Abstract 32: Joint Associations of Peripheral Artery Disease and Objectively-measured Physical Activity With Mortality: The Hispanic Community Health Study / Study of Latinos

Abstract

Background: Peripheral artery disease (PAD) reduces physical activity, and both PAD and lower physical activity levels have been shown to increase mortality risk. Yet, their joint contributions to mortality have not been systematically studied, especially with the objective measure of physical activity. Hypothesis: PAD and lower 1-week objectively-measured physical activity are synergistically associated with mortality. Methods: We studied 7124 Hispanic adults aged 45-74 years at baseline from the Study of Latinos who adhered to an objective measure of physical activity using wearable accelerometers. We quantified the associations of the status of PAD (ankle-brachial index [ABI] ≤0.90 [PAD], 0.91-1.39 [no PAD], and ≥1.40 [possible PAD with ankle artery calcification]) and two physical activity measures (sedentary time [tertiles] and daily physical movement counts [tertiles]) at baseline with mortality using multivariable Cox models accounting for sampling weights. Results: During a median follow-up of 7.0 years, 289 participants died. Sedentary time and daily physical movement counts were weakly correlated (r=-0.17). Both low and high ABI, longer sedentary time, and lower physical movement counts were all independently associated with increased mortality risk (marginal cells in Table ). In terms of the joint associations of PAD and physical activity with mortality, they generally demonstrated synergistic associations (e.g., hazard ratio 4.43 [95%CI, 2.44-8.03] in ABI ≤0.9 plus top tertile of sedentary time and 5.46 [2.47-12.08] in ABI ≥1.40 plus top tertile of sedentary time vs. normal ABI with shortest sedentary time) (cross-categories in Table ), with no significant interactions. Conclusions: Both low and high ABI, and lower objectively-measured physical activity levels were significantly associated with greater risk of mortality independently of each other and potential confounders. Our results suggest the importance of objectively evaluating daily physical activity levels and leg vascular condition.