Clinical trial NCT01846728: Effects of Estrogen Deficiency on Energy Expenditure
Official title: Ovarian Function and Facultative Thermogenesis
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Lead sponsor: University of Colorado, Denver
Sponsor class: OTHER
Collaborators: name: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
First posted: 2013-05-03
Enrollment: 6
Sex: FEMALE
Minimum age (years): 20
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: OTHER

Brief summary: 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.

Detailed description: 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.

Eligibility criteria: Inclusion Criteria:

* Body mass index \< 30 kg/m2
* Normal menstrual cycles
* Premenopausal

Exclusion Criteria:

* 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

Primary outcomes:
measure: Brown Adipose Tissue Activity
timeFrame: Baseline and after 3 months of suppression
Secondary outcomes:
measure: Cold Induced Thermogenesis
timeFrame: Baseline and after 3 months of suppression
measure: Fat Mass
timeFrame: Baseline and after 3 months of suppression
measure: Fat Free Mass
timeFrame: Baseline and after 3 mo of suppression
measure: Resting Energy Expenditure
timeFrame: after 3 months of suppression
Other outcomes:
Locations:
city: Aurora
country: United States
facility: University of Colorado Anschutz Medical Campus
state: Colorado
Study officials:
affiliation: University of Colorado, Denver
name: Edward Melanson, PhD
role: PRINCIPAL_INVESTIGATOR
References: