Abstract
BACKGROUND: Although supervised exercise therapy (SET) is effective in improving walking distance among adults with symptomatic peripheral artery disease (PAD), some research suggests that individuals with comorbid PAD and type 2 diabetes mellitus (T2DM) may experience a blunted response to SET. It is unknown whether free-living sedentary time changes during SET, and if increases in sedentary time could, in part, explain poor response to SET. The purposes of this pilot study were to (1) determine if older adults with PAD (with and without T2DM) engaging in SET change their sedentary behavior and (2) examine the relationship between changes in sedentary behavior and SET outcomes. We hypothesized that decreased sedentary time during SET would be associated with greater improvements in six-minute walk test (6MWT) total distance and other key SET outcomes. METHODS: Participants (n = 44) initiating a 12-week SET program completed the 6MWT, Short Physical Performance Battery, Walking Impairment Questionnaire, and accelerometer-assessed sedentary behavior at SET initiation, 6 weeks, and 12 weeks. RESULTS: Participants' mean age was 72.3 (7.1) years, mean ankle-brachial index was 0.71 (0.25), and 47.7% were female. On average, sedentary time did not change after SET, although there was substantial variability (-40% to +38% change in minutes of sedentary time/day). Participants with T2DM experienced greater improvements in claudication onset distance than participants without T2DM (mean = 35 m, P = 0.044, 95% confidence interval = 1.6 to 115.4 m). Neither changes in sedentary time from baseline to 6 weeks (P = 0.419) nor T2DM (P = 0.154) predicted changes in 6MWT total distance from baseline to 12 weeks. CONCLUSIONS: As SET availability increases, further examination of factors that may influence SET outcomes will help maximize benefits of this proven therapy.