Thermographic measurement of skin temperature recovery time of extremities in patients with type 2 diabetes mellitus.

To elucidate the relationship between the recovery of skin temperature in an extremity after exposure to cold water and various factors associated with diabetes, we measured skin temperature in type2 diabetic patients (N=61) and control subjects (N=16). A thermo-tracer was used in thermographic measurements. The right third toe of each subject was immersed in cold water at 0 degrees C for 10 sec. Rt represents the recovery rate of skin temperature at t min after exposure. Rt was significantly reduced in the diabetic patients every 5 min in the 20 min period following exposure compared with control subjects. The diabetic patients group exhibited a significantly positive correlation between R20 and the ankle-brachial index. R20 in the diabetic patients showed a significantly positive correlation with the reduction in systolic blood pressure at the arm observed in Schellong's test. In addition, R20 showed a significantly negative correlation with plasma levels of fibrinogen and plasminogen activator inhibitor-1. However, the severity of diabetic retinopathy and nephropathy was not significantly related to R20 in the diabetic patients. The present data indicate that the recovery of skin temperature after immersion in cold water was markedly reduced in patients with type 2 diabetes mellitus as compared with healthy control subjects. Peripheral arteriosclerosis, impaired sympathetic nerve function and the activation of the blood coagulation system may all contribute to this reduced recovery of skin temperature.