Ankle-brachial index and physical function in older individuals: The Atherosclerosis Risk in Communities (ARIC) study

Background and aims Most prior studies investigating the association of lower extremity peripheral artery disease (PAD) with physical function were small or analyzed selected populations (e.g., patients at vascular clinics or persons with reduced function), leaving particular uncertainty regarding the association in the general community. Methods Among 5262 ARIC participants (age 71–90 years during 2011–2013), we assessed the cross-sectional association of ankle-brachial index (ABI) with the Short Physical Performance Battery (SPPB) score (0–12), its individual components (chair stands, standing balance, and gait speed) (0–4 points each), and grip strength after accounting for potential confounders, including a history of coronary disease, stroke, or heart failure. Results There were 411 participants (7.8%) with low ABI ≤0.90 and 469 (8.9%) participants with borderline low ABI 0.91–1.00. Both ABI ≤0.90 and 0.91–1.00 were independently associated with poor physical function (SPPB score ≤6) compared to ABI 1.11–1.20 (adjusted odds ratio 2.10 [95% CI 1.55–2.84] and 1.86 [1.38–2.51], respectively). The patterns were largely consistent across subgroups by clinical conditions (e.g., leg pain or other cardiovascular diseases), in every SPPB component, and for grip strength. ABI >1.3 (472 participants [9.0%]), indicative of non-compressible pedal arteries, was related to lower physical function as well but did not necessarily reach significance. Conclusions In community-dwelling older adults, low and borderline low ABI suggestive of PAD were independently associated with poorer systemic physical function compared to those with normal ABI. Clinical attention to PAD as a potential contributor to poor physical function is warranted in community-dwelling older adults.