Investigating gut hormones after gastric bypass surgery

Do Gut Hormones Mediate the Beneficial Effects of Roux-en-Y Bypass?

This study is testing how certain gut hormones change after gastric bypass surgery to see if they help with weight loss and managing blood sugar in people with obesity and type 2 diabetes.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 190 (estimated)
• Ages: 18 Years to 70 Years
• Sex: All
• Sponsor: Imperial College London (Academic / other)
• Locations: 1 site (London, Greater London)
• Trial ID: NCT01945840 on ClinicalTrials.gov

What this trial studies

This study aims to explore the role of gut hormones in the metabolic benefits observed after Roux-en-Y gastric bypass surgery. It will assess the chronic elevation of hormones such as GLP-1, oxyntomodulin, and PYY, and their impact on glycaemia, energy expenditure, food intake, and weight loss. Participants will undergo surgery, receive gut hormone infusions, and follow a very low-calorie diet to evaluate these effects. The study seeks to clarify the mechanisms behind the surgery's effectiveness in treating obesity and type 2 diabetes.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18-70 with impaired glucose regulation or type 2 diabetes who are eligible for bariatric surgery.

Not a fit: Patients with a history of medical or psychological conditions that could interfere with the study or those who are pregnant or breastfeeding may not benefit.

Why it matters

Potential benefit: If successful, this study could lead to improved treatment strategies for obesity and type 2 diabetes through better understanding of gut hormones.

How similar studies have performed: Other studies have shown promising results in understanding the role of gut hormones in metabolic changes post-surgery, indicating this approach has potential.

Eligibility criteria

Inclusion criteria

* Aged 18 - 70 years.
* Male or female.
* Eligible for bariatric surgery under the NHS.
* Diagnosed with impaired glucose regulation or type 2 diabetes, according to WHO 2011 criteria.
* Those with diabetes should be stable and well controlled with either diet or one oral hypoglycaemic agent.
* HbA1c ≤9.0% or 74.9 mmol/mol.

Exclusion criteria

* 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.
* Smokers.
* 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.
* Insulin treatment.
* Uncontrolled hypertension.
* Any other co-morbidity that would compromise the validity of the study or the safety of the participant such as heart failure, clinically apparent cardiovascular disease.
* Volunteers on anti-coagulants such as warfarin and factor Xa inhibitors will not undergo adipose tissue biopsy.
* Unable to give informed consent.
* Previous bariatric surgery.
* Unable to undergo fMRI due to:

  * Claustrophobia.
  * Pacemaker, metal implant, clips, implanted device, shrapnel or bullet, metal in eyes that precludes magnetic resonance imaging.
  * Significant structural abnormality on magnetic resonance brain scan

Where this trial is running

London, Greater London

• NIHR/Wellcome Trust Imperial CRF, Hammersmith Hospital — London, Greater London, United Kingdom (Recruiting)

Study contacts

• Principal investigator: Stephen R Bloom, FRS FRCP MD — Imperial College London
• Study coordinator: Tricia Tan, MBChB MRCP

Conditions Obesity; Type 2 Diabetes