Abstract 4140064: Income and Mobility Loss in Peripheral Artery Disease

Introduction: Lower income is associated with a higher prevalence of peripheral artery disease (PAD). However, whether lower income is associated with faster rates of mobility loss among people with PAD is unknown. This study describes associations of income with mobility loss in people with PAD. Methods: Data from four longitudinal studies of participants with PAD conducted in Chicago were combined (the Walking and Leg Circulation Study [WALCS] I, II, and III and the Biomarker Risk Assessment in Vulnerable Outpatients [BRAVO] study). Participants with an ankle brachial index (ABI) <0.90 were categorized at baseline into quartiles of median income derived from their residence zip code. Mobility loss was assessed via participant report and a 6-minute walk test at baseline and annually. Among participants able to walk up one flight of stairs or walk ¼ mile without assistance at baseline, self-reported mobility loss was defined as becoming newly unable to climb one flight of stairs or walk ¼ mile without assistance. Objectively measured mobility loss was defined as becoming unable to complete the 6-minute walk without stopping among participants who completed the 6-minute walk without rest at baseline. Cox regression was used to evaluate relationships between income and mobility loss, adjusting for age, sex, race, cohort, BMI, smoking, and comorbidities. Results: A total of 1133 participants (n=451 [40%] women, n=288 [25%] Black, mean [SD] ABI 0.65 [0.15]) were included. Mean follow-up was 4.5 years. Rates of becoming unable to walk for 6 minutes without stopping were significantly higher among people with lower income, defined by zip code (P trend = 0.001). Conclusions: Among people with PAD, lower income defined by zip code of residence was associated with a significantly higher rate of mobility loss. Future studies should identify the factors that explain the associations reported here and identify interventions to overcome them.