Incretin Physiology and Beta-cell Function Before and After Weight-loss

Study Overview
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Brief Summary
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To evaluate the impact of laparoscopic adjustable gastric banding (LAGB) on beta-cell function, insulin sensitivity, incretin function, postprandial secretion of incretin hormones (glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)) in morbidly obese patients and to describe the pathophysiological mechanisms involved in the amelioration of glucose homeostasis during long-term weight loss.

Detailed Description
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Morbid obesity represents a serious health issue in Western countries, with a rising incidence and a strong association with increased mortality and serious co-morbidities, such as diabetes. Surgical interventions, such as laparoscopic gastric banding have been developed with the aim of providing a laparoscopic placed device that is safe and effective in generating substantial weight loss. By investigation of the incretin effect, the secretion of GIP and GLP-1, the insulin response and sensitivity and the beta-cell responsiveness to glucose in 10 obese patients without type 2 diabetes before and after laparoscopic gastric banding the aim of this project is describe the pathophysiological mechanisms involved in the amelioration of glucose homeostasis during long-term weight loss.

Official Title
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Incretin Physiology and Beta-cell Function Before and After Weight-loss - Effects of Long-term Weight Loss Following Laparoscopic Adjustable Gastric Banding

Conditions
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Obesity

Intervention / Treatment
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* Other: Oral glucose tolerance test (OGTT), isoglycemic iv. clamp, liquid meal test, gastric emptying rate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Caucasians without type 2 diabetes mellitus Normal OGTT (75 g of glucose) according to WHO's criteria Patients fulfilling the criteria for laparoscopic gastric banding Normal Hemoglobin Informed consent Exclusion Criteria: Liver disease (ALAT > 2 x normal level) Nephropathy (s-creatinin > 130 µM or albuminuria) Relatives (parents/siblings) with T2DM Medical treatment witch cannot be stopped for 12 hours

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| A<br>Obese patients without diabetes with a Body Mass Index > 37 kg/m2 | Other: Oral glucose tolerance test (OGTT), isoglycemic iv. clamp, liquid meal test, gastric emptying rate<br>* OGTT: The test is performed with 50 g of glucose deluded in 300 ml water Isoglycemic iv. clamp: Iv. glucose infusion mimicking the glucose response curves from the OGTT Liquid Meal test: The test is performed with 100g of formula milk deluded in 300 ml. water Gastric Emptying Rate: Paracetamol absorption test.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incretin effect before and one year after gastric banding in obese patients without diabetes |  | One year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| GLP-1 and GIP response curves |  | One year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Incretin effect, Gastric banding, Glucagon, Glucagon-Like Peptide 1, Gastric Inhibitory Peptide, Glucose Intestinal Peptide, Insulin, C-peptide