Effects of Fatty Acid Delivery on Heart Metabolism and Function in Type 2 Diabetes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00577590
Recruitment Status : Completed
First Posted : December 20, 2007
Last Update Posted : February 9, 2018
Information provided by (Responsible Party):
Washington University School of Medicine

Brief Summary:
Type 2 diabetes mellitus (T2DM) is a disease that interferes with the body's proper production and use of insulin, a hormone needed to convert sugar into usable energy. People with T2DM are at a higher risk for certain cardiovascular diseases, including heart disease and stroke. Normal treatments for T2DM target blood sugar levels only, but there is reason to believe that also targeting blood fat levels will improve both sugar metabolism and heart function in people with T2DM. This study will determine the effectiveness of blood-fat lowering treatments along with blood-sugar control treatments in improving heart function and symptoms of people with T2DM.

Condition or disease Intervention/treatment Phase
Diabetes Mellitus, Type II Drug: Lovaza Drug: Metformin Other: Placebo Not Applicable

Detailed Description:

T2DM is the most common type of diabetes. In T2DM, the body does not properly process sugars and, as a result, there is an excess amount of sugar in the blood. Eventually, the high blood sugar levels can lead to heart disease, nerve damage, kidney problems, or blindness. Typical T2DM treatments target maintenance of blood sugar levels. Previous studies on T2DM have indicated that in people who have high amounts of fats in the blood, the body relies more heavily on fats than sugars as an energy source. This dependence on fats for energy has been shown to have a negative effect on heart function. There is reason to believe that lowering the levels of fats in the blood will enhance the ability of the heart and the whole body to efficiently use both fats and sugars as energy sources. This study will evaluate the effectiveness of treatment strategies that are designed to reach target levels of sugar and fat in the blood for treating people with T2DM.

Participation in this double-blind study will last between 4 and 6 months. First, participants will undergo a medical screening and medication adjustment period, expected to last 6 months. The medical screening, lasting about 1 hour, will involve completing a medical history, physical exam, pregnancy test if applicable, and blood test to measure various factors that contribute to diabetes control. Participants will also be asked permission to store 1 tablespoon of their blood for up to 10 years to be used in future studies concerning genetics and heart energy metabolism. During the medication adjustment period, study physicians will adjust the participants' medications, offer advice on diabetes education and nutrition, and record any side effects from the medications. For newly diagnosed T2DM participants, the study physician may recommend medication changes to assure a hemoglobin A1c (HgA1c) level of less than 7.5%. If participants have already achieved this level, they will be asked to continue present medications and to also begin taking the medication metformin for the 30 days before they undergo several imaging studies. Next, participants will complete routine tests that evaluate the pumping function of the heart, including an electrocardiogram (ECG) performed before and during exercise, a body composition study using a dual energy x-ray absorptiometry (DEXA) scan, and a magnetic resonance imaging (MRI) test. Each of these tests will last between 30 and 90 minutes.

After the qualifying tests, participants will return for the first of two separate imaging days that will include the same tests. The second imaging day will occur at the end of the medication period, approximately 2 months after the first imaging day. The first tests will be a whole body metabolism study and a heart metabolism imaging study, performed simultaneously. The whole body metabolism study will involve the injection of two tracers of metabolism, one for glucose and one for fatty acids. The heart metabolism imaging study will involve a positron-emission tomographic (PET) scan to take pictures of the heart and will include blood draws. The final imaging test will be a resting echocardiogram (ECHO) to measure heart function.

Following completion of the first day of imaging tests, participants will be randomly assigned to one of two possible treatment groups: Group A or B. In addition to continuing current medications, both groups will begin taking metformin daily. Group A will also take a pill of Lovaza daily, and Group B will take a matching placebo of Lovaza daily. Participants will be seen monthly for the next 4 months, during which study medication will be distributed and blood pressure, heart rate, weight, and any side effects, such as lower extremity swelling, will be measured. If there is a noticeable increase in swelling, study physicians may adjust medication dosages. During visits at Months 2 and 4, blood samples will be taken to measure liver and organ function and HgA1c. At the completion of the 4-month medication treatment, participants will undergo repeat imaging tests. If needed, participants will be offered the opportunity to attend one or more follow-up visits to re-establish a medication routine.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 146 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Cyclotron Produced Isotopes in Biology and Medicine, Project 3: Specific Aim 1A and 1B Effects of Fatty Acid Delivery on Myocardial Metabolism and Function in Type 2 Diabetes
Study Start Date : October 2003
Actual Primary Completion Date : August 2012
Actual Study Completion Date : September 2012

