Caveolin-1 and Vascular Dysfunction

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: NCT01426529
Recruitment Status : Active, not recruiting
First Posted : August 31, 2011
Last Update Posted : March 23, 2017
National Heart, Lung, and Blood Institute (NHLBI)
National Institutes of Health (NIH)
Information provided by (Responsible Party):
Luminita Pojoga, Brigham and Women's Hospital

Brief Summary:

Caveolin-1 and Vascular Dysfunction

Thank you for your interest in the investigators Blood Pressure Research Study. The National Institutes of Health are sponsoring us to investigate why patients develop high blood pressure, atherosclerosis (hardening of the arteries), and heart disease. There are two parts of the investigators research program. The first part is a screening visit. At this visit you will be given a brief physical exam and will be asked questions concerning your medical history. During the same visit you will have your blood drawn for routine screening and genetic testing. You will also be asked to collect a urine sample for routine screening.

If the doctor finds that you are a healthy candidate you will be invited to participate in the second part of the study. During Phase II, the investigators will perform physiological tests after you are placed on a low salt diet and again after you are placed on a higher salt diet. If you are on blood pressure medication, it may be necessary to discontinue taking your present medication for up to three months before beginning the study. Patients discontinuing their current blood pressure medication may be placed on a different blood pressure medication during this 'washout' period if necessary to maintain blood pressure at pre-study levels.

Once your blood pressure medications are discontinued, you will be closely monitored. If you do not own a home blood pressure monitor, the investigators will provide one for you to use during the study so that you can keep a daily record of your blood pressure readings. The investigators will ask you to call us every three days to report your blood pressure readings. After you have stopped taking your medication, dieticians at the hospital will make you low salt meals to eat at home for about seven days. On the last day of the low salt diet, you will be asked to begin a 24-hour urine collection that you will bring with you when you are admitted to the hospital that evening. That morning, you will be required to come to the Center for Clinical Investigations (CCI) at Brigham and Women's Hospital for a one-hour test to check if your body is in the correct salt balance.

You will return that evening to the CCI where you will be admitted for your study that will occur the next morning. On the morning of your low salt study, the investigators will collect some blood samples. The investigators will also take ultrasound pictures of your heart to see how salt and hormones affect the way your heart and blood vessels functions. These tests will last approximately 5 hours and you will be discharged around 2:00 PM. For the next 5-7 days, you will be placed on a high salt diet. During this diet period, you will eat all your own food, but the investigators will give you some supplements to add to your meals. After 5-7 days on your high salt diet, on the morning of your second admission to the hospital, you will be asked to begin a final 24-hour urine collection. That morning, you will again be required to come to the CCI for a blood test, and you will return later that evening to the inpatient CCI where you will be admitted for your final overnight study. The same study that was done for the low salt diet will be repeated for the high salt study. You will be discharged at around 2:00 p.m. These studies will help to determine if you are salt-sensitive. In addition, the investigators hope to learn more about the hormones that regulate your blood pressure and the genes responsible for regulating those hormones.

You will have the option to spend a second night in the CCI after each diet phase in order to participate in an optional study of the blood vessels in the arm. This study also uses an ultrasound machine. It will last about 2 hours in the morning.

You will be placed back on your initial blood pressure medication (if you are on any) and returned to your regular physician for care. The investigators can also provide clinically relevant information to you.

Condition or disease Intervention/treatment Phase
Hypertension Insulin Resistance Drug: Para-aminohippuric Acid Drug: Angiotensin II Drug: Norepinephrine Phase 1

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 120 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Other
Official Title: Caveolin-1 and Vascular Dysfunction
Actual Study Start Date : October 1, 2010
Estimated Primary Completion Date : October 15, 2017
Estimated Study Completion Date : October 15, 2017

Resource links provided by the National Library of Medicine

Intervention Details:
  • Drug: Para-aminohippuric Acid
    Aminohippurate sodium is an agent to measure effective renal plasma flow (ERPF). It is the sodium salt of para-aminohippuric acid, commonly abbreviated "PAH".
    Other Name: PAH
  • Drug: Angiotensin II
    Angiotensin II (Ang II) is a naturally occurring hormone whose primary purpose is to regulate the body's internal volume. It accomplishes this task by influencing the function of a variety of organs and tissues. It increases aldosterone secretion from the adrenal gland. It causes blood vessels to contract, particularly renal blood vessels, and it modifies the way the heart works.
    Other Names:
    • AngII
    • AII
  • Drug: Norepinephrine
    A hormone that is normally present in your body, which regulates your blood pressure.
    Other Name: NE

Primary Outcome Measures :
  1. Genetic Variation at the Caveolin-1 Locus [ Time Frame: 5 years ]

    We are testing our hypothesis that genetic variation at the cav-1 locus is a determinant of vascular phenotypes in hypertensive subjects. We will recruit hypertensive subjects who will be classified into two groups according to genotype status at rs926198 of CAV-1. Vascular function status will be determined using four markers: renal blood flow (primary endpoint), brachial artery reactivity, aortic compliance, and blood pressure levels.

    We will assess these endpoints before and after two provocations: low vs. high salt intake and AngII infusion.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Ages Eligible for Study:   18 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • age 18-65
  • mild to moderate hypertension
  • no other major illnesses
  • BMI < or equal to 40

Exclusion Criteria:

  • secondary illnesses
  • BMI > 40
  • taking 4 or more anti-hypertensive medications
  • BP >160/100 on screening exam
  • Alcohol intake >12 oz per week
  • Current smoking
  • Recreational drug use
  • use of birth control pills or contraceptive hormone shots

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): NCT01426529

United States, Massachusetts
Brigham and Women's Hospital
Boston, Massachusetts, United States, 02115
Sponsors and Collaborators
Brigham and Women's Hospital
National Heart, Lung, and Blood Institute (NHLBI)
National Institutes of Health (NIH)
Principal Investigator: Luminita Pojoga, PhD Brigham and Women's Hospital

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Luminita Pojoga, Instructor of Medicine, Associate Physiologist, Brigham and Women's Hospital Identifier: NCT01426529     History of Changes
Other Study ID Numbers: 2010P002187
1R01HL104032-01 ( U.S. NIH Grant/Contract )
First Posted: August 31, 2011    Key Record Dates
Last Update Posted: March 23, 2017
Last Verified: March 2017

Additional relevant MeSH terms:
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases
Angiotensin II
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Autonomic Agents
Peripheral Nervous System Agents
Vasoconstrictor Agents
Serine Proteinase Inhibitors
Protease Inhibitors
Enzyme Inhibitors