Local Use of Insulin in Wounds of Diabetic Patients: Higher Temperature, Fibrosis, and Angiogenesis

Background: Clinical trials have shown the effectiveness of systemic and local insulin therapy in improving wound healing. Diabetic wounds remain a challenge for healthcare providers. Impaired angiogenesis and reduced granulation tissue formation contribute to inadequate wound healing. The aim of this study was to investigate the effect of local insulin administration in acute and chronic diabetic wounds. Methods: Eight diabetic patients presenting with full-thickness wounds, of different causes, were included in this study. Five wounds were due to necrobiosis, one to trauma, and two to postneoplasm resection. All wounds were treated with regular bedside treatment. In addition, half of the wound surface was treated with insulin and the other half did not receive insulin. Thermographic and biopsy specimens of the two sides were obtained on days 0 and 14. The presence of fibrosis, change in temperature, and amount of blood were evaluated. Results: Significant differences in the number of vessels were observed on the insulin-treated side (96 +/- 47) when compared with the no-insulin side (32.88 +/- 45) (p < 0.026). The percentage of fibrosis (insulin: 44.42 +/- 30.42 percent versus no insulin: 12.38 +/- 36.17 percent; p < 0.047) and the mean temperature (insulin: 1.27 +/- 1.12 degrees C versus no-insulin: 0.13 +/- 1.22 degrees C; p < 0.001) were also significantly different between sides. No adverse events related to the study occurred. Conclusion: The use of local insulin improves the formation of new blood vessels, increases fibrosis, and correlates with increased temperature.