Summary. Measurements of transcutaneous oxygen tension were made on the foot and arm in 16 Type 1 (insulin-dependent) diabetic patients with no evidence of vascular or neurological disease on simple clinical examination and in 30 nondiabetic subjects. The mean transcutaneous oxygen tension measured at 45 ~ on the foot was significantly lower in the diabetic patients than in the non-diabetic subjects. The hyperaemic response in the arm after cuff occlusion (measured by transcutaneous oxygen tension at 37 ~ was also significantly lower in the diabetic patients. These results may reflect abnormal capillary blood flow in diabetic patients. As the methods are simple and non-invasive, they may prove useful in the early assessment and subsequent monitoring of peripheral vascular problems in diabetes.Key words: Transcutaneous oxygen tension, vascular response, Type 1 diabetes, capillary blood flow.The technique of transcutaneous oxygen tension (TcPO2) measurement can provide a non-invasive method of estimating both arterial PO2 and tissue perfusion [1]. If the vascular bed is maximally dilated by heating to 45 ~ and adequately perfused, there is a good correlation between TcPO2 values and arterial PO2 in healthy adults [2]. With the electrode operating at a lower temperature (usually 37 ~ the TcPO2 reading is then related to skin perfusion and the technique can be used to assess reactive hyperaemia in the skin [3].We have reported previously a reduction in TcPO2 values at 45 ~ in patients with peripheral vascular disease [4], but whether such abnormalities in TcPO2 can be detected in diabetic patients with no clinical evidence of vascular disease is unknown. Reduction in vascular reactivity in diabetic children has been reported [5] and we have, therefore, investigated a group of adult Type 1 (insulin-dependent) diabetic patients to determine whether there are any differences in TcPO2 or in vascular reactivity compared with normal subjects.
Patients and MethodsSixteen Type 1 diabetic patients, eight females and eight males, mean +SD age 28_6years (range 18-39years) were studied (Tablet). None had any symptoms of leg pain or claudication and all had palpable lower limp pulses including dorsalis pedis and posterior tibial pulses. Lower limb reflexes, pin prick and touch sensation and ankle vibration sense using a tuning fork (128 Hz) were also normal in all patients. Thirty normal subjects (11 females and 19 males) aged from 20 to 63 years were also studied. Twenty-two of this group (11 females and It males) were aged < 40 years (mean + SD: 28.4 + 6.1 years) and were used as control subjects. All gave informed consent. Six of the diabetic patients and 11 of the control subjects were regular smokers of 20-40 cigarettes daily. All subjects refrained from smoking for a minimum of 1 h before the procedure and were studied supine. The left arm and left foot were exposed and clothing loosened around the arm and leg to prevent any obstruction to blood flow. The examination room was maintained close to 26 ~ to prevent vasoconstri...