Abstract 15185: Midlife Cardiorespiratory Fitness and the Development of Peripheral Artery Disease in Later Life
Background: Data are sparse on the prospective associations between physical activity and the development of lower extremity peripheral artery disease (PAD). To our knowledge, the association between objectively measured cardiorespiratory fitness (fitness) levels and incident PAD has not been studied. Therefore, we sought to characterize the association between midlife fitness levels in healthy adults with long-term risk for PAD.
Methods: Linking individual participant data from the Cooper Center Longitudinal Study with Medicare claims files, we studied 20,581 participants (21% women) with fitness measured in middle-age (mean 49 years) and who survived to receive Medicare coverage from 1999 to 2009. Fitness was categorized into age- and sex-specific quintiles (Q) according to Balke protocol treadmill time, with Q1 as low fitness. Associations between midlife fitness and incident PAD events (PAD-related hospitalizations and/or surgical/endovascular procedures) after age 65 were assessed by applying a proportional hazards model to multivariate failure time data.
Results: After 133,052 person-years of Medicare follow-up (median follow-up: 26 years), we observed 1,061 PAD-related events in 872 participants. We observed a graded response across strata of midlife fitness and incident PAD in older age [Low (Q1): 20.4; moderate (Q2-3): 13.9; and high fitness (Q4-5): 10.0 per 1,000 person years]. After multivariable adjustment for common predictors of incident PAD, these findings persisted (Table). We observed similar results when fitness was analyzed based on number of metabolic equivalents [METs] achieved.
Conclusions: Cardiorespiratory fitness in healthy, middle-aged adults is associated with a significantly lower risk for PAD-related hospitalizations and/or procedures in later life, independent of other common predictors of incident PAD. Further study is needed to determine whether improving fitness protects against the development of PAD.
- © 2013 by American Heart Association, Inc.