Metformin for Preventing Frailty in High-risk Older Adults

Physical frailty is a geriatric syndrome that leads to poor health outcomes such as falls, disability, institutionalization, and death. The prevalence of frailty is estimated to be 7-15% among community-dwelling older U.S. adults. The associated costs of frailty were estimated to be more than $18 billion in 2000 and these will continue to increase over the next two decades. Thus, an increasingly frail older population will have major implications for the demand for health care services, including hospital usage, home care, and long-term care. Data from several studies have suggested strong roles for diabetes and insulin resistance, which are associated with increased inflammation, in the physiological basis of frailty. The investigators' recent epidemiological research with a community-based population of older adults showed that diabetes was the most significant predictor of frailty onset and worsening over time. While the importance of frailty and its impact on an aging U.S. society have been widely recognized, to date there are no effective interventions to prevent or treat frailty. Therefore, the major goal of this study is to test a drug with insulin-sensitizing and anti-inflammatory properties, such as metformin, as a novel intervention for frailty prevention. The investigators hypothesize that metformin will lead to reduced inflammation and insulin resistance present in older glucose-intolerant subjects and that these changes will consequently prevent the onset and/or progression of frailty in this sub-population of older adults. Subjects with impaired glucose intolerance will be enrolled in this study because this group encompasses approximately 1/3rd of the older population, this group is at increased risk for developing diabetes and frailty, and is the most likely to benefit from a potential anti-inflammatory and insulin-sensitizing intervention.