The relationship between ankle-brachial index and leisure-time physical activity in patients with intermittent claudication.

The purpose of the study was to examine the relationship between ankle-brachial index (ABI) and leisure-time physical activity (LTPA) in patients with peripheral arterial disease limited by intermittent claudication. Patients included 342 sedentary men and women between the ages of 45 and 85 with intermittent claudication confirmed by a resting ABI of less than 0.90. Patients were categorized into either a low ABI group (ABI <0.50; n=84), a middle ABI group (ABI = 0.50 to 0.69; n=164), or a high ABI group (ABI = 0.70 to 0.89; n=94). The Minnesota LTPA questionnaire was used to estimate physical activity patterns, and a treadmill test, 6- minute walk test, and Walking Impairment Questionnaire were used to measure ambulatory function. A progressive decrease (p=0.030) in the total LTPA was observed among the high ABI (180 +/-131 kcal/day; mean +/- SD), middle ABI (138 +/-127 kcal/day), and low ABI (110 +/-89 kcal/day) groups. Progressive decrements in LTPA spent at moderate intensity (p=0.016) and high intensity (p=0.009), as well as the mean intensity of LTPA (p=0.024) were observed among the three respective ABI groups. Group differences in the LTPA measurements were no longer present (p>0.05) after adjusting for group differences in the absolute claudication distance during a treadmill test, and the 6-minute walk distance. The decline in total daily LTPA with progressively lower ABI in patients with intermittent claudication was due to their decreased participation in physical activities requiring moderate and high intensities. In addition, group differences in the LTPA measurements were explained by differences in ambulatory function.