Diabetes Care, Vol 21, Issue 4 580-584, Copyright © 1998 by American Diabetes Association
Low-intensity laser irradiation improves skin circulation in patients with diabetic microangiopathy
A Schindl, M Schindl, H Schon, R Knobler, L Havelec and L Schindl
Division of Special and Environmental Dermatology, University of Vienna Medical School, Austria. andreas.schindl@akh-wien.ac.at
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.