Physical Inactivity
Conditions
Brief summary
This is an interventional study enrolling older individuals aged 60-85y to observe changes during physical inactivity. This study is investigating the relation between short-term physical inactivity and the impact of muscle health and function. The enrollment goal is 8 participants. The study will occur over the course of a month where participants will undergo testing before and after a reduction in physically activity levels. There will be a screening event collecting baseline data, two body composition scans, muscle function and oral glucose tolerance tests and a metabolic study before and after a 2-week period of inactivity. Each metabolic study will entail three-muscle biopsies: one before and 2 after the ingestion of leucine.
Detailed description
Pre-testing- The baseline evaluation will assess muscle function and strength, and an oral glucose tolerance test. After the baseline visit, participants will be provided with a step activity monitor to track their level of activity. This will provide a baseline of the participant's normal level of physical activity so an accurate level of 75% activity reduction can be determined. A 3-day daily dietary diary will be provided for the participant to self-report prior to the experiment, as well. Day 1- After the participant completes their normal activity log and dietary diary, they will be asked to return to the research center for a body composition scan and a metabolic study. The metabolic study will involve blood sampling from an arm vein and muscle biopsies from the thigh before and after a leucine drink. 2-week period of inactivity- After the metabolic study, the participant will return home and maintain a reduced level of activity (75% reduction) for a two-week period. During this time, the participant will receive phone calls from research personnel in order to maintain adherence to the intervention. Day 14- After the 2-week reduced activity period, the participant will return to the research center to receive a body composition scan and undergo a metabolic study identical to 'Day 1'. Post-testing- After Day 14, the participant will be asked to return once again to the research center for a oral glucose tolerance test and the exercise lab for muscle function testing.
Interventions
Participants will reduce their level of physical activity for 2-weeks as defined as approximately 75% reduction from their baseline level of physical activity.
Sponsors
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
University of Utah
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Participants will be tested before and 2-weeks after they have reduced their level of physical activity
Eligibility
Sex/Gender
ALL
Age
60 Years to 85 Years
Healthy volunteers
Yes
Inclusion criteria
* Age between 60-85 years * Ability to sign informed consent * Free-living, prior to admission
Exclusion criteria
* Cardiac abnormalities considered exclusionary by the study physician (e.g., Chronic heart Failure, right-to-left shunt) * Uncontrolled endocrine or metabolic disease (e.g., hypo/hyperthyroidism, diabetes) * History of kidney disease or failure * 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) * Risk of blood clotting including family history of thrombophilia, pulmonary emboli, myeloproliferative diseases including polycythemia (Hb\>18 g/dL) or thrombocytosis (platelets\>400x103/mL), and connective tissue diseases (positive lupus anticoagulant), hyperhomocystinemia, deficiencies of factor V Leiden, proteins S and C, and antithrombine III * Use of anticoagulant therapy (e.g., Coumadin, heparin) * Elevated systolic pressure \>150 or a diastolic blood pressure \> 100 * Cancer or history of successfully treated cancer (less than 1 year) other than basal cell carcinoma * Implanted electronic devices (e.g., pacemakers, electronic infusion pumps, stimulators) * Currently on a weight-loss diet or body mass index \> 30 kg/m2 * Chronic systemic corticosteroid use (≥ 2 weeks) within 4 weeks of enrollment and for study duration (intra-articular/topical/inhaled therapeutic or physiologic doses of corticosteroids are permitted). Androgens or growth hormone within 6 months of enrollment and for study duration (topical physiologic androgen replacement is permitted) * History of stroke with motor disability * A recent history (\<12 months) of GI bleed * History of liver disease * History of respiratory disease (acute upper respiratory infection, history of chronic lung disease) * Prior history of Heparin-Induced Thrombocytopenia * An HbA1c value at or greater than 6.5% * Any other condition or event considered exclusionary by the PI and faculty physician
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Lean Mass | baseline and 2-weeks | Change in lean mass |
| Strength | baseline and 2-weeks | Change in muscle strength |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Reduced Physical Activity Participants will reduce their physical activity levels for 2-weeks by approximately 75% of their baseline level of physical activity
Reduced Physical Activity: Participants will reduce their level of physical activity for 2-weeks as defined as approximately 75% reduction from their baseline level of physical activity. | 8 |
| Total | 8 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 1 |
Baseline characteristics
| Characteristic | Reduced Physical Activity |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 6 Participants |
| Age, Categorical Between 18 and 65 years | 2 Participants |
| HbA1c | 5.5 % of hemoglobin STANDARD_DEVIATION 0.3 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 8 Participants |
| Region of Enrollment United States | 8 participants |
| Sex: Female, Male Female | 6 Participants |
| Sex: Female, Male Male | 2 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 9 |
| other Total, other adverse events | 0 / 9 |
| serious Total, serious adverse events | 0 / 9 |
Outcome results
Primary
Lean Mass
Change in lean mass
Time frame: baseline and 2-weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Reduced Physical Activity | Lean Mass | 403 grams | Standard Error 142 |
Primary
Strength
Change in muscle strength
Time frame: baseline and 2-weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Reduced Physical Activity | Strength | -8 percentage of leg strength | Standard Error 0.1 |