Bariatric Surgery CandidateNCT05404061
The Poor Responders Study
A study testing Gut hormones in people with Bariatric Surgery Candidate and Obesity, Morbid, run by Imperial College London at 1 site in United Kingdom.
Trial summary
Obesity and type 2 diabetes are major causes of illness and premature death worldwide and their incidence is increasing rapidly. Bariatric surgery is considered as the "gold-standard" surgical treatment for both conditions. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Bariatric Surgery Candidate, Obesity, Morbid, Diabetes Mellitus, Type 2
- What is being tested?
- Gut hormones
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 220 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 1 Aug 2018to 1 Sep 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged 18 -70 years.
- Male or female.
- Previous bariatric surgery for obesity and/or diabetes (studies 1 and 2).
- ≥1 year interval after bariatric surgery (studies 1 and 2).
- Awaiting bariatric surgery at the Imperial Weight Centre (study 3)
- Able to give informed consent.
Who cannot join
- History of any medical, psychological or other condition, or use of any medications, including over-the-counter products, which, in the opinion of the investigators, would either interfere with the study or potentially cause harm to the volunteer.
- Without access at home to a telephone or other factor likely to interfere with ability to participate reliably in the study.
- Pregnancy or breastfeeding.
- Unable to maintain adequate contraception for the duration of the study and for one month afterwards.
- History of hypersensitivity to any of the components of the subcutaneous infusions.
- Donated blood during the preceding 3 months or intention to do so before the end of the study.
Show all 11Show fewer
- Any other co-morbidity that would compromise the validity of the study or the safety of the participant such as heart failure or clinically apparent cardiovascular disease.
- Anatomical or endocrinological pathology causing poor weight loss or weight regain
- Uncontrolled hypertension (systolic blood pressure of 160 mmHg or above and/or diastolic blood pressure of 100 mmHg or above)
- Participation in a research study within the last two months.
- Unable to speak English (this is relevant to answering the psychological questionnaires)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United Kingdom1 site, 1 recruiting
- Recruiting
Imperial College London
London, W120NN
Kleopatra Alexiadou, PhD, 02033138038 ext. 38038, k.alexiadou@imperial.ac.uk
About this study
Official title: Why do Some Patients Respond Better Than Others to Bariatric Surgery?
Obesity and type 2 diabetes are major causes of illness and premature death worldwide and their incidence is increasing rapidly. Bariatric surgery is considered as the "gold-standard" surgical treatment for both conditions.
However, not all patients do equally well after surgery and indeed the weight loss experienced by patients undergoing bariatric surgery can vary. As such when patients are seen after bariatric surgery in clinic they fall in one of the following two categories:
Read more
- Good responders: this is the majority of patients who lose the expected amount of weight based on the published studies.
- Poor responders: this is a small group of patients who either lose less than the expected amount of weight after bariatric surgery or lose the expected amounts of weight early after surgery but then regain a substantial proportion of the weight they have lost.
The so-called "poor responders" are exposed to all the risks of the operation and do not benefit from the weight loss as much as good responders.
This study would therefore like to investigate the physiological factors that distinguish poor from good responders before, and after bariatric surgery. The study team hypothesizes that compared to good responders, poor responders exhibit:
- a smaller degree of fullness sensation after a meal,
- a lower energy expenditure after a meal, and
- genetic changes (single nucleotide polymorphisms) that predispose the poor responder to development of obesity.
In addition, the study team hypothesizes that poor responders exhibit:
- lower gut hormone secretion after a meal and
- are less sensitive to the physiological action of gut hormones compared to good responders and that this difference in gut hormone secretion and response to gut hormones prior to bariatric surgery can be helpful to predict response to bariatric surgery.
- Being tested
- Gut hormones
- Medical subject headings
- Obesity, Morbid, Diabetes Mellitus, Type 2
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gut hormonesOther
Their first visit will act as an acclimatisation visit and participants will be infused subcutaneously with a triple gut hormone infusion (GLP-1, PYY and OXM). This will not only allow us to acclimatise the study volunteer to the study visits, but also allow us to test for subject tolerability of the gut hormones.
