Effect of Abdominal Obesity on Heart Metabolism and Function

The recruitment status of this study is unknown because the information has not been verified recently.
Verified May 2011 by Washington University School of Medicine.
Recruitment status was  Recruiting
Sponsor:
Collaborator:
Information provided by:
Washington University School of Medicine
ClinicalTrials.gov Identifier:
NCT00572624
First received: December 12, 2007
Last updated: May 11, 2011
Last verified: May 2011
  Purpose

Obesity is one of the most widespread health problems of today, with more than 61 million adult Americans considered obese. Abdominal obesity (AO), in particular, is associated with an increased chance of cardiac diseases, such as coronary artery disease, and related risk factors, such as high blood pressure and type 2 diabetes mellitus (T2DM). Despite the known association between AO and cardiac disease, the mechanisms responsible for this relationship are still not well understood. Recent obesity studies have indicated that increased delivery of fats to the heart may play a role in heart function impairments. This study will evaluate the impact of AO on the human heart's use of fats for energy and on heart function.


Condition Intervention
Obesity
Diabetes Mellitus, Type 2
Behavioral: Weight Loss Management Program

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Altered Myocardial Fatty Acid Metabolism In Obesity

Resource links provided by NLM:


Further study details as provided by Washington University School of Medicine:

Primary Outcome Measures:
  • Association between AO-related changes in myocardial fatty acid metabolism and abnormalities in left ventricular systolic and diastolic function [ Time Frame: Measured at Year 5 ] [ Designated as safety issue: No ]
  • Effect of significant weight loss (10% of body weight) on myocardial fatty acid and glucose metabolism in relation to whole-body fatty acid and glucose kinetics [ Time Frame: Measured at Year 5 ] [ Designated as safety issue: No ]
  • Effects of changes in myocardial substrate metabolism that occur with weight loss on left ventricular systolic and diastolic function [ Time Frame: Measured at Year 5 ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Alterations in the response of myocardial fatty acid and glucose metabolism to increased insulin availability and how the potential alterations relate to whole-body fatty acid and glucose kinetics [ Time Frame: Measured at Year 5 ] [ Designated as safety issue: No ]
  • Impact of increased delivery of fatty acids on myocardial fatty acid and glucose metabolism in relation to whole body fatty acid and glucose kinetics [ Time Frame: Measured at Year 5 ] [ Designated as safety issue: No ]
  • Association between the myocardial metabolic response and changes in left ventricular systolic and diastolic function [ Time Frame: Measured at Year 5 ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples With DNA

1 tablespoon of blood with DNA


Estimated Enrollment: 136
Study Start Date: June 2003
Estimated Study Completion Date: December 2011
Estimated Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
1
Participants characterized as overweight
Behavioral: Weight Loss Management Program
Selected overweight participants will set a goal of 10% body weight loss over a 6-month period, followed by a 1- to 2-month weight loss stabilization period. After the stabilization period, participants will undergo repeat abdominal fat and insulin sensitivity studies and imaging tests.
2
Participants characterized as lean

Detailed Description:

Obesity is defined as having a high amount of excess body fat. Millions of people worldwide meet the criteria for obesity, making it one of the most pressing current health issues. The more body fat a person has, the more susceptible that person is to a number of life threatening diseases, including heart disease, type 2 diabetes, gallstones, certain cancers, and high blood pressure. A variety of factors can lead to obesity. These factors include family history and genetics, physical inactivity, metabolism, hormone imbalance, and environment. Past research suggests that an increased availability of fats in the body leads to increased fat uptake by the heart. The heart only needs a certain amount of fat for energy, which leaves the remaining fat in the heart tissue, possibly impairing proper heart function. However, more information on the mechanisms behind the effects of fats on heart metabolism is needed. This study will evaluate the impact of AO on the human heart's use of fats for energy and on heart function.

This study will enroll both overweight and lean participants who will attend 4 to 7 study visits. Visit 1 will consist of various screening tests, including a medical history, physical exam, pregnancy test if applicable, routine blood test, and an echocardiogram (ECHO) performed before and during exercise.

