The Influence of Estrogen on the Thermoregulatory Responses to Heat Stress in Pre and Postmenopausal Women
试验速览
- 阶段
- 4 期
- 状态
- 招募中
- 入组人数
- 24
- 试验地点
- 1
- 主要终点
- Skin Blood Flow
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
盲法说明
Double (participant, investigator)
入排标准
- 年龄范围
- 42 Years 至 64 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Women ages 42-64
排除标准
- •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
研究组 & 干预措施
Premenopausal estrogen suppression
Participants take a cellulose placebo tablet for 4 days prior to baseline testing and continue until experimental visits are complete. Following completion of placebo testing, participants begin taking 400 mg/day Elagolix for 4 days prior to testing and continue until experimental visits are complete.
干预措施: Elagolix Oral Tablet (Drug)
Premenopausal estrogen suppression
Participants take a cellulose placebo tablet for 4 days prior to baseline testing and continue until experimental visits are complete. Following completion of placebo testing, participants begin taking 400 mg/day Elagolix for 4 days prior to testing and continue until experimental visits are complete.
干预措施: cellulose placebo (Other)
Postmenopausal estrogen supplementation
Participants wear a transdermal estradiol patch or placebo patch for 5 days prior to testing and continue until experimental visits are complete. After 48 hr washout, participants then wear the alternative treatment for 5 days prior to testing until experimental visits are complete.
干预措施: placebo patch (Other)
Postmenopausal estrogen supplementation
Participants wear a transdermal estradiol patch or placebo patch for 5 days prior to testing and continue until experimental visits are complete. After 48 hr washout, participants then wear the alternative treatment for 5 days prior to testing until experimental visits are complete.
干预措施: Estradiol patch (Drug)
结局指标
主要结局
Skin Blood Flow
时间窗: Monitored continuously during both 3 hour passive heating experiments (Visit 1 and Visit 3 approx 3 weeks)
Skin blood flow response to whole body heating is continuously monitored
Local Sweat Rate
时间窗: Monitored continuously during both 3 hour passive heating experiments (Visit 1 and Visit 3 approx 3 weeks)
A small sweat capsule is placed on the forearm for the duration of whole body heating.
Core Temperature
时间窗: Monitored continuously during all 3 hour experimental visits (6 total average of 3 weeks)
Changes in body temperature are measured through a telemetry pill swallowed before each experiment.
次要结局
- Body Mass(Baseline and following 3 hr experimental visit (6 total visits for study completion, an average of 3 weeks))
- Skin Temperature(Calculated continuously for the duration of each 3 hr experimental visit (6 total visits for study completion, an average of 3 weeks))
研究者
W. Larry Kenney
Professor
Penn State University