For the next two visits participants will be randomised in a single-blinded fashion to a subcutaneous infusion of either:
- 0.9% saline,
- GLP-1
| Study group | Role | What they receive |
|---|---|---|
| Gut hormone secretion study | No intervention | This will be a retrospective study of participants who have undergone bariatric surgery. On the day of the visit participants will undergo comprehensive physiological profiling which will include the following tests: * Body weight and bioelectrical impedance analysis * Mixed Meal Tolerance Test. This will be analysed for metabolites including gut hormones, insulin, glucose, bile acids and their sub-fractions, fibroblast-growth factors, lipids and immune profiles. * Resting Energy Expenditure and Diet Induced Thermogenesis assessed via Indirect Calorimetry * Metabolomic and Metagenomic Assessment |
| Gut hormone sensitivity study | Placebo comparator | This will be a single blinded study with participants attending three visits. Their first visit will act as an acclimatisation visit and participants will be infused subcutaneously with a triple gut hormone infusion (GLP-1, PYY and OXM). This will not only allow us to acclimatise the study volunteer to the study visits, but also allow us to test for subject tolerability of the gut hormones. Occasionally some volunteers are more sensitive to the gut hormone infusion and the doses needs to be titrated down. The doses used will be established doses of the gut hormones infused previously and which have been shown to be safe and tolerated, and to reduce appetite (In house data). Receives: Other: Gut hormones |
| Prospective assessment of gut hormone response pre and post-surgery | No intervention | This will be a prospective study assessing the gut hormone response pre and post bariatric surgery. On the day of the visit participants will undergo comprehensive physiological profiling which will include the following tests: * Body weight and bioelectrical impedance analysis * Mixed Meal Tolerance Test. This will be analysed for metabolites including gut hormones, insulin, glucose, bile acids and their sub-fractions, fibroblast-growth factors, lipids and immune profiles. * Resting Energy Expenditure and Diet Induced Thermogenesis assessed via Indirect Calorimetry * Metabolomic and Metagenomic Assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gut hormone secretion study: Peak plasma level of gut hormones after meal ingestion
A standardized mixed-meal tolerance test. Blood samples will be taken at intervals over four hours. These will be analysed for gut hormones.
Measured: During one study visit (Mixed Meal Test), at least 1 year post-surgery.
Gut hormone sensitivity study: Change in Food intake following gut hormone infusion compared to placebo.
Ad libitum meal test. A meal will be served to participants and they will be allowed 20 minutes to eat until they feel comfortably full. Food intake will be measured at the end of the meal.
Measured: During three study visits (gut hormone infusion visits), at least 1 year post-surgery.
Prospective assessment of gut hormone response pre and post-surgery: Change in Peak plasma level of gut hormones after meal ingestion.
A standardized mixed-meal tolerance test. Blood samples will be taken at intervals over four hours. These will be analysed for gut hormones.
Measured: During two study visits (Mixed Meal Test), one before and one 1 year after surgery.
Secondary outcomes (3)
Change in Resting Energy Expenditure
Resting energy expenditure assessment via indirect calorimetry.
Measured: Change between two visits: before and 1 year after bariatric surgery (Prospective assessment of gut hormone response pre and post-surgery).
Change in Diet Induced Thermogenesis
Diet induced thermogenesis assessment via indirect calorimetry.
Measured: Change between two visits: before and 1 year after bariatric surgery (Prospective assessment of gut hormone response pre and post-surgery).
Change in Genetic factors
Change in genetic factors assessed by collection of plasma DNA samples.
Measured: Change between two visits: Before and 1 year after bariatric surgery.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Jun 2022
- Study start1 Aug 2018
- Primary completion1 Sep 2027 (estimated)
- Study completion1 Sep 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Bariatric Surgery CandidateStudies of the same condition, open and under way.
- More trials run by Imperial College LondonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 220 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Imperial College London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Tricia M Tan, PhD, Principal investigator, Imperial College London
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05404061
- Sponsor's protocol ID
- 17/LO/1323
- Status last verified
- May 2025
- First submitted
- 8 Mar 2022
- Last updated
- 9 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Aasheim ET, Aylwin SJ, Radhakrishnan ST, Sood AS, Jovanovic A, Olbers T, le Roux CW. Assessment of obesity beyond body mass index to determine benefit of treatment. Clin Obes. 2011 Apr;1(2-3):77-84. doi: 10.1111/j.1758-8111.2011.00017.x. Epub 2011 Jul 5.
PubMed 25585572Batterham RL, Cowley MA, Small CJ, Herzog H, Cohen MA, Dakin CL, Wren AM, Brynes AE, Low MJ, Ghatei MA, Cone RD, Bloom SR. Gut hormone PYY(3-36) physiologically inhibits food intake. Nature. 2002 Aug 8;418(6898):650-4. doi: 10.1038/nature00887.
PubMed 12167864De Silva A, Salem V, Long CJ, Makwana A, Newbould RD, Rabiner EA, Ghatei MA, Bloom SR, Matthews PM, Beaver JD, Dhillo WS. The gut hormones PYY 3-36 and GLP-1 7-36 amide reduce food intake and modulate brain activity in appetite centers in humans. Cell Metab. 2011 Nov 2;14(5):700-6. doi: 10.1016/j.cmet.2011.09.010. Epub 2011 Oct 13.
PubMed 22000927Laferrere B, Swerdlow N, Bawa B, Arias S, Bose M, Olivan B, Teixeira J, McGinty J, Rother KI. Rise of oxyntomodulin in response to oral glucose after gastric bypass surgery in patients with type 2 diabetes. J Clin Endocrinol Metab. 2010 Aug;95(8):4072-6. doi: 10.1210/jc.2009-2767. Epub 2010 May 25.
PubMed 20501690Tan TM, Field BC, McCullough KA, Troke RC, Chambers ES, Salem V, Gonzalez Maffe J, Baynes KC, De Silva A, Viardot A, Alsafi A, Frost GS, Ghatei MA, Bloom SR. Coadministration of glucagon-like peptide-1 during glucagon infusion in humans results in increased energy expenditure and amelioration of hyperglycemia. Diabetes. 2013 Apr;62(4):1131-8. doi: 10.2337/db12-0797. Epub 2012 Dec 17.
PubMed 23248172
Study at a glance
From the registry record, last updated by the sponsor on 9 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Why do Some Patients Respond Better Than Others to Bariatric Surgery?
- ClinicalTrials.gov ID
- NCT05404061
- Acronym / sponsor ID
- 17/LO/1323
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 220 participants (estimated)
- Lead sponsor
- Imperial College LondonUniversity, hospital or other
- Study start
- 1 Aug 2018 (actual)
- Primary completion
- 1 Sep 2027 (estimated)
- Study completion
- 1 Sep 2027 (estimated)
- First posted
- 3 Jun 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Obesity and type 2 diabetes are major causes of illness and premature death worldwide and their incidence is increasing rapidly. Bariatric surgery is considered as the "gold-standard" surgical treatment for both conditions.
However, not all patients do equally well after surgery and indeed the weight loss experienced by patients undergoing bariatric surgery can vary. As such when patients are seen after bariatric surgery in clinic they fall in one of the following two categories:
- Good responders: this is the majority of patients who lose the expected amount of weight based on the published studies.
- Poor responders: this is a small group of patients who either lose less than the expected amount of weight after bariatric surgery or lose the expected amounts of weight early after surgery but then regain a substantial proportion of the weight they have lost.
The so-called "poor responders" are exposed to all the risks of the operation and do not benefit from the weight loss as much as good responders.
