Altered pressure flow relationship in the diabetic foot

This study was designed to evaluate the relationship between blood pressure and flow to the foot of diabetics as compared with a control nondiabetic population matched in age and degree of macrovascular disease involvement. Nineteen nondiabetic controls and 20 diabetic patients were investigated. The diabetic group was further subdivided into long (greater than 10 years) and short (less than 10 years) duration of disease. Foot blood flow was measured by venous occlusion plethysmography at rest and during reactive hyperemia. Systolic blood pressure at the ankle and great toe was assessed by noninvasive techniques. Peripheral resistance at rest and during hyperemia was clearly increased in the diabetic group when compared with the control subjects. In addition, for an equal level of foot blood pressure, the diabetics exhibited a lesser flow response compared to their nondiabetic counterparts. The changes were more marked in the long duration diabetic subgroup.