Study of the Efficacy of Automated Oscillometry in Evaluating Ankle-Brachial Index for the Assessment of Peripheral Arterial Disease in Diabetes Mellitus

ABSTRACT

Peripheral arterial disease (PAD) is defined as a clinical disorder in which there is stenosis or occlusion in the aorta orarteries of the limbs. Type 2 diabetes is a strong risk factor for atherosclerotic diseases including cardiovascular aswell as peripheral arteries. The risk of development of peripheral arterial disease increases three to four folds inpatients with diabetes.Most diabetic amputations are due to peripheral arterial disease (PAD), peripheral neuropathyand infection. Ankle-brachial index is helpful in assessing the prognosis in the symptomatic as well as asymptomaticpatients in contrast to the variability of pulse assessment and the physical examination. The present study included50 patients with diabetes mellitus for more than ten years, irrespective of their symptoms. ABI was calculated bydividing the ankle systolic blood pressure by the brachial systolic blood pressure of the respective sides. The lowerof the two ABI values for the legs was used to define ankle brachial index. Of 50 patients, 20 had signs of PAD amongwhom 11 (55.0%) had abnormal ABI and 9 (45.0%) had normal ABI. Out of 30 patients with no signs of PAD, 8 (26.7%)had abnormal ABI and 22 (73.3%) had normal ABI. Automated oscillometry method for evaluating ankle-brachialindex for the assessment of peripheral arterial disease in diabetes mellitus had a sensitivity of 68.18%, a specificity of85.71%, positive predictive value (PPV) of 78.95% and negative predictive value (NPV) of 77.42%. The Accuracy ofthe test was 78.0%. Thus, our study has proved that the oscillometric method of ABI is a very useful procedure fordetecting PAD. By repeating the test the sensitivity and specificity may probably increase. The oscillometric methodof performing ABI is a simple procedure, automated, easy to perform, negligible cost of the instrument, does notrequire training and can be performed as an outpatient procedure.