Abstract 13904: Associations of the Ankle Brachial Index With Functional Decline According to Presence or Absence of Diabetes

Abstract

Introduction: Among patients with peripheral artery disease (PAD), there is an inverse association between the ABI and the risk of functional decline. Whether the association is consistent for adults with vs without diabetes is unknown. Methods: Adults with PAD (ABI<0.90) were identified from vascular labs and outpatient clinics from 4 Chicago-area hospitals in a pooled analysis of 4 observational studies. Every 6-12 months participants completed the six-minute walk (6MW) and were asked about mobility loss (becoming unable to walk up and down a flight of stairs or walk ¼ mile without help). Mixed-effects linear regression analysis with a subject-specific random intercept was used to calculated annual change in 6MW, stratified by diabetes status. Cox proportional hazards models were used to estimate the risk of mobility loss, a decline in 6MW ≥20m or having to stop during the 6MW, per unit increment of ABI (1 unit=0.15). Analyses were adjusted for age, sex, race, study cohort and comorbidities. Results: Among 1,135 patients with PAD, 409 (36%) had diabetes. Mean ABI was similar between groups (0.64 with diabetes, 0.65 without diabetes, p=0.4). Compared to those without diabetes, those with diabetes were older (71.4 vs 68.6, p<0.001) and had a higher BMI (30.5 kg/m 2 vs 27.3 kg/m 2 ). Mean follow-up was 3.3 years. At baseline those with diabetes had a shorter 6MW distance (320.2m vs 356.1m, p<0.001) and over follow-up had a faster rate of annual decline (-20m vs -14.5m, p<0.001). Among adults without diabetes the ABI was associated with stopping during the 6MW, mobility loss and a decline in 6MW ≥20m (Table); among adults with diabetes ABI was only associated with stopping during the 6MW. Conclusions: Among adults with PAD, those with diabetes had worse functional capacity at baseline and faster decline than those without diabetes. Lower ABI values were associated with faster functional decline among adults with PAD, but this association was less consistent among adults with diabetes.