Ovarian Function and Facultative Thermogenesis
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 6
- 试验地点
- 1
- 主要终点
- Brown Adipose Tissue Activity
研究概览
简要总结
Menopause is associated with weight gain, but the reasons why are not clear. In this study, the investigators will determine if reducing estrogen levels causes a decrease in the ability of the body to produce heat. If so, this would suggest this is one way that menopause may cause weight gain.
详细描述
The purpose of this pilot study is to investigate the role of the female sex hormone estrogen, on metabolism, thermoregulation and energy expenditure. Weight and fat gain increase after the menopause, but reasons for this are not clear. Loss of estrogen may cause changes in how women regulate metabolism and thermoregulation, possibly leading to weight gain. Specifically, this study will determine how loss of estrogen affects facultative thermogenesis. Loosely defined, facultative thermogenesis represents heat production that is turned on when needed. For example, when body core temperature falls below a certain threshold, a shivering response is invoked in skeletal muscle to increase heat production and, thus, energy expenditure. However, exposure over several hours to mild cold temperatures that do not trigger shivering (16-20⁰ C) also induces an increase in energy expenditure (cold-induced non-shivering thermogenesis). Although several different tissues may contribute to this response, the recent identification of functional brown adipose tissue (BAT) in humans has promoted an interest in how BAT is activated in humans and its potential role in regulating energy balance and body weight. The investigators will measure BAT activity using PET/CT scans pre and post three months of estrogen suppression.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Other
- 盲法
- None
入排标准
- 年龄范围
- 20 Years 至 40 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Body mass index < 30 kg/m2
- •Normal menstrual cycles
- •Premenopausal
排除标准
- •irregular menstrual cycles defined as 2 or more missed cycles in the previous year
- •on hormonal contraceptive or menopausal therapy
- •positive pregnancy test
- •intention to become pregnant or start hormonal contraceptive therapy during the period of study
- •lactation
- •severe osteopenia or osteoporosis (i.e., proximal femur or lumbar spine t scores < -2.0)
- •abnormal vaginal bleeding
- •thyroid dysfunction
- •uncontrolled hypertension
- •exercising at least 30 minutes per day at a moderate to vigorous intensity >1 d/wk) over the past 6 months
研究组 & 干预措施
Estrogen suppression
Estrogen production will be suppressed using Lupron, a drug that blocks normal production of ovarian hormones
干预措施: Estrogen suppression (Drug)
结局指标
主要结局
Brown Adipose Tissue Activity
时间窗: Baseline and after 3 months of suppression
Brown adipose tissue activity will be measured using Positron Emission Tomography/computer tomography (PET/CT) before and after 3 months of estrogen suppression. Activity is quantified as the standard uptake value (SUV), It is a mathematically derived ratio that is a semiquantitative measure of the tracer uptake in a region of interest that normalizes the lesion activity to the injected activity and a measure of the volume of distribution (usually total body weight or lean body mass).
次要结局
- Cold Induced Thermogenesis(Baseline and after 3 months of suppression)
- Fat Mass(Baseline and after 3 months of suppression)
- Fat Free Mass(Baseline and after 3 mo of suppression)
- Resting Energy Expenditure(after 3 months of suppression)