Study of Sildenafil Citrate on Insulin Resistance in African American

NCT ID: NCT01334554

Last Updated: 2017-03-27

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 46 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2011-04-30
• Study Completion Date: 2013-08-31

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.

Conditions

Metabolic Syndrome; Obesity

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: QUADRUPLE

Study Groups

Sildenafil

Sildenafil 20 mg three times a day

Group Type: EXPERIMENTAL

Sildenafil

Intervention Type: DRUG

20 mg three times a day.

Placebo

placebo

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: DRUG

No active drug

Interventions

Sildenafil

20 mg three times a day.

Intervention Type: DRUG

Placebo

No active drug

Intervention Type: DRUG

Other Intervention Names

Revatio

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

National Heart, Lung, and Blood Institute (NHLBI)

NIH

Sponsor Role: collaborator

Pfizer

INDUSTRY

Sponsor Role: collaborator

Vanderbilt University Medical Center

OTHER

Sponsor Role: lead

Responsible Party

Cyndya Shibao

Assistant Professor of Medicine

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Cyndya Shibao, MD

Role: PRINCIPAL_INVESTIGATOR

Vanderbilt University

Locations

Vanderbilt University

Nashville, Tennessee, United States

Countries

United States

References

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.

Reference Type: DERIVED

PMID: 26541392 (View on PubMed)

Other Identifiers

K23HL103976

Identifier Type: NIH

Identifier Source: secondary_id

View Link

100713

Identifier Type: -

Identifier Source: org_study_id