Menopause Transition, Sex Hormone Deficiency and Autonomic and Vascular Function
NCT Number: NCT06490146
Status: NOT_YET_RECRUITING
Study Type: OBSERVATIONAL
Conditions: Menopause
Interventions: OTHER: No intervention
Sponsor: University of Minnesota
Sex: FEMALE
Age: ADULT
Enrollment: 80
Study Design: Observational Model: |Time Perspective: p
Start Date: 2024-09-15
Completion Date: 2030-01-31

Summary:
This is a longitudinal study to determine the influence of the menopause transition on autonomic and vascular function. PI Keller-Ross has published data demonstrating that postmenopausal females have greater sympathetic neural reactivity during a stressor compared with age-matched males and younger females and males. A paucity of literature exists, however, on the role of the menopause transition in autonomic function because the majority of experimental studies on menopause physiology are cross-sectional and/or focused on older, postmenopausal females .

The influence of age on HTN is robust, whereas the effects of menopause are still unclear. Preliminary data demonstrate a clear association between age and sympathetic activity in females; how the transition through menopause influences these relations, however, remains unknown. The study will enroll 80 midlife (45-55 years of age) females to measure longitudinally the trajectory of autonomic and vascular function during the transition through menopause. The study hypothesizes that through the menopause transition, an increase in sympathetic activity and an impaired baroreflex sensitivity and endothelial function will emerge.

Primary Outcome Measures: MSNA- Burst frequency, measured in bursts/min

Microneurography to measure MSNA: Microneurography is a direct measurement of electrical activity of peripheral sympathetic nerves. A tungsten microelectrode is placed in a peripheral nerve (Figure 8) to record real-time activity from efferent sympathetic vasoconstrictor nerve fibers. MSNA is the gold-standard measure for sympathetic activity

Participants attend experimental visits annually until they enter perimenopause, at which point they will attend such visits every six months., up to 12 months|MSNA- Burst incidence, measured in bursts/100 heartbeats

Microneurography to measure MSNA: Microneurography is a direct measurement of electrical activity of peripheral sympathetic nerves. A tungsten microelectrode is placed in a peripheral nerve (Figure 8) to record real-time activity from efferent sympathetic vasoconstrictor nerve fibers. MSNA is the gold-standard measure for sympathetic activity

Participants attend experimental visits annually until they enter perimenopause, at which point they will attend such visits every six months., up to 12 months|MSNA- total activity, Microneurography to measure MSNA: Microneurography is a direct measurement of electrical activity of peripheral sympathetic nerves. A tungsten microelectrode is placed in a peripheral nerve (Figure 8) to record real-time activity from efferent sympathetic vasoconstrictor nerve fibers. MSNA is the gold-standard measure for sympathetic activity

Participants attend experimental visits annually until they enter perimenopause, at which point they will attend such visits every six months., up to 12 months
Secondary Outcome Measures: cardiovagal baroreflex sensitivity: ms/mmHg, Cardiovagal baroreflex is estimated by responses in the R-R interval of the ECG to changes in systolic pressure.

Participants attend experimental visits annually until they enter perimenopause, at which point they will attend such visits every six months., up to 12 months|sympathetic baroreflex sensitivity: bursts/100heartbeats/mmHg, Sympathetic baroreflex is estimated by responses in MSNA to changes in diastolic pressure.

Participants attend experimental visits annually until they enter perimenopause, at which point they will attend such visits every six months., up to 12 months|vascular conductance (mL/100mL tissue/min/mmHg), vascular conductance via venous occlusion plethysmography will be quantified by FBF/mean arterial pressure

Participants attend experimental visits annually until they enter perimenopause, at which point they will attend such visits every six months., up to 12 months