Race, Menopause and Metabolism After Exercise and Diet
Condition: Obesity; Insulin Resistance; Sedentary Lifestyle
MeSH terms: Insulin Resistance
Study type: Interventional

Summary: 
      The purpose of this study is to test the hypotheses that there are ethnic and genetic
      differences in the mechanisms and magnitude by which hypocaloric weight loss and aerobic
      exercise affect body composition, glucose, lipid, muscle and adipose tissue metabolism in
      overweight, insulin resistant postmenopausal women. This will be tested in a trial comparing
      the effects of weight loss vs. aerobic exercise plus weight loss on glucose, lipid, fat and
      muscle metabolism in overweight African American and Caucasian postmenopausal women.
    

Detailed description: 
      The findings of this study will also determine whether there are racial differences in the
      whole body and cellular mechanisms by which aerobic exercise training and weight loss affect
      glucose, lipid, fat and muscle metabolism in African-American vs. Caucasian postmenopausal
      women. The results also may provide a rationale for targeting specific populations of women
      who might improve glucose, lipid, fat and muscle metabolism more from the addition of
      exercise to dietary restriction than weight loss alone to reduce their risk for type 2
      diabetes and cardiovascular disease.

      The study protocol consists of the following phases:

      Phase 1-Recruitment and screening.

      Phase 2-Weight and dietary stabilization for 4-6 weeks, where participants are taught the
      principles of the American Heart Association "Heart Healthy" diet and provided food to
      consume prior to testing.

      Phase 3-Participants will undergo research testing including glucose clamp and fat biopsy.

      Phase 4-Participants select either weight loss only, or exercise plus weight loss. The
      behavior diet modification weight loss sessions are held by a registered dietitian for 1 hour
      once a week for 6-9 months where the recommended caloric intake for each participant is
      adjusted by the dietitian to elicit a weight loss of approximately 0.2-0.4 kg per week. In
      addition to the weight loss sessions, participants who select the aerobic exercise plus
      weight loss intervention will exercise at the Baltimore Geriatric Research Education and
      Clinical Center (GRECC) exercise facility 3 times a week for 6-9 months using treadmills and
      other aerobic exercise equipment. Exercise sessions begin at low levels of VO2max (maximal
      oxygen consumption) and progress in duration and intensity until the participant is able to
      exercise at more than 75% VO2max for 45 minutes.

      Phase 5-Following the 6-9 months of long-term weight loss or exercise plus weight loss, all
      participants will undergo long-term metabolic testing.
    

Intervention name(s): Diet modification; Aerobic exercise
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Weight loss sessions are held by a registered dietitian for 1 hour once a week for 6-9 months; recommended caloric intake to elicit a weight loss of approximately 0.2-0.4 kg per week; Treadmills and other aerobic exercise equipment 3 times a week for 6-9 months, beginning at low levels of VO2max and progressing in duration and intensity to more than 75% VO2max for 45 minutes
Other intervention name(s): American Heart Association "Heart Healthy" diet
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Exercise; Obesity; Insulin Sensitivity