Optimizing Body Composition for Function in Older Adults

In this pilot we propose to recruit 88 older (65 - 79 yrs) men (n=48) and women (n=40) at risk for disability and with indications for weight loss according to NIH guidelines. All will be enrolled in a dietary intervention designed to generate a caloric deficit of 500 kcal/day for a 4 month period. All will receive supplemental vitamin D and calcium. These participants will be randomized into one of 4 groups:

Group 1 - Hypocaloric diet (and placebo) Group 2 - Hypocaloric diet and resistance training designed to maximize muscular power (and placebo) Group 3 - Hypocaloric diet and a PPAR- γ agonist (pioglitazone/Actos™) Group 4 - Hypocaloric diet and resistance training and pioglitazone/Actos™

The specific aims of the pilot are:

• In both men and women, to determine whether randomization to resistance exercise is associated with an increased retention of appendicular non-bone lean mass compared to those not undergoing power training.
• In both men and women, to determine whether randomization to the pioglitazone group is associated with an increased loss of visceral adiposity relative to randomization to the non-pioglitazone group.
• Assess the feasibility of the recruitment, assessment and intervention strategies
• To estimate adherence to the weight loss, exercise training, and drug interventions;
• In this population, to determine measurement characteristics of the functional outcomes that will be considered as primary end-points of the larger study.
• To obtain pilot data on a subset of participants to determine the feasibility, acceptability and measurement characteristics of muscle samples (biopsies) to quantify intramyocellular lipid in this study population.

Inclusion criteria

• Weight Stable, Indication for weight loss per NIH guidelines, Performance on the short physical performance battery score 3-10

Exclusion criteria

• Diabetes, weight > 136 kg, Medical condition that limits exercise participation, Congestive heart failure, abnormal kidney function, higher ALT than normal, currently involved in a weight loss or exercise program, current smoking, alcohol or drug abuse, taking anti-inflammatory steroids, taking protein supplements, taking PPAR-gamma agonist, edema, anemia