Nutrient Regulation of Amino Acid Transporters in Aging Human Skeletal Muscle

This study is currently recruiting participants. (see Contacts and Locations)
Verified March 2013 by University of Utah
Sponsor:
Information provided by (Responsible Party):
University of Utah
ClinicalTrials.gov Identifier:
NCT01669590
First received: August 10, 2012
Last updated: March 19, 2013
Last verified: March 2013
  Purpose

The goal of the research project is to determine how aging and inactivity reduce the muscle anabolic effect of nutrients and lead to muscle and functional loss. The central hypothesis is that aging reduces mTORC1 signaling and the expression of skeletal muscle amino acid transporters in response to anabolic stimulation leading to reduced muscle adaptation to increased intracellular amino acid requirements. The investigators further hypothesize that inactivity exacerbates this effect with significant muscle and functional loss, and rehabilitation restores muscle signaling, metabolism and function to baseline values.


Condition
Healthy

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective

Further study details as provided by University of Utah:

Primary Outcome Measures:
  • amino acid transporter [ Time Frame: before and after (1 and 3h) amino acid ingestion. These samples will be taken before bed rest and 7 days after bed rest. ] [ Designated as safety issue: No ]
    Muscle biopsies will be sampled from the vastus laterals before amino acid ingestion and then 1 and 3h after amino acid ingestion. Muscle biopsies will be processed using western blotting and gene expression to assess the expression of specific amino acid transporters. The investigators are interested in the change in expression of amino acid transporters in response to amino acid ingestion from baseline. The response before bed rest will be compared to after bed rest.


Estimated Enrollment: 28
Study Start Date: December 2011
Groups/Cohorts
old (60-75yr)
young (18-35y)

  Eligibility

Ages Eligible for Study:   18 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

young and older healthy humans

Criteria

Inclusion Criteria:

1 . Age between 18-35 and 60-75 yrs 2. Ability to sign informed consent 3. Mini-mental state exam score >26 4. Free-living, prior to admission

Exclusion Criteria:

  1. Cardiac abnormalities considered exclusionary by the study physician (e.g., CHF, CAD, right-to-left shunt)
  2. Uncontrolled endocrine or metabolic disease (e.g., hypo/hyperthyroidism, diabetes)
  3. GFR <65 mL/min/1.73m2 or evidence of kidney disease or failure
  4. Vascular disease or risk factors of peripheral atherosclerosis. (e.g., uncontrolled hypertension, obesity, diabetes, hypercholesterolemia > 250 mg/dl, claudication or evidence of venous or arterial insufficiency upon palpitation of femoral, popliteal and pedal arteries)
  5. Risk of DVT including family history of thrombophilia, DVT, pulmonary emboli, myeloproliferative diseases including polycythemia (Hb>18 g/dL) or thrombocytosis (platelets>400x103/mL), and connective tissue diseases (positive lupus anticoagulant), hyperhomocysteinemia, deficiencies of factor V Leiden, proteins S and C, and antithrombin III
  6. Use of anticoagulant therapy. (e.g., Coumadin, heparin)
  7. Prior history of Heparin-Induced Thrombocytopenia (HIT)
  8. Elevated systolic pressure >150 or a diastolic blood pressure > 100
  9. Implanted electronic devices (e.g., pacemakers, electronic infusion pumps, stimulators)
  10. Cancer or history of successfully treated cancer (less than 1 year) other than basal cell carcinoma
  11. Currently on a weight-loss diet or body mass index > 30 kg/m2
  12. Inability to abstain from smoking for duration of study
  13. A history of > 20 pack per year smoking
  14. HIV or hepatitis B or C*
  15. Recent anabolic or corticosteroids use (within 3 months)
  16. Subjects with hemoglobin or hematocrit lower than accepted lab values
  17. Agitation/aggression disorder (by psychiatric history and exam)
  18. History of stroke with motor disability
  19. A recent history (<12 months) of GI bleed
  20. Pregnancy as determined by a pregnancy test
  21. Depression [>5 on the 15 items Geriatric Depression Scale (GDS)]
  22. Alcohol or drug abuse
  23. Exercise training (>1 session of moderate to high intensity aerobic or resistance exercise/week)
  24. Liver disease (AST/ALT 2 times above the normal limit, hyperbilirubinemia)
  25. Respiratory disease (acute upper respiratory infection, history of chronic lung disease with resting oxygen saturation <97% on room air)
  26. Any other condition or event considered exclusionary by the PI and faculty physician
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01669590

Contacts
Contact: Micah Drummond 801-585-1310 micah.drummond@hsc.utah.edu

Locations
United States, Utah
The University of Utah Recruiting
Salt Lake City, Utah, United States, 84112
Contact: Micah Drummond, PhD         
Principal Investigator: Micah Drummond         
Sponsors and Collaborators
University of Utah
  More Information

No publications provided

Responsible Party: University of Utah
ClinicalTrials.gov Identifier: NCT01669590     History of Changes
Other Study ID Numbers: IRB_00050933
Study First Received: August 10, 2012
Last Updated: March 19, 2013
Health Authority: United States: Institutional Review Board

ClinicalTrials.gov processed this record on August 27, 2014