17024 0
natalie.luscombe@adelaide.edu.au
Contact person for scientific queries
Name 7952 0
Dr Dr Natalie Luscombe-Marsh
Address 7952 0
Level 6, Eleanor Harrald Building,
Frome Road,
Adelaide, SA 5000
Country 7952 0
Australia
Phone 7952 0
+61 8 8222 5038
Fax 7952 0
Email 7952 0
natalie.luscombe@adelaide.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