About this trial

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.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

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

Disqualifiers

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.

Trial population

Two scenarios of recruiting and enrolling premature/early menopausal females have been determined. 1) Enroll participants prior to starting MHT and/or 2) for patients already taking prescribed MHT, a standard protocol has been developed with Dr. Torkelson on guidelines for enrolling these participants. This includes a baseline estradiol (E2) blood draw, then in coordination with the participant and their physician, the participant will stop taking MHT. Estradiol will be tested every two weeks, up to 3 times (6 weeks). When estradiol is \<30 pg/ml for two weeks, participants will be enrolled in the study and can commence MHT immediately upon completion of study visit.

Trial design

Design model

Cohort

Time perspective

Prospective

Treatments tested in this trial

Microneurography to measure muscle sympathetic nerve activity (MSNA)
Diagnostic test
Microneurography is a direct measurement of electrical activity of peripheral sympathetic nerves
Baroreflex sensitivity testing
Diagnostic test
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.
Sympathoexcitatory Maneuvers
Diagnostic test
Cold Pressor Test (CPT) and Upper extremity fatiguing contraction with post exercise circulatory occlusion (PECO) will be performed
Blood tests
Diagnostic test
Serum FSH, estrogen, progesterone, and testosterone will be measured

Treatment groups

160 Participants

are divided into 4 treatment groups

Group A: Aim 1: Postmenopausal Women4 interventions

Group B: Aim 1: Premenopausal Women4 interventions

Group C: Aim 2: Premature/Early Menopause4 interventions

Group D: Aim 2: Typical-Age Menopause4 interventions

Trial outcomes

Primary outcomes

1

Muscle Sympathetic Nerve Activity (MSNA) (bursts per minute)

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.

Time frame

3 hours

2

Muscle Sympathetic Nerve Activity (MSNA) (bursts/100 heart beats)

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.

Time frame

3 hours

3

Cardiac baroreflex sensitivity

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.

Time frame

3 hours

4

Sympathetic baroreflex sensitivity

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.

Time frame

3 hours

Secondary outcomes

1

Respiratory Rate (breaths/min)

Respiratory rate will be measured with a belt placed around the stomach and reported in units of breaths-per-minute.

Time frame

3 hours

2

Heart Rate Variability (frequency)

Heart rate variability will be measured using electrocardiogram and reported in units of Hertz.

Time frame

3 hours

3

Heart Rate Variability (time)

Heart rate variability will be measured using electrocardiogram and reported in units of milliseconds.

Time frame

3 hours

4

Borg Rating of Perceived Exertion

Participants will be asked to rate their perceived exertion using the Borg Rating of Perceived Exertion scale. Scores range from 6-20 with higher scores indicating greater exertion.

Time frame

3 hours

Autonomic Regulation of Blood Pressure in Premature and Early Menopausal Women

About this trial

Eligibility criteria

Qualifiers

Disqualifiers

Trial population

Trial design

Treatments tested in this trial

Treatment groups

Trial outcomes

Primary outcomes

Secondary outcomes

Other outcomes

Sponsors and contacts