Muscle weakness among older adults: A silent epidemic
Investigators: Philippa J. Clarke
Funding: Michigan Center on the Demography of Aging, 2016-2017
Muscle weakness, referred to as "dynapenia", is a primary determinant of age-related loss of function and has been implicated in the development of future mobility disability, cardiovascular disease and even mortality. Hand grip strength, a reliable and cost-effective surrogate of overall muscle strength, is a robust prognostic indicator of weakness and subsequent functional limitations. Despite the well-known links between muscle weakness and a host of negative health outcomes, the determination of how we identify weak individuals has not been established using nationally representative data. Most recently, we employed Classification and Regression Tree (CART) models to derive hand grip strength cutpoints for dynapenia in the Health and Retirement Study (HRS) (manuscript under review, Duchowny et al.) as a critical first step in identifying at risk individuals. While we applied these cut-points cross-sectionally to examine the prevalence of dynapenia at the population level, it is unclear the extent to which these cut-points predict health outcomes for different sex and racial/ethnic group over time. The current proposal will chart new territory in investigating the long-term health consequences of dynapenia to: 1) predict whether individuals who fall below these proposed cut-points are at risk for developing future negative health outcomes; 2) examine proposed cut-points in predicting future health risks above and beyond traditional indicators of morbidity and mortality; and 3) understand the role obesity may play in exacerbating future negative health outcomes among those who are considered weak.