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Regression of Fatty Heart by Valsartan Therapy

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ClinicalTrials.gov Identifier: NCT00745953
Recruitment Status : Unknown
Verified August 2009 by University of Texas Southwestern Medical Center.
Recruitment status was:  Recruiting
First Posted : September 3, 2008
Last Update Posted : August 19, 2009
Sponsor:
Collaborator:
Novartis Pharmaceuticals
Information provided by:
University of Texas Southwestern Medical Center

Brief Summary:

Traditionally, obesity is considered an indirect cause of heart disease. Obese individuals typically present with a number of traditional Framingham risk factors (hypertension, dyslipidemia, and type 2 diabetes), predisposing them to heart attacks and subsequent heart failure. However, an emerging body of basic research revisits a hypothesis that fat is a direct cardiotoxin. Under healthy conditions, most triglyceride is stored in fatty tissue (adipocytes) while the amount of triglyceride stored in non-adipocyte tissues (such as the pancreas, the liver, skeletal muscle, and heart) is minimal and very tightly regulated. When this regulation is disrupted, intracellular triglyceride accumulates excessively in these organs ("steatosis") and has been implicated in activating adverse pathways which culminate in irreversible cell death ("lipotoxicity"), leading to several well-recognized clinical syndromes. These include non-alcoholic steatohepatitis (NASH), pancreatic beta-cell failure in type 2 diabetes, and dilated cardiomyopathy.

It has been recently observed that angiotensin II receptor blockers (ARBs) in addition to lowering blood pressure improve insulin sensitivity and decrease the risk for type 2 diabetes. This study will test the above theory in two study groups: Valsartan vs. Hydrochlorothiazide. We hypothesize that in obese humans with elevated myocardial triglycerides, blockade of the renin-angiotensin system (Valsartan group) will reduce myocardial fat with improvement of insulin sensitivity and heart function.


Condition or disease Intervention/treatment Phase
Metabolic Syndrome Lipotoxicity Drug: Valsartan Drug: Hydrochlorothiazide Phase 4

Detailed Description:

Basic science in animal models of genetic obesity have demonstrated that obese, insulin resistant animals have fatty hearts with reduced functional ability. More importantly, insulin sensitizing treatment of prediabetic rats delayed development of diabetes and improved heart function. A primary aim of our laboratory is to translate basic animal research, suggesting that excessive lipid accumulation in the myocardium is toxic, into the clinical setting using cardiac magnetic resonance imaging/spectroscopy technology. The results of this research may identify new biomarkers and drug targets to prevent cardiac disease in obese humans.

We used our novel in vivo magnetic resonance imaging and spectroscopy technique that enables quantification of triglyceride in human myocardium non-invasively, to demonstrate that obese humans like obese animals are characterized by elevated fat in myocardium. We hypothesize that in obese humans with elevated myocardial TG, blockade of the renin-angiotensin system will reduce myocardial fat with improvement of insulin sensitivity and heart function.

The aims of this study are to test if in obese people with impaired glucose tolerance (IGT):

Aim 1) Valsartan treatment will reduce myocardial fat and will improve heart geometry and function,

Aim 2) therapy with thiazide diuretic hydrochlorothiazide (HCTZ) treatment will elevate myocardial fat.

We are planning to test the action of Valsartan versus HCTZ as we expect that these drugs cause opposite metabolic effects. The landmark trial ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) has refocused attention to the thiazide-type diuretics as the first-line therapy for most patients with hypertension. Despite proven reduction in cardiovascular outcomes and low costs, there is on-going concern that one of the major side effect of the thiazides—glucose intolerance—may fuel the current U.S. epidemic of type 2 diabetes. Despite of efficacy and low cost thiazide diuretics are long known to cause insulin resistance, impaired glucose tolerance, and precipitation of overt diabetes.


Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 28 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Regression of Fatty Heart by Valsartan Therapy
Study Start Date : August 2007
Estimated Primary Completion Date : August 2009
Estimated Study Completion Date : August 2009


Arm Intervention/treatment
Active Comparator: Valsartan
This arm will determine if blockade of the renin-angiotensin system reduces myocardial fat levels and improves insulin sensitivity. It consists of 6 visits: visit1 (baseline); visit2 (2 weeks); visit3 (1 month); visit4 (3 month); visit5 (6 month); visit6 (8 month). Visits 1 & 6 will consist of blood tests, glucose tolerance test by FSivGTT, MRS, & 24 hr ambulatory blood pressure monitoring. During visit 1, patients receive automatic blood pressure monitor, OMRON, to record blood pressure between visits. Visits 2 & 3 are needed for the adjustment of medication to the final dose level. During visits 4 & 5, Dr. Price will check subject's status as they continue the medication. In case of uncontrolled blood pressure, Dr. Price will prescribe amlodipine for the additional BP control.
Drug: Valsartan
Valsartan 320mg PO daily for 8 months
Other Name: Diovan

Active Comparator: Hydrochlorothiazide
This arm will determine if thiazide diuretics elevate myocardial triglyceride levels. It consists of 6 visits: visit1 (baseline); visit2 (2 weeks); visit3 (1 month); visit4 (3 month); visit5 (6 month); visit6 (8 month). Visits 1 & 6 will consist of blood tests, glucose tolerance test by FSivGTT, MRS, & 24 hr ambulatory blood pressure monitoring. During visit 1, patients receive automatic blood pressure monitor, OMRON, to record blood pressure between visits. Visits 2 & 3 are needed for the adjustment of medication to the final dose level. During visits 4 & 5, Dr. Price will check subject's status as they continue the medication. In case of uncontrolled blood pressure, Dr. Price will prescribe amlodipine for the additional BP control.
Drug: Hydrochlorothiazide
Hydrochlorothiazide 25mg PO daily for 8 months
Other Name: HCTZ




Primary Outcome Measures :
  1. Myocardial triglyceride levels [ Time Frame: 8 months ]

Secondary Outcome Measures :
  1. Hepatic triglyceride levels, insulin sensitivity, abdominal fat mass [ Time Frame: 8 months ]


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Ages Eligible for Study:   18 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Prediabetic individuals with impaired glucose tolerance (2 hr postprandial glucose > 140mg/dL) or having 3 of 5 Metabolic Syndrome criteria:

    1. Fasting glucose > 100mg/dL;
    2. Waist circumference: men > 102cm, women > 88cm (confirmed with abdominal MRI);
    3. HDL: men < 40mg/dL, women < 50mg/dL;
    4. Triglycerides > 150mg/dL;
    5. Blood pressure > 130/80mmHg;
  • Elevated hepatic triglycerides (>5.5%) and myocardial triglycerides (>0.6%)
  • Elevated blood triglycerides >150mg/dL
  • Age < 50 years

Exclusion Criteria:

  • Type 2 Diabetes mellitus
  • Prior exposure to renin system blockers or HCTZ
  • BP > 160/100mmHg
  • Claustrophobia
  • Metallic implants in body
  • Pregnant or planning to become pregnant
  • Prior exposure to statin medications

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 ClinicalTrials.gov identifier (NCT number): NCT00745953


Contacts
Contact: Angela L Price, MD 214.648.0335 Angela.Price@UTSouthwestern.edu
Contact: Lidia S Szczepaniak, PhD 214.648.6886 Lidia.Szczepaniak@UTSouthwestern.edu

Locations
United States, Texas
University of Texas Southwestern Medical Center Recruiting
Dallas, Texas, United States, 75390
Sponsors and Collaborators
University of Texas Southwestern Medical Center
Novartis Pharmaceuticals
Investigators
Principal Investigator: Ronald G Victor, MD University of Texas Southwestern Medical Center
Study Director: Lidia S Szczepaniak, PhD University of Texas Southwestern Medical Center

Responsible Party: Dr. Ildiko Lingvay, MD, University of Texas Southwestern Medical Center
ClinicalTrials.gov Identifier: NCT00745953     History of Changes
Other Study ID Numbers: IIRP Study US 73
First Posted: September 3, 2008    Key Record Dates
Last Update Posted: August 19, 2009
Last Verified: August 2009

Keywords provided by University of Texas Southwestern Medical Center:
Metabolic syndrome
Lipotoxicity
Insulin sensitivity
Myocardial triglyceride levels
Hepatic triglyceride levels
Magnetic resonance spectroscopy

Additional relevant MeSH terms:
Metabolic Syndrome X
Insulin Resistance
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Valsartan
Hydrochlorothiazide
Antihypertensive Agents
Angiotensin II Type 1 Receptor Blockers
Angiotensin Receptor Antagonists
Molecular Mechanisms of Pharmacological Action
Diuretics
Natriuretic Agents
Physiological Effects of Drugs
Sodium Chloride Symporter Inhibitors
Membrane Transport Modulators