When wounds are treated with regular insulin, they are also being treated with zinc; used in the formula to crystallize insulin molecules. It is not clear if regular insulin-accelerated wound healing is due to insulin, the zinc it contains, or both. Thus, we aimed to compare topical regular crystalline insulin (containing zinc) vs. aqueous zinc chloride solution to controls, on healing of open uncomplicated cutaneous wounds. In this randomized controlled pilot study, 90 nondiabetic patients were randomly assigned to one of three groups depending on the twice daily applications received; group I: regular insulin; group II: aqueous zinc chloride solution, and group III: 0.9% saline (control). A questionnaire was used to determine the effect of wounds on the quality of life. Both topical regular crystalline insulin (containing zinc) and aqueous zinc chloride solution enhanced healing of uncomplicated cutaneous wounds of nondiabetic patients, than control (p < 0.001), and hence improved patients' quality of life. However, regular insulin showed better results than aqueous zinc solution (p = 0.015), probably due to synergistic effect between insulin and zinc of its formulation. Healing rate was significantly higher in acute than chronic wounds (p < 0.001), in those ≤40 years than those >40 (p = 0.004), and in upper body wounds than lower body (p = 0.015).
© 2014 by the Wound Healing Society.