Assessment of Insulin Resistance, NAFLD, Predictors of CV Morbidity, and Subcutaneous Adipose and Visceral Adipose Gene Expression in Patients Undergoing Gastric Bypass Surgery

Assessment of Insulin Resistance, Non-Alcoholic Fatty Liver Disease, Predictors of Cardiovascular Morbidity, and Subcutaneous Adipose and Visceral Adipose Gene Expression in Patients Undergoing Gastric Bypass: Development of a New Paradigm in Defining "Morbid Obesity" and in the Application of Bariatric Surgery

The purpose of this research is to further study the effect weight loss after gastric bypass surgery has on the heart and blood pressure and on how the body uses or metabolizes the sugars, fats and proteins we eat. Additionally, the researchers want to study fat tissue for gene patterns which may be responsible for where we carry fat on our bodies, as well as look carefully at a possible link between adipose tissue and insulin resistance. The researchers also want to evaluate the liver for the presence of fatty liver, which is common in people with obesity and is associated with insulin resistance, as well as study the liver for gene patterns which may be associated with non-alcoholic liver disease.

Evaluating cardiovascular function and endocrine function before and after gastric bypass surgery, as well as studying adipose and liver tissue may help us understand the link between obesity, insulin resistance, fatty liver disease, high blood pressure and health problems such as diabetes and heart disease. Consequently, this may help in the future by identifying those who will benefit most from gastric bypass surgery.

Study Overview

• Status: Completed
• Conditions: Insulin Resistance; Morbid Obesity; Non-Alcoholic Fatty Liver Disease

Detailed Description

Obesity is associated with insulin resistance and diabetes. Since both of these conditions have been implicated in cardiovascular complications, this association may explain obesity related illnesses and deaths. Gastric bypass is considered the "gold standard" surgical weightloss procedure and has been demonstrated to cure diabetes and insulin resistance. Some severely obese patients, however, have normal insulin-glucose metabolism. The differences in metabolic healthy in severely obese individuals has not been fully recognized or understood. This research will study insulin-glucose metabolism in a population of severely obese individuals undergoing gastric bypass. This investigation is based on the following hypotheses:

1. Severely obese individuals can be categorized by degree to which insulin-glucose homeostasis is impaired.
2. The degree of insulin resistance correlates with risk for cardiovascular disease. Weight loss in obese individuals with insulin resistance, will correlate with improvement in parameters associated with cardiovascular disease. Obese individuals with better insulin sensitivity will not have a high risk for cardiovascular disease and therefore will not experience this risk reduction in cardiovascular disease.
3. Insulin resistance is a consequence of pathological storage of excess energy intake; therefore, individuals who are insulin resistant and obese will differ from individuals who are obese, but not insulin resistant with regards to gene expression in subcutaneous adipose tissue and visceral adipose tissue.

Subjects will be studied for evidence of end organ dysfunction and predictors of morbidity and mortality preoperatively and postoperatively. Additionally, gene expression in the subcutaneous and visceral adipose depots of subjects will be studied

• Study Type: Observational
• Enrollment (Actual): 61

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Worcester, Massachusetts, United States, 01655
      • UMass Memorial Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Severely obese patients undergoing gastric bypass surgery

Description

Inclusion Criteria:

• Morbid Obesity
• Scheduled to undergo gastric bypass surgery

Exclusion Criteria:

• Pregnancy (would not be candidate for surgery)
• Nursing (would not be candidate for surgery)

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Severely Obese; Severely obese individuals scheduled to undergo gastric bypass surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Improvement of insulin resistance and/or diabetes	Two weeks postoperatively, Six months postoperatively, One year postoperatively

Secondary Outcome Measures

Outcome Measure	Time Frame
Improvement of cardiovascular risk factors	Two weeks postoperatively, Six months postoperatively, One year postoperatively

Collaborators and Investigators

• Sponsor: University of Massachusetts, Worcester

Study record dates

Study Major Dates

• Study Start: November 1, 2006
• Primary Completion (Actual): May 1, 2012
• Study Completion (Actual): May 1, 2012

Study Registration Dates

• First Submitted: November 3, 2009
• First Submitted That Met QC Criteria: November 3, 2009
• First Posted (Estimate): November 5, 2009

Study Record Updates

• Last Update Posted (Estimate): August 24, 2012
• Last Update Submitted That Met QC Criteria: August 23, 2012
• Last Verified: August 1, 2012

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Glucose Metabolism Disorders; Metabolic Diseases; Overnutrition; Nutrition Disorders; Overweight; Body Weight; Hyperinsulinism; Liver Diseases; Obesity; Fatty Liver; Insulin Resistance; Non-alcoholic Fatty Liver Disease; Obesity, Morbid
• Other Study ID Numbers: H-12082