Ankle brachial index as a surrogate to vascular imaging in evaluation of peripheral artery disease in patients with type 2 diabetes

Background Peripheral artery disease (PAD) is common in persons with type 2 diabetes (T2DM) and contributes significantly to cardiovascular morbidity and mortality. Controversy exists regarding the utility of ankle brachial index (ABI) for clinical diagnosis of PAD in persons with diabetes. The aim of this study was to evaluate the reliability of ABI for diagnosis of PAD in patients with T2DM using duplex ultrasonography (DUS) as the gold standard. Results A total of 319 legs from 163 patients comprising of 156 subjects with intact legs and 7 patients who had undergone unilateral lower limb amputations were studied. The mean age of the participants was 56.1 ± 17.3 years. One hundred and ninety-five legs (61.1%) had sonographically confirmed PAD which was mild, moderate and severe in 40%, 41.5% and 18.5% respectively. The accuracy of ABI in detecting PAD was 76.7% for mild stenosis, 91.7% for moderate stenosis and 93.1% for severe stenosis. The sensitivity of ABI improved with increasing severity of arterial stenosis, reaching 100% in severe cases. ABI demonstrated good agreement with DUS [kappa = 0.65 (95% CI 0.49–0.88), P < 0.001]. Conclusion In comparison to DUS, the ABI demonstrated good reliability for diagnosis of PAD in high risk T2DM patients. The utility of this simple and non-invasive procedure should therefore be maximized in clinical practice.