OAIC Supported Studies
Optimizing Body Composition for Function in Older Adults (OPTIMA)
Contact: | Phone: |
Stephen Kritchevsky, PhD | 336-713-8548 |
Based on data from the CDC’s 2003 Behavioral Risk Factor Surveillance System survey, 59.7% and 20.3% of adults 65 years of age and older were either overweight (BMI ≥ 27) or obese (BMI > 30), respectively.1 In older adults obesity is associated with a number of adverse health consequences including type II diabetes, osteoarthritis of the knee, atherosclerosis and increased rates of functional decline.2 Weight loss interventions in older adults have been shown to improve cardiovascular risk factors, pulmonary function, inflammatory and glycemic status.3-6 Despite these benefits there has been reluctance to recommend hypocaloric diets to older adults.2 The reluctance stems, in part, from the view that weight loss alone might exacerbate age-related losses in skeletal muscle. The hypothetically ideal weight loss program for older adults would target the loss of total body fat, and visceral and inter-muscular fat in particular, while sparing skeletal muscle mass. In theory, such a program would maximize metabolic benefits while minimizing functional risk.
The purpose of this pilot study is to compare two strategies intended to improve the health of overweight older adults by improving body composition. One strategy, resistance training, is designed to preserve skeletal muscle mass. The other strategy, the use of a PPAR-γ agonist, is designed to enhance the loss of fat from visceral and skeletal depots. These strategies will be used in conjunction with a hypocaloric diet and will be compared to a hypocaloric diet alone to determine if either of these strategies are superior in reducing visceral fat and preserving muscle mass.
The proposed pilot study is designed to provide critical information that will support a larger randomized trial designed to test whether differing strategies to affect body composition lead to differential functional outcomes. The pilot itself has sufficient statistical power to test whether or not the proposed optimizing strategies will have the desired effects on body composition, but not to test whether these strategies have a differential effect on function. In the absence of a differential effect on body composition, it would be unlikely that there would be a differential effect on function. Thus, primary outcomes of the pilot relate to evaluating the effects of the two strategies on body composition end-points, and the secondary outcomes of the pilot are collected in order to provide information on the variability and measurement characteristics of what will be the primary focus of the main trial. Since data from Health ABC supports the idea that the changes in body composition differ in men versus women undergoing weight change involuntarily, the pilot has been designed to be of sufficient size to examine the main effect of the two intervention strategies in men and women separately.
