Low-intensity laser irradiation improves skin circulation in patients with diabetic microangiopathy.

ABSTRACT

OBJECTIVE: Diabetic foot problems due to angiopathy and neuropathy account for 50% of all nontraumatic amputations and constitute a significant economic burden to society. Low-intensity laser irradiation has been shown to induce wound healing in conditions of reduced microcirculation. We investigated the influence of low-intensity laser irradiation by means of infrared thermography on skin blood circulation in diabetic patients with diabetic microangiopathy. RESEARCH DESIGN AND METHODS: Thirty consecutive patients with diabetic ulcers or gangrenes and elevated levels of glycosylated hemoglobin were randomized by blocks of two to receive either a single low-intensity laser irradiation with an energy density of 30 J/cm2 or a sham irradiation over both forefoot regions in a double-blind placebo-controlled clinical study. Skin blood circulation as indicated by temperature recordings over the forefoot region was detected by infrared thermography. RESULTS: After a single transcutaneous low-intensity laser irradiation, a statistically significant rise in skin temperature was noted (P < 0.001 by ANOVA for repeated measurements), whereas in the sham-irradiated control group, a slight but significant drop in temperature (P < 0.001) was found. Subsequently performed contrasts for comparison of measurements before and after irradiation revealed significant temperature increases at 20 min of irradiation time (P < 0.001), at the end of the irradiation (P < 0.001), and 15 min after stopping the irradiation (P < 0.001). In the sham-irradiated feet, the drop in local skin temperature was not significant at 20 min (P = 0.1), but reached significance at the end of the sham-irradiation procedure (P < 0.001) and 15 min after the end of sham irradiation (P < 0.001). CONCLUSIONS: The data from this first randomized double-blind placebo-controlled clinical trial demonstrate an increase in skin microcirculation due to athermic laser irradiation in patients with diabetic microangiopathy.