Physical Activity During Daily Life and Functional Decline in Peripheral Arterial Disease

Background-Few modifiable behaviors have been identified that are associated with slower rates of functional decline in persons with lower-extremity peripheral arterial disease. We determined whether higher levels of physical activity during daily life are associated with less functional decline in persons with peripheral arterial disease. Methods and Results-The study population included 203 peripheral arterial disease participants who underwent vertical accelerometer-measured physical activity continuously over 7 days and were followed up annually for up to 4 years (mean, 33.6 months). Outcomes were average annual changes in 6-minute walk performance, usual-paced and fast-paced 4-m walking velocity, and the short performance physical battery. Analyses were adjusted for age, sex, race, comorbidities, body mass index, ankle brachial index, smoking, and walking exercise frequency. Higher baseline physical activity levels measured by a vertical accelerometer were associated with significantly less average annual decline in 6-minute walk performance (P for trend=0.010), fast-paced 4-m walking velocity (P for trend=0.002), and the short performance physical battery (P for trend=0.001). Compared with the lowest baseline quartile, those in the highest baseline quartile of physical activity had less annual decline in 6-minute walk performance (-50.82 versus -107.0 ft/y; P=0.019), fast-paced 4-m walking speed (-0.0034 versus -0.111 m . s(-1) . y (-)1; P = 0.002), and the short performance physical battery (-0.074 versus -0.829; P=0.005). Conclusions-Higher physical activity levels during daily life are associated with less functional decline among people with peripheral arterial disease. These findings may be particularly important for the large number of peripheral arterial disease persons without access to supervised walking exercise programs. (Circulation. 2009;119:251-260.)