Lower-limb vascularization in diabetic patients - Assessment by thallium-201 scanning coupled with exercise myocardial scintigraphy

OBJECTIVE - To investigate, by thallium-201 scanning, circulation in the mu scles of the lower limb (LL) in diabetic patients without clinical peripher al vascular disease but with a high cardiovascular risk profile. RESEARCH DESIGN AND METHODS - A total or 80 diabetic patients (76 patients with type 2 diabetes, mean age 57.3 years, duration of diabetes 13.0 +/- 7. 5 years) with more than one additional cardiovascular risk factor but no cl audication were investigated. After stress testing, 1.5 MBq/kg thallium-201 was administered to perform myocardial single-photon emission computer tom ography followed by LL scanning. Muscle blood now was considered abnormal i t the asymmetry in thallium-201 uptake between the two buttocks and/or thig hs and/or calves was >10%. RESULTS - Muscle perfusion defects were found in 42% of the patients, mainl y in the calves. These defects correlated with retinopathy (P = 0.042) and the HbA(1c) level (P = 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 = 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 circ ulation. Proximal perfusion defects in patients without clinical arterial d isease are associated with increased prevalence of retinopathy and nephropa thy and, therefore, may be due to microvascular disease of LL muscle Distal defects may indicate silent macrovascular disease of the LL.