Validity of Color-Doppler Ultrasonography for Diagnosis of Peripheral Arterial Disease in Type 2 Diabetes with Normal Ankle-Brachial Index.

Peripheral arterial disease (PAD) is one of major risk factors for cardiovascular morbidity and mortality in diabetic patients. The incidence of PAD is 3-4 fold higher in patients with diabetes than non-diabetic subjects. Moreover, the characteristics of PAD are much extensive but frequently asymptomatic in diabetic subjects compared to normal subjects. The ankle-brachial index (ABI) has been used to screen PAD but, more effective screening tool is needed to detect asymptomatic PAD in diabetic patients, especially with medial sclerosis. We investigated the usefulness of color Doppler ultrasonography and carotid intima-media thickness (C-IMT) for diagnosis of PAD in diabetic subjects with normal ABI. We enrolled 256 patients (mean age 62±9 yr, Male 62%) with type 2 diabetes from 2003 to 2006. All patients were performed ABI, color Doppler ultrasonography and C-IMT. We had checked past and current medical history and clinical symptoms of subjects at the time of procedure. The degree of stenosis in PAD was defined according to Jager's criteria. Among 256 patients, ABI values were normal (>0.9) in 232 (91%) and abnormal(≤0.9) in 24 (9%). Among the 232 patient with normal ABI, 22 (18%) had Grade III (50%-99% stenosis) lesions and 32 (14%) had Grade IV (100% stenosis) lesions by color Doppler ultrasonography. Most subjects with diagnosis of PAD are asymptomatic (78%). Most lesions were infra-popliteal (58%) and multi-segmental involvement reached up to 25%. In multivariate logistic regression, high C-IMT (≥ 1.0mm) was independent predictor for PAD (RR 3.4, 95% C.I. 1.5-7.5, p<0.05) after adjusting confounding factors (age, sex, smoking history, leg symptom, duration of diabetes) Our data suggest that color Doppler ultrasonography could be an important non-invasive tool for early diagnosis of asymptomatic PAD in diabetic patients, especially with high C-IMT (≥l.0mm) even though in patients with normal ABI. [ABSTRACT FROM AUTHOR]