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Metformin and Lovaza
Participants assigned to take metformin and Lovaza
Drug: Lovaza
Dosage of 4 g to be taken daily for 2 months
Other Name: Omega-3-acid ethyl ester compound

Drug: Metformin
Dosage of at least 1000 mg to be taken daily for 4 months
Other Name: Non-thiazolidinedione (TZD) oral agents

Placebo Comparator: Metformin and Placebo
Participants assigned to take metformin and placebo
Drug: Metformin
Dosage of at least 1000 mg to be taken daily for 4 months
Other Name: Non-thiazolidinedione (TZD) oral agents

Other: Placebo
Placebo is taken along with Metformin

Primary Outcome Measures :
  1. Impact of lowering triglycerides in patients with T2DM; the effect of Lovaza on whole body and myocardial substrate metabolism and function [ Time Frame: Measured at Year 5 ]
    Taking Metformin with Placebo, Metformin with Rosiglitizone, and Metformin with Lovaza to determine the impact of lowering tryglycerides in patients with Type 2 Diabetes Mellitus

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Meets Americans with Disabilities Act (ADA) criteria for T2DM; if newly diagnosed, must have fasting blood glucose greater than 126 mg/dl on two occasions, a random blood glucose greater than 200 mg/dl with symptoms, or a diagnostic oral glucose tolerance test
  • Weight of less than 350 pounds
  • Hemoglobin A1c of equal to or less than 7.5% at study entry or willing to go on one of the following therapies to achieve necessary percentage: metformin monotherapy greater than 1000 mg daily for at least 30 days or metformin greater than 1000 mg daily plus any combination of sulfonylurea, glipizide, or alpha-glucosidase inhibitor
  • Blood pressure less than 140/90 mm Hg at study entry
  • LDL level less than 130 mg/dL if on stable lipid lowering regimen
  • Willing to undergo normal rest/stress (treadmill or dobutamine) echocardiogram
  • If currently taking thyroid replacement therapy, must be on a stable dose of thyroid replacement and must have a thyroid function blood test that is in the normal range
  • Willing to use an effective form of birth control throughout the study

Exclusion Criteria:

  • Received therapy with an insulin sensitizer of the thiazolidinedione class within 6 months prior to study entry
  • Required insulin therapy for more than 2 weeks in the year prior to study entry
  • History of angina, heart attack, coronary artery bypass grafting (CABG), stroke, congestive heart failure (CHF), or peripheral vascular disease (PVD)
  • Known coronary artery disease (CAD) with residual lesions of greater than 50%
  • Current smoker
  • Use or expected use of corticosteroids in any form
  • Serum triglycerides greater than 400 mg/dl on a fasting sample at study entry
  • Any contraindication to a thiazolidinedione (TZD) insulin sensitizer, metformin, or other drugs likely to be used during the study
  • Liver disease with liver function test (LFT) greater than 2 times the upper limit of normal (ULN)
  • Serum creatinine greater than 1.5 mg/dl for women and 1.6 mg/dl for men OR greater than 2+ proteinuria on urine dipstick

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00577590

United States, Missouri
Washington University in St. Louis
Saint Louis, Missouri, United States, 63110
Sponsors and Collaborators
Washington University School of Medicine
Principal Investigator: Robert Gropler, MD Washington University School of Medicine

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Washington University School of Medicine Identifier: NCT00577590     History of Changes
Other Study ID Numbers: 487
First Posted: December 20, 2007    Key Record Dates
Last Update Posted: February 9, 2018
Last Verified: February 2018

Keywords provided by Washington University School of Medicine:
Type II Diabetes Mellitus
Heart Metabolism

Additional relevant MeSH terms:
Diabetes Mellitus
Diabetes Mellitus, Type 2
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Hypoglycemic Agents
Physiological Effects of Drugs