The Anabolic Effects of Estrogen on Skeletal Muscles

Study Overview
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Brief Summary
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Purpose: to study the effect of estrogen replacement on muscle hypertrophy in response to 12 weeks resistance training in postmenopausal women Hypothesis: Transdermal administration of 17-β estradiol enhance the anabolic effect of resistance training on muscle mass, strength in postmenopausal women Primary outcome: Muscle hypertrophy (muscle CSA, muscle fiber type specific CSA) Secondary outcome: Messenger RiboNucleic Acid (mRNA)(real-time PCR), protein (western blotting), satellite cell proliferation and activation, Strength, functional test, muscle protein synthese. Design: Two groups of healthy postmenopausal women (½-5 years after menopause) who have not performed regular resistance exercise (<1 times per week) the last two years. Randomized, controlled intervention study +/- transdermal administration of estrogen (17-β estradiol). Both groups perform 12 weeks of supervised progressive resistance training (3/week) aiming to induce muscle hypertrophy in the legs.

Official Title
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The Anabolic Effects of Estrogen on Skeletal Muscles

Conditions
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Estrogen Supplementation

Intervention / Treatment
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* Other: Exercise + Estrogen
* Other: Exercise + Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Postmenopausal women, more than 6 months, but less than 5 years since last menstruation. Exclusion Criteria: Less than 2 hours exercise with moderate to high intensity per week the last year, no regular resistance exercise the last 2 years (less than 5 exercise bouts during the last year) No previous or present lower limb injuries which may hinder participation in strength training No use of medicine which may influence the adaptation to strength training such as regular use of nonsteroidal anti-inflammatory drugs and use of statins, no muscle Joint or metabolic diseases or other chronic diseases that would affect the results of the investigation, high blood pressure (>140/90), smoking

Ages Eligible for Study
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Minimum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exercise + Estrogen<br>Strength training 3 times a week for 12 weeks. Estrogen patches which provide 100 um pr. 24 hours. | Other: Exercise + Estrogen<br>* 12 weeks resistance training and estrogen patches<br>|
| Active Comparator: Exercise + Placebo<br>Strength training 3 times a week for 12 weeks. Placebo patches. | Other: Exercise + Placebo<br>* 12 weeks resistance training and placebo patches<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle hypertrophy | muscle cross sectional area measured by Magnetic resonance imaging (MR) -scans | 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle fiber hypertrophy | Histology analysis of muscle fiber area | 12 weeks | 
| Muscle strength | Maximal isometric muscle strength | 12 weeks | 
| tendon size | Tendon cross sectional area measured by MR-scan | 12 weeks | 
| Fat cell size | Analysis of fat cell size (diameter) | 12 weeks | 
| Fat mass | Dual-energy X-ray absorptiometry (DXA) scan of total fat mass | 12 weeks | 
| Fat free mass | Fat free mass measured by DXA scan | 12 weeks |