The purpose of this study is to learn how uterine fibroids may be connected to heart disease and high blood pressure. It is not known what causes fibroids, but they frequently occur in women who also have high blood pressure, heart disease, and stroke. The investigators of this study want to learn if certain changes in the blood vessels or nerve activity can put women at risk for these diseases and for fibroids.
The investigators are inviting women, 25-50 years old, who have not gone through menopause to participate in this study. The investigators are looking for some women with uterine fibroids and some without uterine fibroids based on ultrasound or MRI. If the patients have not had a recent ultrasound or MRI of the uterus, a physician can provide one. Individuals cannot participate if they have high blood pressure, diabetes, or disease in the kidneys, lungs, or blood vessels. Also, individuals who smoke, have high cholesterol, or are obese (BMI is higher than 30) cannot participate. Certain medications, including high blood pressure medications, beta-blockers and anti-depressants, will also limit potential patient participation. The investigators would be happy to review medications for potential participants. Screen Day: One of the members of the research team will review the study and the informed consent document with the patient. The patient will have their height, weight, blood pressure, pulse and respirations measured. The patient will also complete three questionnaires. If the patient has not had an ultrasound of the uterus in the last 12 months, a physician will complete one for her. Study Day: The patient will need to fast overnight (no eating or drinking). The investigators will draw a blood sample and then do a series of tests on the participant's blood vessels. For some of the tests, medication will be given through an IV. The investigators will also test nerve activity in the nerve on the outer aspect of the leg.
Study Type
OBSERVATIONAL
Enrollment
28
A catheter will be placed in the brachial artery by a physician on the study day.
Acetylcholine will be infused into the brachial catheter while blood flow levels in the forearm are measured. Acetylcholine will be infused at the following doses: 1.0, 2.0, 4.0, and 8.0 ug/100 ml tissue/min for 2 minutes each.
Nitroprusside will be infused into the brachial catheter while blood flow levels in the forearm are measured. Nitroprusside will be infused at the following doses: 0.25, 0.5, 1.0, and 2.0 ug/100 ml tissue/min for 2 minutes each.
Mayo Clinic
Rochester, Minnesota, United States
Baseline systolic, diastolic, and mean blood pressures
Time frame: One day (study day)
Baseline sympathetic nerve activity
Nerve "burst" activity will be measured across 10 minutes.
Time frame: One day (study day)
Changes in forearm blood flow levels in response to acetylcholine infusion
Time frame: One day (study day)
Changes in forearm blood flow levels in response to nitroprusside infusion
Time frame: One day (study day)
Changes in forearm blood flow levels in response to norepinephrine infusion
Time frame: One day (study day)
Change in blood pressure in response to infusions of nitroprusside and phenylephrine
An infusion of nitroprusside will be given, followed by an infusion of phenylephrine one minute later.
Time frame: One day (study)
Pulse wave velocity (an index of vessel stiffness)
Time frame: One day (study day)
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Norepinephrine will be infused into the brachial catheter while blood flow levels in the forearm are measured. Norepinephrine will be infused at the following doses: 1.0, 2.0, 4.0, and 8.0 ug/100 ml tissue/min for 2 minutes each.
A single dose of nitroprusside (100 ug) will be infused through an IV; one minute later, a single dose of phenylephrine (150 ug) will be infused.