Visit 2 will consist of an abdominal fat and insulin sensitivity study. This will entail a magnetic resonance imaging (MRI) test to image the heart and stomach, a dual energy x-ray absorptiometry (DEXA) scan to measure total body fat and muscle content, and an insulin sensitivity test to measure how well the hormone insulin controls blood sugar. The latter test will require multiple blood draws over a 3-hour period.

Visits 3 and 4 will occur over a 2-week period. Both visits will consist of an overnight stay at the General Clinical Research Center (GCRC) followed by a day of imaging studies. During Visit 3, participants will first undergo a 4-hour whole body metabolism study, which will include injection of a nonradioactive tracer through previously placed IVs, blood draws, and breathing into a machine for approximately 15 minutes. Participants will then undergo a positron emission tomographic (PET) heart metabolism study, which will also involve tracer injections and blood draws. A resting ECHO test will also be done during the PET study. Participants will be asked for permission to store a sample of their blood for a period of up to 10 years to be used in future research studies on the heart. During Visit 4, participants will undergo repeat tests from the third visit, except the PET study will evaluate the heart's ability to use sugars instead of fats. This will complete the study visits for all lean participants and some overweight participants and will entail 4 weeks of participation.

Overweight participants may be asked to attend an additional three study visits during an 8-month weight management program at Washington University School of Medicine. Participants will aim to lose 10% of their body weight over a 6-month period and to maintain that weight loss for another 1- to 2-month stabilization period. At the end of the stabilization period, participants will undergo repeat abdominal fat and insulin sensitivity studies during Visit 5, repeat whole body metabolism and heart metabolism studies during Visit 6, and repeat whole body metabolism and glucose heart metabolism studies during Visit 7.

  Eligibility

Ages Eligible for Study:   18 Years to 45 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

The study population will include both overweight and lean subjects.

Criteria

Inclusion Criteria:

  • Class II abdominal obesity body mass index (BMI) between 35 kg/m2 and 39.9 kg/m2; waist circumference of greater than 90 cm in women and greater than 105 cm in men
  • Diagnosis of type 2 diabetes
  • Sedentary lifestyle

Exclusion Criteria:

  • History of cardiovascular disease
  • Regular exerciser
  • Occupy a strenuously active job
  • No evidence of inducible myocardial ischemia on resting/stress ECHO
  • No risk factors of coronary artery disease, heart valve disease, or left ventricular dysfunction
  • Left ventricular hypertrophy (based on measure in left ventricular mass index)
  • No evidence of coronary artery disease based on clinical parameters or on rest/stress ECHO
  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: NCT00572624

Contacts
Contact: Debi Delano, MSN 314-747-3876 delanod@mir.wustl.edu
Contact: Kitty Krupp, RN 314-747-0183 kruppk@mir.wustl.edu

Locations
United States, Missouri
Washington University Medical School Recruiting
St. Louis, Missouri, United States, 63110
Principal Investigator: Robert Gropler, MD         
Sub-Investigator: Linda Peterson, MD         
Sub-Investigator: Samuel Klein, MD         
Sub-Investigator: Pilar Herrero, MS         
Sub-Investigator: Victor Davila, MD         
Sponsors and Collaborators
Washington University School of Medicine
Investigators
Principal Investigator: Robert Gropler, MD Washington University Medical School
  More Information

Publications:
Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Robert Gropler, MD, Washington University Medical School
ClinicalTrials.gov Identifier: NCT00572624     History of Changes
Other Study ID Numbers: 488, P01HL013851-43, P01 HL013851-43, IRB# 03-0395, RDRC# 498F, GCRC# 915, 22 3272 52136
Study First Received: December 12, 2007
Last Updated: May 11, 2011
Health Authority: United States: Federal Government

Keywords provided by Washington University School of Medicine:
Abdominal Obesity
Heart Metabolism
Type II Diabetes Mellitus
PET
Fatty Acid

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Nutrition Disorders
Obesity
Obesity, Abdominal
Overnutrition
Overweight
Body Weight
Signs and Symptoms

ClinicalTrials.gov processed this record on August 26, 2014