Glucolipotoxicity and Cardiac Dysfunction in Obesity

The recruitment status of this study is unknown because the information has not been verified recently.
Verified March 2012 by The University of Texas Health Science Center, Houston.
Recruitment status was  Active, not recruiting
Sponsor:
Collaborator:
Information provided by (Responsible Party):
Heinrich Taegtmeyer, The University of Texas Health Science Center, Houston
ClinicalTrials.gov Identifier:
NCT00178633
First received: September 12, 2005
Last updated: March 13, 2012
Last verified: March 2012
  Purpose

To assess changes in cardiac contractile function, as they relate to metabolic parameters, in clinically severe obese patients undergoing bariatric surgery.


Condition
Obesity
Diabetes,
Heart Failure,
Insulin Resistance

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Glucolipotoxicity and Cardiac Dysfunction in Obesity

Resource links provided by NLM:


Further study details as provided by The University of Texas Health Science Center, Houston:

Biospecimen Retention:   Samples Without DNA

Skeletal muscle biopsies, plasma


Enrollment: 43
Study Start Date: October 2004
Estimated Study Completion Date: August 2012
Estimated Primary Completion Date: August 2012 (Final data collection date for primary outcome measure)
Detailed Description:

Obesity is responsible for the death of 300,000 Americans a year. Yet, the effects of over-nutrition on the heart are not well understood. We therefore propose to examine "footprints" of obesity in the heart, and to identify mechanisms leading to impaired cardiac function in animal models, as well as in clinically obese patients undergoing gastric bypass surgery. Special emphasis is placed on the myocardial consequences of deranged glucose and fatty acid metabolism and their potential reversal. The broad objective of this proposal is to test the hypothesis that abnormal accumulation of glucose and fatty acid metabolites results from a loss of synchronization of substrate uptake and oxidation, and leads to glucolipotoxicity and to contractile dysfunction in the heart. The first specific aim will define the process by which excessive fuel supply (beyond the storage capacity of adipocytes) results in accumulation of lipotoxic compounds in the heart and in other organs (e.g. skeletal muscle). In genetic and diet-induced rat models of obesity we shall define the time course of adaptation and maladaptation to excess substrate availability. We shall also define the time course of reversal of obesity-induced changes by food restriction or surgical intervention (gastric bypass). The second specific aim will address potential mechanisms of glucolipotoxicity in heart, as well as skeletal muscle. We shall examine gene expression, PKC activity, protein glycosylation, protein ubiquitinization, and programmed cell death. Selective activation of these different pathways may play a significant role in glucolipotoxicity. The third specific aim will apply insights gained from animal experiments to correlates of glucolipotoxicity in humans. We will test the hypothesis that weight loss reverses the maladaptive response in patients undergoing bariatric weight loss surgery. We will define metabolic indices (BMI, insulin resistance, blood pressure, lipid profile, adipokine levels) and various indices of cardiac function (e.g. echocardiography) in tandem with skeletal muscle biopsies before, as well as three and nine months after surgery. Our long-term goals are to describe metabolic adaptation and maladaptation of the heart in clinically relevant obesity, to transform the concept of glucolipotoxicity from an operational definition to a concrete physiological principle, and to establish a rationale for more effective treatment of obese patients with heart failure.

  Eligibility

Ages Eligible for Study:   18 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

Male and female patients with clinically severe obesity (BMI>40kg/m2)who undergo elective bariatric surgery.

Criteria

Inclusion Criteria:

  • The subjects in this study will represent both male and female patients with clinically severe obesity (BMI > 40kg/m2), who have chosen to undergo elective bariatric surgery. Patients are screened through the University of Texas Houston Bariatric Surgery Center (UTHBSC) and are evaluated for bariatric surgery, defined in this study as small pouch gastric bypass with Roux-en-Y (SPGB), as a means of weight loss. Individuals from diverse ethnic backgrounds between the ages of 18 and 60, with clinically severe obesity, are eligible to be evaluated for bariatric weight loss surgery in the UTHBSC. Candidates considered for the study are patients who not only fulfill the criteria for weight loss surgery, but also demonstrate a high likelihood of complying with the long-term follow-up that is required for a successful study.

Patients who have components of the metabolic syndrome (hypertension, diabetes, and dyslipidemia) will be included if these complications do not preclude a safe operation. .

Exclusion Criteria: Exclusion criteria include age over 70 years, current history of smoking, coronary artery disease, congestive heart failure, ischemic cardiomyopathy, known peripheral vascular disease, severe psychiatric disease, any medical problem or physical contraindication for surgery (as determined by the physician) and pregnancy. This study will be limited to adults since the safety of gastric bypass surgery has not been shown to be safe in children in large clinical trials

-

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00178633

Locations
United States, Texas
University of Texas, Health Sciences Center Houston
Houston, Texas, United States, 77030
Sponsors and Collaborators
The University of Texas Health Science Center, Houston
Investigators
Principal Investigator: Heinrich Taegtmeyer, MD, DPhil University of Texas, Health Sciences Center Houston
  More Information

Publications:

Responsible Party: Heinrich Taegtmeyer, Professor - Internal Medicine, Cardiology, The University of Texas Health Science Center, Houston
ClinicalTrials.gov Identifier: NCT00178633     History of Changes
Other Study ID Numbers: 5RO1 HL073162-02
Study First Received: September 12, 2005
Last Updated: March 13, 2012
Health Authority: United States: Institutional Review Board

Keywords provided by The University of Texas Health Science Center, Houston:
Obesity
Insulin Resistance
Free Fatty Acids
Heart Failure

Additional relevant MeSH terms:
Heart Failure
Insulin Resistance
Obesity
Heart Diseases
Cardiovascular Diseases
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms

ClinicalTrials.gov processed this record on August 25, 2014