A double-blind, cross-over, placebo-controlled, proof-of-concept study using oral peptide YY3-36 solution to investigate the mechanistic role of lingual PYY in regulating appetite, energy intake and food preference in people with overweight/obesity. The aim of this study is to investigate the mechanistic role of lingual PYY in regulating appetite, energy intake and food preference in people with overweight/obesity.
In order to address the study objective two independent investigations in two separate groups of participants will need to be undertaken, to avoid cross-contamination of the results. 1. Cohort/Investigation 1: A randomised within-subject double-blind cross-over placebo-controlled study to investigate the role of lingual PYY in regulating fasted and post-meal appetite following a fixed energy intake meal. 2. Cohort/Investigation 2: A randomised within-subject double-blind cross-over placebo-controlled study to investigate the role of lingual PYY in regulating ad libitum energy intake and food preference. People with overweight or obesity (BMI 25.0-39.9 kg/m2), identified via the University College London Hospitals (UCLH) Bariatric Centre for Weight Management and Metabolic Surgery and through advertising via University College London (UCL) and ULCH, will be invited to take part. Potential participants will initially attend a screening visit, where informed, written consent will first be taken. During the screening visit, medical, drug and dietary histories will be taken and participant eligibility will be confirmed. Participants will attend on two separate occasions at least 7 days apart for both cohort/investigation 1 and cohort/investigation 2. 20 participants per cohort/investigation will be randomised (in a 1:1 manner), stratified by sex, to receive either oral PYY3-36 solution or matched placebo at their first study visit. Participants will be recruited onto study/investigation 1 first and once this is complete, new subjects will be enrolled onto study/investigation 2. Cohort/Intervention 1: The day prior to each visit participants will complete a 24 hour food diary and appetite scores at home. Participants will fast overnight (12 hours) and consume only water until reaching the clinical facility the following morning. Participants will need to refrain from exercise for 2 days prior to the study visits and from drinking alcohol. On arrival, medical history will be re-reviewed, sociodemographic information collected and a pregnancy test for women of childbearing potential will be performed. Body weight and composition will be measured. Baseline assessments of fasted subjective appetite assessed using validated visual analogue scales (VAS), saliva PYY levels (via saliva sample) and circulating gut hormones (via blood sample) will be taken. A single dose of lingual PYY (GT-001) or placebo will be administered. Appetite scores and a paired blood and saliva sample will be collected 10-15 minutes later. 30 minutes after study drug application, participants will then be asked to consume a standardised fixed meal over 15 minutes using established protocol and appetite scores (VAS) and saliva and blood samples will be taken for 180 minutes post-meal at regular intervals. Participants will be asked to complete 24-hour food diary and appetite scores 6, 12 and 24 hours after the study visit. Cohort/Intervention 2: The day prior to each study visit participants will complete a 24-hour food diary and appetite scores at home. Participants will fast overnight (12 hours) and consume only water until reaching the clinical facility the following morning. Participants will need to refrain from exercise for 2 days prior to the study visits and from drinking alcohol. On arrival, medical history will be re-reviewed, sociodemographic information collected and a pregnancy test for women of childbearing potential will be performed. Body weight and composition will be measured. Baseline assessments of fasted subjective appetite assessed using validated VAS, saliva PYY levels (via saliva sample) and circulating gut hormones (via blood sample) will be taken. A single dose of lingual PYY (GT-001) or placebo will be administered. Appetite scores and a paired blood and saliva sample will be collected 10-15 minutes later. 30 minutes after study drug application, participants will be offered an extensive free-choice buffet lunch and asked to eat until full. Ad libitum energy intake and food preferences will be assessed. Participants will be asked to rank likeness of the items of the buffet. Appetite scores (VAS) and paired blood and saliva sample will be taken again 60 minutes from the onset of the meal. Participants will be asked to complete 24-hour food diary and appetite scores 24 hours after the study visit. After a 7-day washout period participants in each cohort/intervention will be crossed-over and the same visit will be repeated. Both the participants and researchers will be blinded to the study condition.
Study Type
OBSERVATIONAL
Enrollment
40
oral PYY3-36 solution
oral placebo solution
appetite scores
area-under-the curve for appetite scores. Not indicative of either bad or worse outcome, just subjective indication.
Time frame: up to 6 hours
energy intake expressed as Kcal of eaten food
ad libitum energy intake
Time frame: up to 6 hours
PYY levels
Area-under-the-curve for saliva PYY levels
Time frame: up to 6 hours
gut hormones levels
Area-under-the-curve for gut hormones levels
Time frame: up to 6 hours
24-h energy intake
Time frame: 24 hours after study visit
24h appetite
Subjective appetite scores for 24 hours following a fixed meal using VAS - a 1 to 10 scale will be used where the higher the score the higher the level of feeling of the item for the subject. No better or worse meaning applied a priory.
Time frame: 24 hours after study visit
macronutrient selection
Macronutrient content of consumed food during ad libitum meal
Time frame: up to 1 hour
food preference using labelled magnitude scales (LMS)
labelled magnitude scales (LMS) for components of the ad libitum meal
Time frame: through study completion, an average of 6 hours
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food preference questionnaire (FPQ)
The food preference questionnaire requires participants to rate their liking of 62 individual foods on a 5-point Likert scale, ranging from "not at all" to "a lot". A higher score indicative of greater liking of a food.
Time frame: once, at beginning of study visit