Low-Dose Insulin as an Antiscarring Therapy in Breast Surgery: A Randomized Controlled Trial

Background: The role of insulin in expediting wound healing is firmly established within the context of major trauma and burns; however, only limited clinical evidence exists as to its effects on scar formation. This study aims to build on previous laboratory work to examine the potential antiscarring properties of insulin in a clinical environment. Methods: Ninety-one patients undergoing bilateral aesthetic breast operations were recruited to receive low-dose insulin and placebo injections to the medial 3 cm of their submammary incisions within the context of a randomized, intrapatient, placebo-controlled trial, and scar quality was assessed at 3-, 6-, and 12-month reviews using the Manchester Scar Scale. Results: Across the cohort at 12-month review, the insulin-treated scars had lower scar scores (p = 0.055) compared with placebo. Subgroup analysis of individuals with heavier scars showed that median scar scores were significantly lower for the insulin-treated scars with regard to both scar contour (p = 0.048) and scar distortion (p = 0.045). Conclusions: Subcutaneous insulin injections reduced the appearance of scarring in this study compared with placebo. The greatest effect was seen in those participants who showed heavier scars and, as such, insulin has a role as an antiscarring therapy in individuals likely to be affected by heavier scarring. Further research is required to more precisely delineate which subjects may benefit most from this treatment. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.