NCT04439370 · University of Minnesota
Autonomic Regulation of Blood Pressure in Premature and Early Menopausal Women
What this study is about
This is a cross-sectional study in which the investigators will determine the impact of premature/early menopause on MSNA, BP and baroreflex sensitivity in younger (≤49 yr old) and older (≥50 yr old) women.
View original scientific description
This is a cross-sectional study in which the investigators will determine the impact of premature/early menopause on MSNA, BP and baroreflex sensitivity in younger (≤49 yr old) and older (≥50 yr old) women. Specifically, aim one will determine mechanisms driving autonomic dysregulation of BP in premature and early menopausal women and aim two will determine mechanisms driving autonomic dysregulation of BP in older menopausal women. The study design outlined below will permit testing of aim one and aim two.
Interventions
DIAGNOSTIC_TEST
Microneurography to measure muscle sympathetic nerve activity (MSNA)
Microneurography is a direct measurement of electrical activity of peripheral sympathetic nerves
DIAGNOSTIC_TEST
Baroreflex sensitivity testing
Two arms of the baroreflex that will be tested in this study are sympathetic and cardiovagal. Static baroreflex is tested during baseline resting conditions and dynamic baroreflex is tested during Valsalva maneuvers.
DIAGNOSTIC_TEST
Sympathoexcitatory Maneuvers
Cold Pressor Test (CPT) and Upper extremity fatiguing contraction with post exercise circulatory occlusion (PECO) will be performed
DIAGNOSTIC_TEST
Blood tests
Serum FSH, estrogen, progesterone, and testosterone will be measured
Primary outcome measures
Muscle Sympathetic Nerve Activity (MSNA) (bursts per minute)
Time frame: 3 hours
Muscle sympathetic nerve activity (MSNA) is a measurement of sympathetic activity. This is measured by two small needles are inserted behind or on the side of the knee, one needle is an acupuncture needle and one needle is a small recording microelectrode (same size as the acupuncture needle). Outcome will be reported in units of bursts per minute.
Muscle Sympathetic Nerve Activity (MSNA) (bursts/100 heart beats)
Time frame: 3 hours
Muscle sympathetic nerve activity (MSNA) is a measurement of sympathetic activity. This is measured by two small needles are inserted behind or on the side of the knee, one needle is an acupuncture needle and one needle is a small recording microelectrode (same size as the acupuncture needle). Outcome will be reported in units of bursts per 100 heart beats.
Cardiac baroreflex sensitivity
Time frame: 3 hours
Baroreflex sensitivity will be derived from electrocardiogram measurements and blood pressure measurements during the baseline rest period and by performing a modified valsalva maneuver which involves exhaling against 30-40 mmHg of pressure over 15 seconds after a normal inhalation. Outcome will be reported in units as ms/mmHg.
Sympathetic baroreflex sensitivity
Time frame: 3 hours
Baroreflex sensitivity will be derived from electrocardiogram measurements and blood pressure measurements during the baseline rest period and by performing a modified valsalva maneuver which involves exhaling against 30-40 mmHg of pressure over 15 seconds after a normal inhalation. Outcome will be reported in units of MSNA bursts/mmHg.
Systolic Blood Pressure (mmHg)
Time frame: 3 hours
Blood pressure is measured using a non-invasive blood pressure cuff secured to the middle or ring finger and reported in units of mmHg.
Diastolic Blood Pressure (mmHg)
Time frame: 3 hours
Blood pressure is measured using a non-invasive blood pressure cuff secured to the middle or ring finger and reported in units of mmHg.
Mean Arterial Blood Pressure (mmHg)
Time frame: 3 hours
Blood pressure is measured using a non-invasive blood pressure cuff secured to the middle or ring finger and reported in units of mmHg.
Heart Rate (beats/min)
Time frame: 3 hours
Heart rate will be measured with a three-lead electrocardiogram (ECG) and reported in units of beats/min.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Aged 35-49 or 50-70 years of age who experienced premature (\<40) or early (≤45) menopause
- Premenopausal 35-49 years of age
- Typical-age menopause (i.e., after 45 years of age), who are between 50-70 years old
- Menopause will be confirmed by subject report of amenorrhea for 12 months and serum FSH of \>30 mIU/mL
Exclusion criteria
- Current nicotine/tobacco use within the past six months
- Are diabetic or asthmatic
- Have diagnosed significant carotid stenosis
- Have a history of significant autonomic dysfunction, heart disease, respiratory disease or a severe neurologic condition such as stroke or traumatic brain injury.
- Have existing metabolic or endocrine abnormities
- Take any heart/blood pressure medications that are determined to interfere with study outcomes
- IF the participant is premenopausal AND currently taking OC or other exogenous steroids that are determined to interfere with study outcomes
- Females who classify as having early or premature menopause AND are not willing to discontinue OC or MHT in order to complete the study
- Are pregnant or breastfeeding
Where
- Minneapolis, Minnesota
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jan 8, 2026 · Source of record for eligibility and locations