This study would therefore like to investigate the physiological factors that distinguish poor from good responders before, and after bariatric surgery. The study team hypothesizes that compared to good responders, poor responders exhibit:
- a smaller degree of fullness sensation after a meal,
- a lower energy expenditure after a meal, and
- genetic changes (single nucleotide polymorphisms) that predispose the poor responder to development of obesity.
In addition, the study team hypothesizes that poor responders exhibit:
- lower gut hormone secretion after a meal and
- are less sensitive to the physiological action of gut hormones compared to good responders and that this difference in gut hormone secretion and response to gut hormones prior to bariatric surgery can be helpful to predict response to bariatric surgery.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Gut hormone secretion study | No intervention | –This will be a retrospective study of participants who have undergone bariatric surgery. On the day of the visit participants will undergo comprehensive physiological profiling which will include the following tests: * Body weight and bioelectrical impedance analysis * Mixed Meal Tolerance Test. This will be analysed for metabolites including gut hormones, insulin, glucose, bile acids and their sub-fractions, fibroblast-growth factors, lipids and immune profiles. * Resting Energy Expenditure and Diet Induced Thermogenesis assessed via Indirect Calorimetry * Metabolomic and Metagenomic Assessment |
| Gut hormone sensitivity study | Placebo comparator | Other: Gut hormonesThis will be a single blinded study with participants attending three visits. Their first visit will act as an acclimatisation visit and participants will be infused subcutaneously with a triple gut hormone infusion (GLP-1, PYY and OXM). This will not only allow us to acclimatise the study volunteer to the study visits, but also allow us to test for subject tolerability of the gut hormones. Occasionally some volunteers are more sensitive to the gut hormone infusion and the doses needs to be titrated down. The doses used will be established doses of the gut hormones infused previously and which have been shown to be safe and tolerated, and to reduce appetite (In house data). |
| Prospective assessment of gut hormone response pre and post-surgery | No intervention | –This will be a prospective study assessing the gut hormone response pre and post bariatric surgery. On the day of the visit participants will undergo comprehensive physiological profiling which will include the following tests: * Body weight and bioelectrical impedance analysis * Mixed Meal Tolerance Test. This will be analysed for metabolites including gut hormones, insulin, glucose, bile acids and their sub-fractions, fibroblast-growth factors, lipids and immune profiles. * Resting Energy Expenditure and Diet Induced Thermogenesis assessed via Indirect Calorimetry * Metabolomic and Metagenomic Assessment |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Aged 18 -70 years.
- Male or female.
- Previous bariatric surgery for obesity and/or diabetes (studies 1 and 2).
- ≥1 year interval after bariatric surgery (studies 1 and 2).
- Awaiting bariatric surgery at the Imperial Weight Centre (study 3)
Key exclusion criteria (11 listed)
- History of any medical, psychological or other condition, or use of any medications, including over-the-counter products, which, in the opinion of the investigators, would either interfere with the study or potentially cause harm to the volunteer.
- Without access at home to a telephone or other factor likely to interfere with ability to participate reliably in the study.
- Pregnancy or breastfeeding.
- Unable to maintain adequate contraception for the duration of the study and for one month afterwards.
- History of hypersensitivity to any of the components of the subcutaneous infusions.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Gut hormonesTheir first visit will act as an acclimatisation visit and participants will be infused subcutaneously with a triple gut hormone infusion (GLP-1, PYY and OXM). This will not only allow us to acclimatise the study volunteer to the study visits, but also allow us to test for subject tolerability of the gut hormones. For the next two visits participants will be randomised in a single-blinded fashion to a subcutaneous infusion of either: 1. 0.9% saline, 2. GLP-1 | Other | Gut hormone sensitivity study |
Primary outcome
Gut hormone secretion study: Peak plasma level of gut hormones after meal ingestion
Time frame: During one study visit (Mixed Meal Test), at least 1 year post-surgery.
A standardized mixed-meal tolerance test. Blood samples will be taken at intervals over four hours. These will be analysed for gut hormones.
