Noninvasive assessment of toe systolic pressures with special reference to diabetes mellitus

Toe and ankle systolic blood pressures were measured noninvasively in asymptomatic volunteers and in patients with peripheral arterial obstructive disease. The measurement of ankle pressure was falsely elevated in 23% (51/219) of the diseased limbs studied, as a consequence of partial or total vessel incompressibility caused by arterial calcification and rigidity. Eighty percent (41/51) of limbs with erroneous ankle pressure readings were from patients with diabetes mellitus. Toe pressure was the most reliable indicator of occlusive disease, and was able to assess disease distal to the ankle. Five groups were separated using the ankle-brachial and the toe-ankle systolic pressure ratios: normal, claudication, limb salvage, claudication/incompressible arteries, and limb salvage/incompressible arteries. Insulin dependent and orally-medicated diabetics predominated in the two groups with incompressible arteries. The toe-brachial systolic pressure ratio was an accurate hemodynamic indicator of total peripheral arterial obstructive disease.