Background— Although renal insufficiency is a recognized risk factor for coronary artery disease, little is known about the epidemiology of lower-extremity peripheral arterial disease (PAD) in persons with renal insufficiency.

Methods and Results— We examined the cross-sectional association of PAD, defined as an ankle-brachial index (ABI) <0.9, and renal insufficiency, defined as an estimated creatinine clearance (CRCL) <60 mL · min⁻¹ · 1.73 m⁻², among 2229 eligible participants in the National Health and Nutrition Examination Survey (NHANES) 1999 to 2000. An estimated 1.2±0.3 million persons ≥40 years old with CRCL <60 mL · min⁻¹ · 1.73 m⁻² (24%) have PAD defined as an ABI <0.9 (versus 3.7% of persons with CRCL ≥60 mL · min⁻¹ · 1.73 m⁻²). The association of ABI <0.9 with renal insufficiency was independent of potential confounders such as age, diabetes, hypertension, coronary artery disease, stroke history, and hypercholesterolemia (OR 2.5, 95% CI 1.2 to 5.1, P=0.011, referent category ABI 1.0 to 1.3).

Conclusions— Clinicians should be aware of the remarkably high prevalence of PAD among patients with renal insufficiency. In the clinical setting, accurate identification of patients with renal insufficiency combined with routine ABI measurement in this group would greatly enhance efforts to detect subclinical PAD.