Diabetes, Vol 37, Issue 6 714-716, Copyright © 1988 by American Diabetes Association
Transcutaneous oxygen tension in legs and feet of diabetic patients
PM Gaylarde, VA Fonseca, G Llewellyn, I Sarkany, PK Thomas and P Dandona
Department of Dermatology, Royal Free Hospital, School of Medicine, London, United Kingdom.
Transcutaneous oxygen tension (tcPO2) of the legs and feet was measured at
37 and 44 degrees C in 21 patients with diabetes mellitus, 9 of whom had
peripheral neuropathy. At 37 degrees C, tcPO2 in the legs and feet of
diabetic patients with peripheral neuropathy was significantly higher (P
less than .02) than in control subjects and diabetic patients without
neuropathy. Whereas tcPO2 in the legs of control subjects and
nonneuropathic diabetic patients was greater than in the feet (P less than
.02), this leg-to-foot difference was absent in diabetic patients with
neuropathy. After an increase in skin temperature to 44 degrees C, tcPO2
increased in the legs and feet of all three groups, but the increase was
smallest in diabetic patients with neuropathy and greatest in control
subjects. In neuropathic (P less than .02) and nonneuropathic (P less than
.02) diabetic patients, tcPO2 was significantly lower than in control
subjects. These data are consistent with a loss of vasoconstrictor tone in
the blood vessels perfusing skin and subcutaneous tissue at 37 degrees C
and an inability of these vessels to vasodilate and increase blood flow at
44 degrees C in diabetic patients in general and neuropathic diabetic
patients in particular. This inability to increase tcPO2 after an increase
in temperature and possibly other vasodilatory stimuli may contribute to
the pathogenesis of nonhealing ulcers, protracted infections, and gangrene,
which characterize the diabetic foot.