Effects of Bariatric Surgery on Insulin
|First Received Date ICMJE||September 25, 2007|
|Last Updated Date||September 26, 2012|
|Start Date ICMJE||September 2007|
|Primary Completion Date||Not Provided|
|Current Primary Outcome Measures ICMJE||Not Provided|
|Original Primary Outcome Measures ICMJE||Not Provided|
|Change History||Complete list of historical versions of study NCT00535600 on ClinicalTrials.gov Archive Site|
|Current Secondary Outcome Measures ICMJE||Not Provided|
|Original Secondary Outcome Measures ICMJE||Not Provided|
|Current Other Outcome Measures ICMJE||Not Provided|
|Original Other Outcome Measures ICMJE||Not Provided|
|Brief Title ICMJE||Effects of Bariatric Surgery on Insulin|
|Official Title ICMJE||Effects of Bariatric Surgery on Changes in Insulin Secretion and Insulin Action|
This study, conducted at the NIH Clinical Research Unit (CRU) at the Phoenix Indian Medical Center, will compare the effects of two methods of bariatric surgery, the adjustable BAND and Roux-en-Y gastric bypass, on insulin. Bariatric surgery is a treatment for achieving and maintaining weight loss. The study will look at how this surgery might improve how insulin (a hormone important for regulating blood sugar levels) is made and works in the body and the possible role of changes in other hormones produced by the gut (stomach and intestines).
People between 18 and 50 years of age who are scheduled to have either laparoscopic adjustable BAND or Roux-en-Y gastric bypass surgery may be eligible for this study. Candidates are screened about 4 to 6 weeks before their surgery with a medical history, blood tests and an oral glucose tolerance test for diabetes.
Participants spend 4 days at the CRU or 2 days overnight and an out-patient visit approximately 4 to 6 weeks before their surgery and again 3 to 6 weeks after their surgery. They return for a 4-6 hour visit at the CRU at 6 months, 1 and 2 years after surgery and for half-day outpatient visits at 3, 4 and 5 years after surgery for the following procedures:
Bariatric surgery is a treatment for obesity that, in many cases, also improves fasting blood sugar levels even in patients with type 2 diabetes (T2DM) - within days or weeks after surgery . Both inability to use insulin (insulin resistance) and inability to make enough insulin when needed (impaired insulin secretion) must be present for T2DM to occur, and both have been reported to improve after bariatric surgery. It is generally thought that the immediate improvement in blood sugar levels, including remission of T2DM or "prediabetes" in many patients, following bariatric surgery is due to the markedly reduced intake of calories. However, it is not known why blood sugar levels before and after meals tend to improve earlier and to a greater extent in patients who have a Roux en-Y gastric bypass (RYGB) procedure than in patients who have either the adjustable gastric banding (BAND) or sleeve gastrectomy (SG) procedure. It has been proposed that the surgical alteration of the gut and subsequent re-routing of food that occurs with RYGB procedure results in unique changes in how the gut and pancreas (the organ that secretes insulin) respond to food and that these changes are also related to improved insulin resistance and/or secretion.
The purpose of this protocol is to study, before and after surgery, volunteers who either have normal or impaired ("pre-diabetic") blood sugar regulation and who have been approved to undergo either elective RYGBP, BAND or SG bariatric surgery (n=16 each per surgery group, total = 48 individuals with normal blood sugars; n= 10 each per surgery group, total = 30 individuals with prediabetes). The primary aims are to compare the early effects of the BAND, SG and RYGBP procedures on: a) the ability to maintain blood sugar levels, b) how much insulin is made (secretion) and works (insulin action) in the body, and c) responses of gut and pancreas hormones to a meal test before any significant weight loss occurs after surgery. To achieve these goals, we initially will screen volunteers at the NIH Clinical Research Unit in Phoenix approximately 4-6 weeks prior to surgery (1-day outpatient visit) to determine oral glucose tolerance status (OGTT). Within 3 weeks (1-4 weeks prior to surgery), subjects will then be admitted (4-day in-patient stay) or a 2 day overnight stay and an outpatient (4-6 hour) visit to measure weight, body fatness (DXA scan), waist circumference, insulin resistance, insulin secretion, fasting blood sugar and hemoglobin A1c (HbA1c; a substance that indicates how well the body keeps overall blood sugar levels in a normal range), and plasma hormone responses of the gut and pancreas to a standard meal test. These measurements will be repeated at 3-6 weeks following surgery.
Secondary aims are to: 1) compare long-term effects (up to 5 years) of BAND, SG or RYGBP surgery on fasting blood sugar and HbA1c levels, 2) determine if these levels are related to the responses of gut and pancreas hormones during a meal test, and 3) determine whether pre-op or early post-op measures of insulin secretion, insulin action, or responses of gut and pancreas hormones to a meal can predict long-term levels of fasting blood sugar and HbA1c after accounting for changes in weight or body fat. To achieve these goals, subjects will return to the NIH CRU (out-patient, 4-6 hour visit) at 6, 12, and 24 months after surgery to have repeat measurements of body weight, fatness (DXA, non-contrast MRI of waist and thigh), waist circumference, fasting blood sugar and HbA1c levels and the gut and pancreatic hormone responses to a meal test. Thereafter, subjects will have annual outpatient measurements of body weight, body fat and fasting blood sugar and HbA1c levels at 3, 4 and 5 years after surgery.
|Study Type ICMJE||Observational|
|Study Design ICMJE||Time Perspective: Prospective|
|Target Follow-Up Duration||Not Provided|
|Sampling Method||Not Provided|
|Study Population||Not Provided|
|Intervention ICMJE||Not Provided|
|Study Group/Cohort (s)||Not Provided|
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
|Recruitment Status ICMJE||Recruiting|
|Estimated Enrollment ICMJE||72|
|Completion Date||Not Provided|
|Primary Completion Date||Not Provided|
|Eligibility Criteria ICMJE||
Because of the indications for bariatric surgery, many potential subjects will have underlying co-morbidities associated with obesity. For this protocol, subjects will be excluded for the following:
|Ages||18 Years and older|
|Accepts Healthy Volunteers||Yes|
|Location Countries ICMJE||United States|
|NCT Number ICMJE||NCT00535600|
|Other Study ID Numbers ICMJE||999907226, 07-DK-N226|
|Has Data Monitoring Committee||Not Provided|
|Responsible Party||Not Provided|
|Study Sponsor ICMJE||National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)|
|Collaborators ICMJE||Not Provided|
|Information Provided By||National Institutes of Health Clinical Center (CC)|
|Verification Date||September 2012|
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