Effects of Estrogen Deficiency on Energy Expenditure

Not Applicable

Completed

• Conditions: Obesity
• Interventions: Drug: Estrogen suppression

• Registration Number: NCT01846728
• Lead Sponsor: University of Colorado, Denver

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.

Study Timeline

• Study Start: 2013-04
• Study First Submitted: 2013-04-30
• Study First Submitted QC: 2013-04-30
• Study First Posted: 2013-05-03
• Primary Completion: 2015-10
• Study Completion: 2016-10
• Status Verified: 2019-10
• Results First Submitted: 2019-10-04
• Results First Submitted QC: 2019-10-28
• Last Update Submitted: 2019-10-28
• Results First Posted: 2019-11-18
• Last Update Posted: 2019-11-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 6

Inclusion Criteria

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

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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

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Estrogen suppression	Estrogen suppression	Estrogen production will be suppressed using Lupron, a drug that blocks normal production of ovarian hormones

Primary Outcome Measures

Name	Time	Method
Brown Adipose Tissue Activity	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).

Secondary Outcome Measures

Name	Time	Method
Cold Induced Thermogenesis	Baseline and after 3 months of suppression	The increase in energy expenditure above resting during cold exposure
Fat Mass	Baseline and after 3 months of suppression	Amount of body fat (in kg)
Fat Free Mass	Baseline and after 3 mo of suppression	Fat free mass measured by DXA
Resting Energy Expenditure	after 3 months of suppression	Energy expenditure measured in the resting state

Trial Locations

Locations (1)

University of Colorado Anschutz Medical Campus; 🇺🇸 Aurora, Colorado, United States