Treating the Endothelium to Restore Insulin Sensitivity

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: NCT00402194
Recruitment Status : Completed
First Posted : November 22, 2006
Results First Posted : September 24, 2013
Last Update Posted : September 24, 2013
Information provided by (Responsible Party):
Indiana University ( Indiana University School of Medicine )

Brief Summary:
A study of 12 weeks' treatment with losartan or placebo, to test the hypothesis that RAS inhibition will improve insulin' vascular actions and therefore improve insulin sensitivity in skeletal muscle.

Condition or disease Intervention/treatment Phase
Obesity Insulin Resistance Impaired Glucose Tolerance Pre-diabetes Drug: Losartan Not Applicable

Detailed Description:
Recent studies suggesting an effect of cardiovascular therapies to prevent diabetes remain unexplained. We hypothesize that these therapies improve vascular endothelial function allowing improved actions of insulin in the vasculature, which comprise a significant portion of insulin's metabolic action. We therefore propose to measure insulin-mediated glucose disposal and insulin-mediated vasodilation before and after 12 weeks' therapy with Losartan (an angiotensin receptor blocker) or placebo, in a randomized design. Subjects will include 28 subjects with impaired glucose tolerance, which is generally accompanied by both insulin resistance and impaired vascular function. With this number of participants we have a 90% chance of showing a statistically significant and clinically meaningful effect of insulin on leg vascular resistance, and an even higher chance of showing a difference in insulin's metabolic effects. Exclusion criteria will include frank hypertension, diabetes, or hypercholesterolemia, and biochemical or other contraindications to losartan therapy. The primary endpoint for statistical analysis will be the invasive measure of insulin-stimulated endothelial function. We anticipate an improvement in both vascular and metabolic measures of insulin action following Losartan therapy but no change from untreated baseline following placebo.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 17 participants
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Treating the Endothelium to Restore Insulin Sensitivity
Study Start Date : June 2005
Actual Primary Completion Date : November 2011
Actual Study Completion Date : March 2012

Resource links provided by the National Library of Medicine

Intervention Details:
  • Drug: Losartan
    Tablet, 100mg, once per day for 3 months

Primary Outcome Measures :
  1. Leg Blood Flow Response to Insulin [ Time Frame: 3 months ]
  2. Insulin-stimulated Leg Glucose Uptake [ Time Frame: 3 months ]

Information from the National Library of Medicine

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Ages Eligible for Study:   20 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Healthy
  • Age 20-55
  • Male and female
  • Obese, defined as Males: BMI >28 or > 30% fat by DEXA scan or Bod Pod; Females: BMI >30 or > 33% fat by DEXA scan or Bod Pod
  • Weight stable over at least 4 months

Exclusion Criteria:

  • Diabetes mellitus (ADA criteria)
  • Age <20 or > 55 yrs
  • Blood pressure >160/90 or < 90/65 mmHg
  • Total cholesterol >240 or LDL cholesterol >160 mg/dL
  • Baseline elevations in AST or ALT > 3X ULN
  • Baseline elevation in creatinine >1.6 ng/mL
  • Unexplained baseline elevation in creatine kinase > 3X ULN
  • Concurrent significant chronic medical illness including, but not limited to, human immunodeficiency virus infection, Syphilis, hepatitis B infection, or hepatitis C infection
  • Pregnancy
  • Known hypersensitivity or intolerance to the study agents

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): NCT00402194

United States, Indiana
Indiana University Hospital GCRC
Indianapolis, Indiana, United States, 46202
Sponsors and Collaborators
Indiana University School of Medicine
Principal Investigator: Kieren J Mather, MD Indiana University

Responsible Party: Indiana University School of Medicine Identifier: NCT00402194     History of Changes
Other Study ID Numbers: IU-IRB-0301-08
First Posted: November 22, 2006    Key Record Dates
Results First Posted: September 24, 2013
Last Update Posted: September 24, 2013
Last Verified: September 2013

Keywords provided by Indiana University ( Indiana University School of Medicine ):
Insulin resistance
Impaired glucose tolerance

Additional relevant MeSH terms:
Insulin Resistance
Glucose Intolerance
Prediabetic State
Glucose Metabolism Disorders
Metabolic Diseases
Diabetes Mellitus
Endocrine System Diseases
Hypoglycemic Agents
Physiological Effects of Drugs
Anti-Arrhythmia Agents
Antihypertensive Agents
Angiotensin II Type 1 Receptor Blockers
Angiotensin Receptor Antagonists
Molecular Mechanisms of Pharmacological Action