Investigating how sex affects recovery from muscle disuse

Sex-specific Determinants of Early-phase Recovery From Skeletal Muscle Disuse

Not applicable Interventional The University of Texas Health Science Center at San Antonio · NCT04151901

This study tests how being male or female affects recovery from muscle loss after not using one leg for a week, focusing on healthy middle-aged adults.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment80 (estimated)
Ages50 Years to 65 Years
SexAll
SponsorThe University of Texas Health Science Center at San Antonio Academic / other
Locations2 sites (Galveston, Texas and 1 other locations)
Trial IDNCT04151901 on ClinicalTrials.gov

What this trial studies

This project involves a two-phase randomized clinical trial where participants undergo 7 days of unilateral leg disuse followed by 1 week of bilateral leg rehabilitation. The study aims to explore sex-specific effects of muscle disuse and identify molecular determinants of susceptibility to muscle atrophy. It will also map the early molecular responses to rehabilitation in both men and post-menopausal women. The trial focuses on healthy middle-aged individuals to better understand the risks associated with muscle disuse and recovery.

Who should consider this trial

Good fit: Ideal candidates are healthy middle-aged men and post-menopausal women aged 50-65 years.

Not a fit: Patients with significant musculoskeletal issues or those on hormone replacement therapy may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to tailored rehabilitation strategies that improve recovery outcomes for individuals at risk of muscle disuse.

How similar studies have performed: While there is existing research on muscle disuse and recovery, this study's focus on sex-specific determinants is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. All races and ethnic backgrounds
2. Men and women, age 50-65 years
3. Generally healthy (see exclusion criteria)
4. Able and willing to provide informed consent
5. Ability to speak and read English
6. Post-menopausal women (no menses within the last 12 months)
7. Body mass index: 18.5-35 kg/m2 or BMI\>35 if thigh adiposity does not impair muscle biopsy

Exclusion Criteria:

1. Compromised musculoskeletal function that precludes safe participation or use of crutches
2. Pre-menopausal women
3. Hypogonadal men (testosterone \<300 ng/dL)
4. Women taking hormone replacement therapy (HRT)
5. Sarcopenia (European Working Group on Sarcopenia in Older People, EWGSOP102)
6. Clinically significant heart disease (e.g. New York Heart Classification greater than grade II; ischemia)
7. Peripheral vascular disease
8. History of claudication
9. Pulmonary disease
10. History of systemic or pulmonary embolus
11. Uncontrolled blood pressure (systolic BP\>170, diastolic BP\>95 mmHg)
12. Impaired renal function (creatinine \>1.5 mg/dl)
13. Anemia (hematocrit \<33)
14. Untreated thyroid disease (abnormal TSH)
15. A recent history (\<12 months) of GI bleed
16. Diabetes mellitus or other untreated endocrine or metabolic disease
17. Electrolyte abnormalities
18. Any history of stroke, hypo- or hyper-coagulation disorders
19. Employment requiring long (\>1 h) uninterrupted period of standing
20. Inability to meet study travel requirements (e.g. manual geared car)
21. Recent history of balance issues or falls.
22. Recent (3 years) treated cancer other than basal cell carcinoma
23. Systemic steroids, anabolic steroids, growth hormone or immunosuppressant use within 12 months
24. Recent (2 months) adherence to a weight-loss or weight-gain diet
25. Weight change of 5% or more in previous 6 months
26. Body mass index \>30 or excess body fat that compromises muscle biopsy collection
27. Acute infectious disease or chronic infection
28. Alcohol or drug abuse
29. Any other condition or event considered exclusionary by study physician

Where this trial is running

Galveston, Texas and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Atrophy of Muscle Due to DisuseRehabilitation
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.