Females, Aging, Metabolism, and Exercise
- Conditions
- Obesity
- Interventions
- Registration Number
- NCT01712230
- Lead Sponsor
- University of Colorado, Denver
- Brief Summary
This study is designed to determine whether a reduction in hormones (such as occurs during menopause) causes a decrease in calories burned during physical activity. This study will also determine whether a reduction in hormones decreases calories burned while sleeping, resting, and eating and whether an exercise intervention can prevent this.
- Detailed Description
Participants will be women who are nearing menopause based on age (42-52 y) but have normal menstrual cycles. Participants will be randomized to receive monthly injections of placebo or a study drug that reduces sex hormones (GnRH agonist) for 24 weeks. Women who receive GnRH agonist will be further randomized to no exercise or a supervised exercise program. Thus, the 3 treatment groups are: placebo, GnRH agonist, GnRH agonist+exercise. The investigators will measure changes in calories burned during physical activity, sleep, rest, and after a meal after 3 and 6 months of hormone suppression using doubly-labeled water and room calorimetry. Other measures include food intake estimated from food records; body composition measured by dual-energy x-ray absorptiometry (DXA); glucose and insulin responses to an oral glucose tolerance test; and markers of inflammation in the blood.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Female
- Target Recruitment
- 47
- Healthy women aged 40 to 60 years
- Are still experiencing regular menstrual cycles.
- They must be willing to be randomized to placebo or GnRHAG therapy for 24 weeks
- Be physically able to be randomized to participate in a programmed exercise training program.
The investigators will consent up to 132 subjects with the aim of enrolling 22 in each of the 3 groups (placebo, GnRHAG, or GnRHAG+Exercise).
- irregular menstrual cycles defined as 2 or more missed cycles in the previous year
- serum FSH >25 mIU/mL measured during the first 5 days of the menstrual cycle
- on hormonal contraceptive or menopausal therapy
- positive pregnancy test
- intention to become pregnant or start hormonal contraceptive therapy during the period of study
- lactation
- known hypersensitivity to GnRH or leuprolide acetate
- score >16 on the CESD((Center for Epidemiologic Studies Depression Scale )
- severe osteopenia or osteoporosis (i.e., proximal femur or lumbar spine t scores < -2.0)
- abnormal vaginal bleeding
- thyroid dysfunction, defined as an ultrasensitive TSH <0.5 or >5.0 mU/L; volunteers with abnormal TSH values will be re-considered for participation in the study after follow-up evaluation by the PCP with initiation or adjustment of thyroid hormone replacement
- uncontrolled hypertension defined as resting systolic BP >150 mmHg or diastolic BP>90 mmHg; participants who do not meet these criteria at first screening will be re-evaluated, including after follow-up evaluation by the PCP with initiation or adjustment of anti-hypertensive medications
- cardiovascular disease; subjective or objective indicators of ischemic heart disease (e.g., angina, ST segment depression) or serious arrhythmias at rest or during the graded exercise test (GXT) without follow-up evaluation; follow-up evaluation must include diagnostic testing (e.g., thallium stress test) with interpretation by a cardiologist
- orthopedic or other problems that would interfere with participation in the exercise program
- exercising at least 30 minutes per day at a moderate to vigorous intensity most days of the week (defined as >4 d/wk) over the past 6 months
- BMI <40 kg/m2
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Placebo Placebo Monthly placebo injections for 6 months GnRH agonist + exercise Supervised cardiovascular exercise Monthly GnRH agonist injections for 6 months plus supervised cardiovascular exercise intervention GnRH agonist GnRH agonist Monthly GnRH agonist injections for 6 months GnRH agonist + exercise GnRH agonist Monthly GnRH agonist injections for 6 months plus supervised cardiovascular exercise intervention
- Primary Outcome Measures
Name Time Method Change in Physical Activity Energy Expenditure (PAEE) Change from baseline to 6 months PAEE will be calculated as: TEE - REE - TEF, where TEE is total energy expenditure (measured by doubly-labeled water), REE is resting energy expenditure (measured by indirect calorimetry), and TEF is the thermic effect of feeding (estimated using a constant).
- Secondary Outcome Measures
Name Time Method Total Fat Mass Change over 6 months Total Fat mass as measured by DXA
Total Fat Free Mass Change over 6 months Total Fat Free Mass as measured by DXA
Trial Locations
- Locations (1)
University of Colorado - Anschutz Medical Campus
🇺🇸Aurora, Colorado, United States