Gut hormone sensitivity study: Change in Food intake following gut hormone infusion compared to placebo.
Time frame: During three study visits (gut hormone infusion visits), at least 1 year post-surgery.
Ad libitum meal test. A meal will be served to participants and they will be allowed 20 minutes to eat until they feel comfortably full. Food intake will be measured at the end of the meal.
Prospective assessment of gut hormone response pre and post-surgery: Change in Peak plasma level of gut hormones after meal ingestion.
Time frame: During two study visits (Mixed Meal Test), one before and one 1 year after surgery.
A standardized mixed-meal tolerance test. Blood samples will be taken at intervals over four hours. These will be analysed for gut hormones.
3 secondary outcomes
Change in Resting Energy Expenditure
Time frame: Change between two visits: before and 1 year after bariatric surgery (Prospective assessment of gut hormone response pre and post-surgery).
Change in Diet Induced Thermogenesis
Time frame: Change between two visits: before and 1 year after bariatric surgery (Prospective assessment of gut hormone response pre and post-surgery).
Change in Genetic factors
Time frame: Change between two visits: Before and 1 year after bariatric surgery.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 May 2025.
- Background: PubMed 25585572Aasheim ET, Aylwin SJ, Radhakrishnan ST, Sood AS, Jovanovic A, Olbers T, le Roux CW. Assessment of obesity beyond body mass index to determine benefit of treatment. Clin Obes. 2011 Apr;1(2-3):77-84. doi: 10.1111/j.1758-8111.2011.00017.x. Epub 2011 Jul 5.
- Background: PubMed 12167864Batterham RL, Cowley MA, Small CJ, Herzog H, Cohen MA, Dakin CL, Wren AM, Brynes AE, Low MJ, Ghatei MA, Cone RD, Bloom SR. Gut hormone PYY(3-36) physiologically inhibits food intake. Nature. 2002 Aug 8;418(6898):650-4. doi: 10.1038/nature00887.
- Background: PubMed 22000927De Silva A, Salem V, Long CJ, Makwana A, Newbould RD, Rabiner EA, Ghatei MA, Bloom SR, Matthews PM, Beaver JD, Dhillo WS. The gut hormones PYY 3-36 and GLP-1 7-36 amide reduce food intake and modulate brain activity in appetite centers in humans. Cell Metab. 2011 Nov 2;14(5):700-6. doi: 10.1016/j.cmet.2011.09.010. Epub 2011 Oct 13.
- Background: PubMed 20501690Laferrere B, Swerdlow N, Bawa B, Arias S, Bose M, Olivan B, Teixeira J, McGinty J, Rother KI. Rise of oxyntomodulin in response to oral glucose after gastric bypass surgery in patients with type 2 diabetes. J Clin Endocrinol Metab. 2010 Aug;95(8):4072-6. doi: 10.1210/jc.2009-2767. Epub 2010 May 25.
- Background: PubMed 23248172Tan TM, Field BC, McCullough KA, Troke RC, Chambers ES, Salem V, Gonzalez Maffe J, Baynes KC, De Silva A, Viardot A, Alsafi A, Frost GS, Ghatei MA, Bloom SR. Coadministration of glucagon-like peptide-1 during glucagon infusion in humans results in increased energy expenditure and amelioration of hyperglycemia. Diabetes. 2013 Apr;62(4):1131-8. doi: 10.2337/db12-0797. Epub 2012 Dec 17.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Tricia M Tan, PhD principal investigator
Imperial College London
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Gut hormones in people with Bariatric Surgery Candidate and Obesity, Morbid, run by Imperial College London at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 9 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kleopatra Alexiadou, PhD (+442033138038 ext. 38038, k.alexiadou@imperial.ac.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gut hormone secretion study: Peak plasma level of gut hormones after meal ingestion (time frame: During one study visit (Mixed Meal Test), at least 1 year post-surgery.). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05404061, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 May 2025.