Clinical trial NCT06798571: Role of Menopause in Thermoregulation
Official title: The Influence of Estrogen on the Thermoregulatory Responses to Heat Stress in Pre and Postmenopausal Women
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE4
Conditions: Menopause
Aging
Keywords: Thermoregulation
Heat Stress
Lead sponsor: Penn State University
Sponsor class: OTHER
First posted: 2025-01-29
Enrollment: 24
Sex: FEMALE
Minimum age (years): 42
Maximum age (years): 64
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Subjects participate in 6 experiments, 3 for each treatment (Elagolix OR Estradiol and placebo). The order of treatment is random.
Primary purpose: BASIC_SCIENCE

Brief summary: The frequency and severity of heat waves has increased in the last decades. Older adults (over 65 years) have impaired responses to heat stress making them at increased risk for adverse events. Previous heat waves report that women over 65 experience worse health outcomes than any other age group and age matched men.

Aging and reproductive hormones, specifically estrogen, independently alter responses to heat stress. However, the combined effects of low estrogen following menopause and aging on the response to heat stress are unknown. In this study, the investigators will identify the role of estrogen in pre and post menopausal women on thermoregulatory responses to heat stress.

Detailed description: Premenopausal and postmenopausal women will be recruited and different interventions will be given to each group. To mimic a postmenopausal hormone profile, premenopausal women will be given a GnRH antagonist, which acutely reduces estrogen concentrations. This induces a temporary post-menopausal state without compounding aging effects. Postmenopausal women will be given a transdermal estradiol patch to acutely raise estrogen concentrations. Supplementing estrogen in postmenopausal women allows for the effect of menopausal low estrogen concentration to be removed from the physiological effects of aging.

Subjects sign an informed consent form and undergo a medical screening prior to participation. The screening includes a physical exam, anthropometry, chemical and lipid profiles.

Each subject will complete 6 (3 for each treatment) experimental trials. For each intervention, participants will complete one passive heating experiment first, followed by two active heating experiments.

Eligibility criteria: Inclusion Criteria:

* Women ages 42-64

Exclusion Criteria:

* Chron's disease, diverticulitis, or similar gastrointestinal disease
* Abnormal resting exercise electrocardiogram (ECG)
* Tobacco use
* High-risk determined by the Atherosclerotic Cardiovascular Disease (CVD) Risk Factor
* Assessment
* Using hormone therapy
* Using hormonal contraceptives

Primary outcomes:
measure: Skin Blood Flow
timeFrame: Monitored continuously during both 3 hour passive heating experiments (Visit 1 and Visit 3 approx 3 weeks)
measure: Local Sweat Rate
timeFrame: Monitored continuously during both 3 hour passive heating experiments (Visit 1 and Visit 3 approx 3 weeks)
measure: Core Temperature
timeFrame: Monitored continuously during all 3 hour experimental visits (6 total average of 3 weeks)
Secondary outcomes:
measure: Body Mass
timeFrame: Baseline and following 3 hr experimental visit (6 total visits for study completion, an average of 3 weeks)
measure: Skin Temperature
timeFrame: Calculated continuously for the duration of each 3 hr experimental visit (6 total visits for study completion, an average of 3 weeks)
Other outcomes:
Locations:
city: University Park
country: United States
facility: Noll Laboratory
state: Pennsylvania
Study officials:
affiliation: The Pennsylvania State University
name: W. Larry Kenney, Ph.D.
role: PRINCIPAL_INVESTIGATOR
References: