Altered tissue oxygen tension responsiveness in diabetes

Abstract

Subcutaneous oxygen tension (tissue PO2) was measured by a polarographic method in the legs of insulin-dependent diabetics (IDDM) and controls. Current flow was measured continuously using a five-stage protocol: baseline; 4 min of complete arterial occlusion; during recovery from ischemia; baseline approximately re-established; induction of hyperemia by local application of heat. Eleven patients with IDDM of 4-32 years of duration, without peripheral arterial disease, were studied and compared with 10 controls. The mean baseline subcutaneous PO2 in diabetics was less than controls; however, the difference was not statistically significant. At the end of arterial occlusion the mean decrease in tissue PO2 was less (P less than 0.025) in diabetics (4.7 +/- 0.9 mm Hg, SEM) compared to controls (10.2 +/- 1.6 mm Hg). With induction of hyperemia the increase in tissue PO2 was lower (P less than 0.001) in diabetics (7.4 +/- 0.4 mm Hg) than in controls (18.6 +/- 1.7 mm Hg). The observed differences provide for the first time direct evidence of altered tissue PO2 responses in diabetes.