Vascular Responses in Diabetic Peripheral Neuropathy

Abstract

Peripheral vascular responsiveness was studied in 12 young healthy subjects, in 15 elderly subjects without diabetes, and in 43 subjects with diabetes. Twenty-nine of the diabetic subjects had neurological signs and 14 did not. Vasomotor responses to body-heating and cooling, local heating and cooling, and to the injection of adrenaline were measured by the continuous recording of digital skin temperatures. Reflex vasomotor responses in the feet were completely absent in 16 of the diabetic subjects with, and in three of those without, other peripheral neurological signs. The pattern of vascular responsiveness in these feet was characteristic of denervation hypersensitivity. They exhibited autonomous vasomotor tone which was independent of body temperature, but which was readily augmented by local cold or by the injection of minute amounts of adrenaline. Reflex vasomotor responses in the feet were present, but delayed, in four of the elderly non-diabetic subjects, and in nine of the diabetic subjects with, and two of those without, other neurological signs. It was not determined whether reactivity of this type was due to partial sympathetic denervation, partial arterial occlusion, or both. The presence of cold-sensitivity due to sympathetic denervation in the peripheral vasculature of patients with diabetic neuropathy has not been generally recognized. It often causes discomfort, and sometimes pain ; it may augment the development of trophic ulcers ; and it may lead to unnecessary surgery by interfering with the assessment of the circulation in diabetic limbs. © 1966, British Medical Journal Publishing Group. All rights reserved.