Effects of insulin on wound healing

Background: Insulin plus glucose, given for 7 days to hyper- metabolic burn patients, has been shown to stimulate limb protein anabolism. We hypothesized that insulin plus glucose given to burn patients would also stimulate wound healing. Methods: Six patients with burns >40% total body surface area were randomized to receive insulin or placebo in a crossover study during the healing of their first and second donor sites. Insulin treatment was titrated at 25 to 49 U/h to achieve a plasma insulin level of 400 to 900 μU/mL for 7 days. Patients receiving insulin received dextrose 50 at 20 to 50 mL/h, titrated to maintain euglycemia. Donor-site biopsies were taken at 7 days and evaluated by three observers blinded to the treatment. Results: The mean (±SD) donor-site healing time was reduced from 6.5 ± 1.0 days with placebo to 4.7 ± 1.2 days during insulin infusion (p < 0.05). Laminin showed intense staining along the basal lamina and blood vessels. Collagen type IV staining also increased after insulin therapy compared with placebo. Conclusion: Data indicate that high doses of insulin and glucose can be safely administered to massively burned patients to improve wound matrix formation.