OBJECTIVE -To investigate, by thallium-201 scanning, circulation in the muscles of the lower limb (LL) in diabetic patients without clinical peripheral vascular disease but with a high cardiovascular risk profile. RESEARCH DESIGN AND METHODS-A total of 80 diabetic patients (76 patients with type 2 diabetes, mean age 57.3 years, duration of diabetes 13.0 Ϯ 7.5 years) with more than one additional cardiovascular risk factor but no claudication were investigated. After stress testing, 1.5 MBq/kg thallium-201 was administered to perform myocardial single-photon emission computed tomography followed by LL scanning. Muscle blood flow was considered abnormal if the asymmetry in thallium-201 uptake between the two buttocks and/or thighs and/or calves was Ͼ10%.RESULTS -Muscle perfusion defects were found in 42% of the patients, mainly in the calves. These defects correlated with retinopathy (P ϭ 0.042) and the HbA 1c level (P ϭ 0.044). In patients with defects in the buttock and/or thigh, the prevalence of nephropathy and retinopathy was higher than in those with isolated defects in the calf (P ϭ 0.032 and 0.023, respectively).CONCLUSIONS -This study suggests that LL scanning coupled with myocardial scintigraphy is a convenient method of investigating peripheral muscle circulation. Proximal perfusion defects in patients without clinical arterial disease are associated with increased prevalence of retinopathy and nephropathy and, therefore, may be due to microvascular disease of LL muscle. Distal defects may indicate silent macrovascular disease of the LL. Diabetes Care 24:870 -874, 2001A fter 38 years of follow-up, the Framingham Heart Study showed that the risk of developing intermittent claudication was increased by associated coronary heart disease and diabetes (1). The prevalence of coronary artery disease and peripheral vascular disease (PVD) is high in the diabetic population (2,3).More than 50% of diabetic patients die from cardiovascular diseases (4), and the morbidity due to PVD is very high (5). Furthermore, claudication is, in turn, a strong predictor of subsequent cardiovascular events (6 -8).In diabetic patients with other risk factors, myocardial scintigraphy is suggestive of silent myocardial ischemia (SMI) in 20 -30% of cases (9). These patients commonly have angiographically normal coronary arteries and endothelial dysfunction, and myocardial microvascular changes are involved (10). Whole-body exercise thallium-201 ( 201 Tl) scintigraphy, performed after stress testing, permits detection of early functional abnormalities of lower-limb (LL) vascularization (11)(12)(13)(14)(15)(16)(17)(18)(19). Furthermore, this test investigates not only macrovascular but also microvascular blood flow (12,19).We performed myocardial 201 Tl scintigraphy after stress testing to detect SMI in a selected population of diabetic patients without claudication and without cardiac symptoms and signs but with a high cardiovascular risk profile. We took this opportunity to perform LL scanning. In particular, we examined the prevalen...

No abstract

No abstract

No abstract