Peripheral Artery Disease and Subsequent Risk of Infectious Disease in Older Individuals: The ARIC Study

Objective: To quantify the association of peripheral artery disease (PAD) with infection risk because PAD has been understudied despite recognition of atherosclerotic cardiovascular disease as a risk factor for infection. Methods: Among 5082 participants of the Atherosclerosis Risk in Communities study (aged 71 to 90 years during 2011-2013), we assessed the association of PAD status, based on clinical history and ankle-brachial index (ABI), with infection-related hospitalization (through December 2019) using multivariable Cox regression. We also cross-classified participants by PAD and coronary heart disease (CHD)/stroke status at baseline, with implications for polyvascular disease. Results: During the median follow-up of 6.5 years, there were 1677 infection-related hospitalizations. Peripheral artery disease (clinical history or ABI ≤0.90) was independently associated with the risk of overall infection (adjusted hazard ratio [HR], 1.66 [95% CI, 1.42 to 1.94] vs ABI of 1.11 to 1.20), as was borderline low ABI of 0.91 to 1.00 (adjusted HR, 1.75 [95% CI, 1.47 to 2.07]). Results were consistent across major types of infection (ie, cellulitis, bloodstream infection, pneumonia, and urinary tract infection). For overall infection, PAD plus CHD/stroke had the highest HR of hospitalized infection (1.9), and PAD alone and CHD/stroke alone showed similar HRs of 1.6. For subtypes of infection, PAD alone had the highest HR of approximately 2 for bloodstream infection; PAD alone and PAD plus CHD/stroke had a similar risk of urinary tract infection with HR of approximately 1.7. Conclusion: Peripheral artery disease and borderline low ABI were robustly associated with infection-related hospitalization of older adults. The contribution of PAD to infection risk was comparable to that of CHD/stroke, warranting clinical attention to PAD for the prevention of infectious diseases.