Peripheral Artery Disease, Diabetes, and Reduced Lower Extremity Functioning

OBJECTIVE: To characterize lower extremity function and dysfunction in peripheral artery disease (PAD) patients with and without diabetes. RESEARCH DESIGN AND METHODS: In this cross-sectional study, 460 men and women with PAD (147 with diabetes) were recruited from three academic medical centers. Assessments included ankle brachial index (ABI), neuropathy score, 6-min walk distance, 4-m walking velocity, Walking Impairment Questionnaire (0-100 scale, 100 = best), and summary performance score (SPS) (0-12 scale, 12 = best). RESULTS: The mean ABI was similar in PAD patients with and without diabetes. PAD patients with diabetes were younger, had a higher BMI, had a worse neuropathy score, and had a greater number of cardiovascular comorbidities compared with those without diabetes. Participants with diabetes were less likely to report classical symptoms of intermittent claudication and more likely to report exertional leg pain, which sometimes started at rest. After adjusting for age, those with diabetes had a shorter mean 6-min walk distance (1,040 vs. 1,168 feet, P < 0.001), slower fast-pace 4-m walk velocity (0.83 vs. 0.90 m/sec, P < 0.001), and a lower SPS (7.3 vs. 8.6, P < 0.001) than those without diabetes. Patients with diet-controlled diabetes performed better than those on diabetes medications. Differences in lower extremity functioning between patients with and without diabetes were largely attenuated but not abolished for SPS and fast-pace 4-m walk velocity after adjustment for type of exertional leg pain, neuropathy score, and number of cardiovascular comorbidities. CONCLUSIONS: Subjects with PAD and diabetes have poorer lower extremity function than those with PAD alone. This difference in functioning appears to be largely explained by diabetes-associated neuropathy, differences in exertional leg symptoms, and greater cardiovascular disease in patients with diabetes.