Muscle Lipid and Insulin Resistance in the Elderly (MIRA)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified March 2009 by University of Pittsburgh.
Recruitment status was  Recruiting
Sponsor:
Information provided by:
University of Pittsburgh
ClinicalTrials.gov Identifier:
NCT00765505
First received: October 2, 2008
Last updated: March 25, 2009
Last verified: March 2009

October 2, 2008
March 25, 2009
July 2004
October 2009   (final data collection date for primary outcome measure)
Insulin sensitivity and muscle fat content will be measured at the beginning and the end of the intervention to determine the effects of exercise on these measures. [ Time Frame: 16 weeks ] [ Designated as safety issue: No ]
Same as current
Complete list of historical versions of study NCT00765505 on ClinicalTrials.gov Archive Site
Examine if exercise-induced improvements in insulin sensitivity are similar in normal weight and in obese older subjects. [ Time Frame: 16 weeks ] [ Designated as safety issue: No ]
Same as current
Not Provided
Not Provided
 
Muscle Lipid and Insulin Resistance in the Elderly
Muscle Lipid and Insulin Resistance in the Elderly

This project will provide novel information concerning the ability of exercise to enhance the capacity for oxidative metabolism of fatty acids and improve insulin resistance in older adults who are at high risk for the development of type 2 diabetes. Ultimately this may help identify mechanisms and therapeutic targets implicated in skeletal muscle metabolic dysregulation. The proposed study is to conduct a randomized controlled exercise training intervention trial in older men and women. In addition, the response to exercise in these subjects will be compared to those of highly endurance-trained, age-matched athletes.

Hypothesis and Specific Aims:

  1. To determine whether aerobic exercise improves both skeletal muscle fat distribution and insulin sensitivity of older men and women. We will test two hypotheses.

    i. Physical exercise in older adults will decrease the amount of fat interspersed within muscle, specifically the fat between muscle groups (intermuscular adipose tissue) as well as decrease specific lipid metabolites within muscle cells, compared to controls.

    ii. Exercise-induced improvements in insulin sensitivity of older men and women will be related to the changes in muscle fat content independent of changes in total body fat or visceral abdominal adipose tissue.

  2. To determine whether increased capacity for oxidative fatty acid metabolism within muscle results in improved insulin sensitivity in older adults. We will test two hypotheses.

    i. Exercise training will increase the capacity of muscle to oxidize fatty acids assessed both in vitro and in vivo.

    ii. Improved capacity for oxidative fatty acid metabolism will predict improvements in insulin sensitivity.

Interventional
Not Provided
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
Obesity
  • Behavioral: Exercise Group
    Sixteen week intervention where subjects will be progressed to four days per week for 45 minutes per session, 180 minutes minimum per week, of moderate intensity supervised exercise.
  • Behavioral: Health Education Group
    Sixteen week intervention. This group will not receive specific exercise education or prescription but will be asked to participate in biweekly health education sessions
  • Experimental: 1
    Exercise Group
    Intervention: Behavioral: Exercise Group
  • Experimental: Health Education Group
    Intervention: Behavioral: Health Education Group
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruiting
300
December 2009
October 2009   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • 60 - 70 years of age
  • No weight gain/loss of >10 lbs in 6 months
  • Sedentary (No more than 1 continuous exercise/week) or Highly trained (>5 exercise sessions/week for a duration of one year or more)
  • Non-Smoker
  • BMI 18-38.0
  • Resting blood pressure less than 150mmHg systolic/95 mmHg diastolic
  • Normal glucose tolerance: Fasting glucose < 100 mg/dl or 2 hour glucose from OGTT < 140 mg/dl or impaired glucose tolerance (fasting glucose > 100 mg/dl < 126 mg/dl or 2 hour glucose from OGTT > 140 mg/dl but less than 200 mg/dl
  • Note from PCP/Cardiologist for exercise clearance if positive stress test symptoms were observed from GXT

Exclusion Criteria:

  • Clinically significant CVD including h/o MI
  • Peripheral Vascular Disease
  • Hepatic, renal, muscular/neuromuscular, or active hematologic/oncologic disease
  • Clinically diminished pulse
  • Presence of bruits in lower extremities
  • Previous history of pulmonary emboli
  • Peripheral Neuropathy
  • Currently not engaged in a regular program and have a V)2 max pre-training value > 55 ml/kg-fat free mass-min., indicative of moderate fitness OR currently engaged in regular program and having a V)2 max value < 55 ml/kg-fat free mass-min.
  • Anemia (Hematocrit < 34%)
  • Any contraindications to moderate exercise
  • Inability and/or willingness to comply with the protocol as written
  • Active alcohol or substance abuse (Past 5 years)
  • Total cholesterol > 300 mg/dL
  • Triglyceride > 350 mg/dL
  • ALT > 80, AST > 80, Alk Phos > 240
  • Proteinuria (defined as > 1+ on routine dipstick) hypothyroidism (sTSH>8)
  • Therapeutic Doses of Nicotinic Acid
  • Type 2 Diabetes: Fasting Glucose > 126 mg/dl or 2 hour glucose > 200 mg/dl
  • Oral Glucocorticoids
  • Females currently on hormone replacement therapy (HRT) less than 6 months
  • Claustrophobia
  • Previous difficulty with lidocaine or other local anesthetic
  • Stress test symptoms:

    • Positive ECG (>2mm ST segment depression) without PCP cardiologist permission to participate
    • Signs or symptoms of cardiovascular decomposition (hypotensive response to exercise
    • Onset of angina or angina like symptoms, shortness of breath, change in heart rhythm, signs of poor perfusion (light-headedness), tightness
    • Hypotension
Both
60 Years to 75 Years
Yes
Contact: Jennifer Gabany, CRNP-C, CCRC 412-578-9259 jmg115@pitt.edu
United States
 
NCT00765505
0405764, 5 R01 AG021961
Yes
Bret H. Goodpaster, University of Pittsburgh
University of Pittsburgh
Not Provided
Principal Investigator: Bret H. Goodpaster, PhD University of Pittsburgh
University of Pittsburgh
March 2009

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP