Low Blood Flow Estimates in Lower-Leg Arteries Predict Cardiovascular Events in Japanese Patients With Type 2 Diabetes With Normal Ankle-Brachial Indexes

Abstract

OBJECTIVE -To examine the association of baseline measures in lower-leg arteries and conventional cardiovascular risk factors with the incidence of cardiovascular disease (CVD) events in type 2 diabetic patients with normal ankle-brachial indexes (ABIs) (Ͼ0.9).RESEARCH DESIGN AND METHODS -We studied 129 type 2 diabetic patients and 35 age-matched nondiabetic subjects with no apparent CVD consecutively admitted to our hospital. At baseline, total flow volume and resistive index, as an index of vascular resistance, at the popliteal artery was evaluated using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging. Patients were followed 4.8 Ϯ 1.5 years (range 3.0 -8.2) or until their first event of CVD.RESULTS -On follow-up, 16 patients developed primary CVD events. Patients with CVD had lower blood flow (P Ͻ 0.01) and higher vascular resistance (P Ͻ 0.05) than patients without CVD. When the patients were grouped into tertiles according to their levels of total flow volume (129.6 -85.5, 85.3-63.3, and 62.7-23.8 ml/min), Kaplan-Meier analysis showed a higher probability of developing CVD events in patients in the lowest than in patients in the highest (P ϭ 0.0199, log-rank test) tertile. Multivariate Cox proportional hazards analysis revealed that the lowest tertile for flow volume (hazard ratio [HR] 8.60, 95% CI 1.61-45.97, P ϭ 0.012), hypertension (3.99, 1.12-14.25, P ϭ 0.033), and smoking status (12.01, 1.21-119.28, P ϭ 0.034) were significant independent predictors of CVD events.CONCLUSIONS -We have demonstrated that low blood flow estimates in lower-leg arteries may be predictive for CVD events among Japanese patients with type 2 diabetes even though they have a normal ABI. Diabetes Care 29:1884 -1890, 2006D iabetic patients are likely to develop cardiovascular disease (CVD), including stroke, myocardial infarction, and peripheral artery occlusive disease (PAOD) (1). These manifestations of atherosclerosis frequently coexist in the same individual (2). Therefore, to identify these patients before the onset of CVD, ankle-brachial index (ABI) is generally used as a predictive marker of CVD (3).Furthermore, diabetic patients with chronic hyperglycemia are known to have stiffer arteries (4). Arterial stiffness leads to increased systolic pressure and ventricular mass and hampers coronary filling during diastole; therefore, increased arterial stiffness may play a role in the development of CVD (5). Changes of vessel wall properties, such as nonenzymatic glycosylation of matrix proteins (6), increased intima-media thickness (7,8), and radiographically detectable medial arterial calcification (9,10) may be involved in the pathogenesis of vascular rigidity.When the atherosclerotic plaques are at an advanced stage, calcified deposits in the coronary arteries are found more frequently and in greater amounts (11). Although the detection of coronary calcium deposits by electron-beam computed tomography does not indicate the location or severity of atherosclerotic lesions, this imaging procedure can predi...

Association of borderline ankle-brachial index with mortality and the incidence of peripheral artery disease in diabetic patients

“…The impairment of the elastic and muscular arteries in diabetes [25], resulting in poorly compressible vessels, which can increase the apparent ABI values [17]. There is a report that diabetic patients with ABI>0.90 had low blood flow in the lower-leg arteries [26], which suggested that measured ABI values might not reflect the actual condition of the peripheral arteries, particularly in diabetes. We might miss the patients with PAD if we adopt the current cutoff value of ABI 0.90 in diabetic patients.…”

Elevated plasma B-type natriuretic peptide concentration and resistive index, but not decreased aortic distensibility, associate with impaired blood flow at popliteal artery in type 2 diabetic patients

“…It has been reported that nondiabetic subjects had a typically triphasic waveform, which could be clearly separated into systolic and early and late diastolic phases of the cardiac cycle at popliteal artery [4,5]. Our waveform analyses showed diabetic patients to have lower systolic, late diastolic and total flow volumes at popliteal artery than those in nondiabetic subjects.…”

“…Total flow volume and flow components during the cardiac cycle at the popliteal artery were obtained. The instantaneous flow volume at 20 equally spaced time points through the cardiac cycle was calculated from the individual velocity images by integrating the velocity across the area of the vessel [4,5]. A resistive index, which reflects peripheral vascular resistance, has been defined as (A-B)/A, where A is the systolic peak velocity and B is the end-diastolic velocity [18].…”

“…These patients are characterized by higher incidence of cardiovascular disease events [5]. In Japan, the frequency of diabetic patients with low ABI is 7.6% [6], which is 3-fold higher than that in the general population [7].…”

Prognostic Values of B-Type Natriuretic Peptide and C-Reactive Protein for Predicting Cardiovascular Risk in Patients with Type II Diabetes Mellitus

“…It seems that these patients had a high occurrence of cardiovascular events in this study. These results are reported to be dependent on the study population, with the range between 10%–22% during patient follow-up (Booth et al 2006; Yoshimura et al 2006; Wilcox et al 2007). It is of note that cardiovascular event increases up to 50% in those who had suffered from myocardial infarction (Murcia et al 2004).…”