Pilot study of prevalence of asymptomatic peripheral arterial occlusive disease in patients with diabetes attending a hospital clinic

In a pilot study, we have estimated the crude prevalence of asymptomatic peripheral arterial occlusive disease (PAOD) in diabetic patients attending a hospital clinic, using the sensitive Doppler ultrasound measurement of systolic ankle brachial pressure index (ABPI). This was compared with the available clinical methods of PAOD detection, ie peripheral pulse palpation. We have also investigated whether the measurement of toe systolic pressure (TSP) improved the detection rate of PAOD amongst those who had a normal ABPI. Of the 48 patients studied, 12 had palpable dorsalis pedis and posterior tibial pulse and 36 had absent pulse. Patients were of both types of diabetes mellitus, had no history of cardiovascular or cerebrovascular disease and did not have symptoms suggestive of intermittent claudication. An ABPI value of>0.9 was taken as normal. TSP was assessed by a strain gauge method. All patients who had palpable pulses had an ABPI > 1.0 with median (range) 1.10(1.01–1.30). Of those who had impalpable pulses, 18 patients had evidence of significant peripheral arterial insufficiency with an ABPI median (range) of 0.76 (0.49–0.89) and 18 patients had a normal ABPI with median (range) of 1.08 (0.92–1.25). TSP measurements were not different from the ankle systolic pressure. The study groups were no different in terms of their duration of diabetes, smoking habit, Body Mass Index or glycated haemoglobin levels, but those in the group with a low ABPI were significantly older, p<0.05. The prevalence of asymptomatic PAOD in our study cohort was 33% We conclude that palpable pulses are a predictor of normal ABPI, but impalpable pulses are not a strong predictor of PAOD.