Influence of Hormone Replacement on Neural Cardiovascular Control in Postmenopausal Women
试验速览
- 阶段
- 不适用
- 状态
- 终止
- 入组人数
- 4
- 试验地点
- 1
- 主要终点
- Change in Exercise Pressor Reflex Responsiveness (Mean Blood Pressure Response (mmHg) and Muscle Sympathetic Nerve Activity Response (Burst Frequency) During Post Handgrip Ischemia.)
研究概览
简要总结
Older women have an exaggerated increase in blood pressure during exercise. However, the reasons for this are unclear. It is important to investigate this phenomenon because a greater blood pressure response to exercise has been associated with an increased risk of stroke and mortality in otherwise healthy individuals. A unique aspect of aging in women is the profound change in hormone levels (i.e. estrogen and progesterone) associated with menopause. The influence of changes in estrogen and progesterone levels on the cardiovascular responses to exercise is poorly understood. However, it has been suggested that these hormones might change the responsiveness of the cardiovascular system. Possible mechanisms that could account for these changes are the arterial baroreflex and feedback from the exercising muscle (known as the exercise pressor reflex), both of which are known to powerfully modulate blood pressure during exercise. However, to date, few human studies have thoroughly examined the influence of changes in hormone levels on baroreflex function during exercise or the exercise pressor reflex in older women. As such, the purpose of this research project is to assess baroreflex function and the exercise pressor reflex in older women after transdermal estrogen and placebo.
详细描述
Study Design Older postmenopausal women will be randomized, in a double-blinded crossover design, to receive (i) transdermal estradiol, delivery rate 100 µg day-1 plus oral placebo, or (ii) placebo patch plus oral placebo. The experimental measurements and procedures below will be performed before and 4 weeks after each treatment.
Experimental measurements:
Blood Pressure- A blood pressure cuff will be wrapped around the right arm to obtain blood pressure via a standard automated auscultometric device (Welch-Allyn). In addition, beat-by-beat blood pressure will be obtained via finger photoplethysmography (Finapress blood pressure monitor).
Heart Rate- Standard limb lead electrodes will be used to obtain heart rate measurements.
Respiration- An elastic band will be placed around the subject's abdomen to measure rate and depth of breathing.
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
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •We plan to study female subjects of all ethnic backgrounds ranging in age from 18 to 80 years. Only healthy, normotensive individuals not taking medications will be included in this study.
- •All postmenopausal women will be at least 4 years post menopause to avoid the potential for perimenopausal interference with study results
排除标准
- •Active cardiopulmonary disease
- •Hypertension
- •Chronic Obstructive Pulmonary Disease with concurrent daily use of inhalers.
- •Known liver disease
- •Peripheral neuropathy
- •Chronic Kidney disease
- •Pregnant women
- •Any of the following contraindications to estrogen usage will cause exclusion:
- •Personal or 1st degree relative (mother, sister, daughter) history of breast, ovarian, or uterine cancer
- •Vaginal bleeding;
- •Current thrombophlebitis or venous thromboembolic disorders including deep vein thrombosis or pulmonary embolus;
- •Arterial thromboembolic disease such as stroke or myocardial infarction
- •Migraine headaches
- •Any previous intolerance to estrogen supplementation.
- •Women who have smoked during the one-year period prior to enrollment.
研究组 & 干预措施
Transdermal estradiol
Transdermal estradiol, delivery rate 100 µg day-1
干预措施: Transdermal estradiol (Drug)
Placebo
placebo patch.
干预措施: Placebo (Drug)
结局指标
主要结局
Change in Exercise Pressor Reflex Responsiveness (Mean Blood Pressure Response (mmHg) and Muscle Sympathetic Nerve Activity Response (Burst Frequency) During Post Handgrip Ischemia.)
时间窗: Within one week prior to and then after one month of transdermal estrogen alone, transdermal estrogen plus progesterone, progesterone alone and placebo.
To estimate exercise pressor reflex responsiveness changes in blood pressure and muscle sympathetic nerve activity from rest to during a period of post handgrip ischemia will be used.
Change in Carotid Baroreflex Sensitivity (Bpm/mmHg)
时间窗: Within one week prior to and then after one month of transdermal estrogen alone, transdermal estrogen plus progesterone, progesterone alone and placebo.
Carotid baroreflex sensitivity will be measured using the application of neck pressure and neck suction. Briefly, a variable neck pressure collar will be placed around the anterior two thirds of the neck to change carotid sinus transmural pressure.
次要结局
未报告次要终点