search
Back to results

Study of Sildenafil Citrate on Insulin Resistance in African American

Primary Purpose

Metabolic Syndrome, Obesity

Status
Completed
Phase
Phase 1
Locations
United States
Study Type
Interventional
Intervention
Sildenafil
Placebo
Sponsored by
Vanderbilt University Medical Center
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional other trial for Metabolic Syndrome focused on measuring African American, Women, Metabolic Syndrome, Endothelial function, Sildenafil citrate

Eligibility Criteria

18 Years - 60 Years (Adult)FemaleDoes not accept healthy volunteers

Inclusion Criteria:

  • Race will be self-defined, but only subjects who report both parents of the same race will be included.
  • Age 18-60 years old.
  • The investigators will recruit subjects with wide range of BMI 30-45 kg/m2.
  • Subjects who have metabolic syndrome or who have a fasting insulin >13. The diagnosis include 3 of the following:

Fasting blood glucose of greater than 100 Triglyceride levels of greater than 150 HDL cholesterol of less than 50 in women Blood pressure of at least 130/85, or on blood pressure medicine Waist girth of more than 35 inches in women. Subjects of childbearing potential will be required to have a negative serum/urine pregnancy test. In addition, they will be asked to use a reliable contraceptive method prior to enrollment as determined by the PI (Dr. Cyndya Shibao).

Exclusion Criteria:

  • Previous allergic reactions to any of the study medication (sildenafil) or inability to take study medications as prescribed during the course of the study.
  • Type 1 or 2 diabetes mellitus as defined by a fasting glucose of 126 mg/dl or greater.
  • Use of antidiabetic medication (insulin, metformin, sulfonylurea, troglitazone)
  • Cardiovascular disease such as myocardial infarction within 6 months prior to enrollment, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third degree heart block, mitral valve stenosis, aortic stenosis or hypertrophic cardiomyopathy.
  • Current smokers.
  • Significant weight change >5% from baseline in the past three months.
  • Pregnancy or breast-feeding.
  • History of serious neurological disease such as cerebral hemorrhage stroke, transient ischemic attack.
  • History or presence of immunological or hematological disorders.
  • Clinical significant gastrointestinal impairment that could interfere with drug absorption.
  • Impaired hepatic function (aspartate amino transaminase [AST] and/or alanine amino transaminase [ALT] >1.5X upper limit of normal range).
  • Impaired renal function (estimated glomerular filtration rate (eGFR) of <60mL/min).
  • Any underlying or acute disease requiring regular medication which could possibly pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult.
  • History of alcohol or drug abuse.
  • Mental conditions rendering the subject unable to understand the nature, scope and possible consequences of the study.
  • Inability to comply with the protocol, e.g. uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study.
  • Patients must not be taking nitratest in any form (e.g., nitroglycerin, isosorbide dinitrate, nitroprusside, and others) during this study
  • Patients on alpha-blocking drugs (doxazosin, terazosin , or prazosin) will be excluded
  • Patients on protease inhibitors (ritonavir and others) will be excluded

Sites / Locations

  • Vanderbilt University

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Placebo Comparator

Arm Label

Sildenafil

Placebo

Arm Description

Sildenafil 20 mg three times a day

placebo

Outcomes

Primary Outcome Measures

Insulin Sensitivity
insulin sensitivity as measured by frequently sampled intravenous glucose tolerance test

Secondary Outcome Measures

Endothelial Function
Endothelial function was measured with flow mediated dilation, percent change

Full Information

First Posted
April 11, 2011
Last Updated
February 22, 2017
Sponsor
Vanderbilt University Medical Center
Collaborators
National Heart, Lung, and Blood Institute (NHLBI), Pfizer
search

1. Study Identification

Unique Protocol Identification Number
NCT01334554
Brief Title
Study of Sildenafil Citrate on Insulin Resistance in African American
Official Title
Effect of Sildenafil Citrate on Insulin Resistance and Endothelial Function in Obese African American Women
Study Type
Interventional

2. Study Status

Record Verification Date
February 2017
Overall Recruitment Status
Completed
Study Start Date
April 2011 (undefined)
Primary Completion Date
August 2013 (Actual)
Study Completion Date
August 2013 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Vanderbilt University Medical Center
Collaborators
National Heart, Lung, and Blood Institute (NHLBI), Pfizer

4. Oversight

Data Monitoring Committee
Yes

5. Study Description

Brief Summary
Obesity has a greater detrimental impact on the health of African American women than on any other racial or gender group. Nearly 80% of African American women are overweight or obese in the United States. Hypertension and insulin resistance are more prevalent among African American women as compared to men and Caucasians. These conditions put them at increased risk for the development of diabetes mellitus and cardiovascular disease. Recent studies have reported that a substance named Nitric Oxide (NO)may have some beneficial effect on how the body handles blood sugar and blood pressure. Of interest,some studies have shown that African Americans have decreased function of NO in their blood vessels. In this study proposal the investigators will test if increasing NO function with a PDE-5 inhibitor (sildenafil citrate) will improve pre-diabetes and the health of the inner layer of the blood vessels in obese African American women.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Metabolic Syndrome, Obesity
Keywords
African American, Women, Metabolic Syndrome, Endothelial function, Sildenafil citrate

7. Study Design

Primary Purpose
Other
Study Phase
Phase 1, Phase 2
Interventional Study Model
Parallel Assignment
Masking
ParticipantCare ProviderInvestigatorOutcomes Assessor
Allocation
Randomized
Enrollment
46 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Sildenafil
Arm Type
Experimental
Arm Description
Sildenafil 20 mg three times a day
Arm Title
Placebo
Arm Type
Placebo Comparator
Arm Description
placebo
Intervention Type
Drug
Intervention Name(s)
Sildenafil
Other Intervention Name(s)
Revatio
Intervention Description
20 mg three times a day.
Intervention Type
Drug
Intervention Name(s)
Placebo
Intervention Description
No active drug
Primary Outcome Measure Information:
Title
Insulin Sensitivity
Description
insulin sensitivity as measured by frequently sampled intravenous glucose tolerance test
Time Frame
Insulin sensitivity measured at baseline and 4 weeks after the intervention
Secondary Outcome Measure Information:
Title
Endothelial Function
Description
Endothelial function was measured with flow mediated dilation, percent change
Time Frame
Difference between FMD at baseline and 4 weeks

10. Eligibility

Sex
Female
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
60 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Race will be self-defined, but only subjects who report both parents of the same race will be included. Age 18-60 years old. The investigators will recruit subjects with wide range of BMI 30-45 kg/m2. Subjects who have metabolic syndrome or who have a fasting insulin >13. The diagnosis include 3 of the following: Fasting blood glucose of greater than 100 Triglyceride levels of greater than 150 HDL cholesterol of less than 50 in women Blood pressure of at least 130/85, or on blood pressure medicine Waist girth of more than 35 inches in women. Subjects of childbearing potential will be required to have a negative serum/urine pregnancy test. In addition, they will be asked to use a reliable contraceptive method prior to enrollment as determined by the PI (Dr. Cyndya Shibao). Exclusion Criteria: Previous allergic reactions to any of the study medication (sildenafil) or inability to take study medications as prescribed during the course of the study. Type 1 or 2 diabetes mellitus as defined by a fasting glucose of 126 mg/dl or greater. Use of antidiabetic medication (insulin, metformin, sulfonylurea, troglitazone) Cardiovascular disease such as myocardial infarction within 6 months prior to enrollment, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third degree heart block, mitral valve stenosis, aortic stenosis or hypertrophic cardiomyopathy. Current smokers. Significant weight change >5% from baseline in the past three months. Pregnancy or breast-feeding. History of serious neurological disease such as cerebral hemorrhage stroke, transient ischemic attack. History or presence of immunological or hematological disorders. Clinical significant gastrointestinal impairment that could interfere with drug absorption. Impaired hepatic function (aspartate amino transaminase [AST] and/or alanine amino transaminase [ALT] >1.5X upper limit of normal range). Impaired renal function (estimated glomerular filtration rate (eGFR) of <60mL/min). Any underlying or acute disease requiring regular medication which could possibly pose a threat to the subject or make implementation of the protocol or interpretation of the study results difficult. History of alcohol or drug abuse. Mental conditions rendering the subject unable to understand the nature, scope and possible consequences of the study. Inability to comply with the protocol, e.g. uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study. Patients must not be taking nitratest in any form (e.g., nitroglycerin, isosorbide dinitrate, nitroprusside, and others) during this study Patients on alpha-blocking drugs (doxazosin, terazosin , or prazosin) will be excluded Patients on protease inhibitors (ritonavir and others) will be excluded
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Cyndya Shibao, MD
Organizational Affiliation
Vanderbilt University
Official's Role
Principal Investigator
Facility Information:
Facility Name
Vanderbilt University
City
Nashville
State/Province
Tennessee
ZIP/Postal Code
37232
Country
United States

12. IPD Sharing Statement

Plan to Share IPD
No
Citations:
PubMed Identifier
26541392
Citation
Marinos A, Celedonio JE, Ramirez CE, Gottlieb J, Gamboa A, Hui N, Yu C, Stein CM, Biaggioni I, Shibao CA. Time-Course Analysis of Flow Mediated Dilation for the Evaluation of Endothelial Function After a High-Fat Meal in African Americans. J Am Heart Assoc. 2015 Nov 5;4(11):e002388. doi: 10.1161/JAHA.115.002388.
Results Reference
derived

Learn more about this trial

Study of Sildenafil Citrate on Insulin Resistance in African American

We'll reach out to this number within 24 hrs