Efficacy of insulin application in skin wound healing: a systematic review and meta-analysis

Objective: Insulin has been investigated for wound management, which is an ongoing challenge for clinicians. However, whether superior outcomes can be obtained by local application of insulin remains controversial. This study aimed to assess the efficacy of local insulin application on wound healing. Method: PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched for relevant studies. Randomised clinical trials (RCTs) investigating the effect of insulin application on any healing outcome, including wound healing time, healing speed and change in wound area, were considered for inclusion. Data were pooled using a random effects model to calculate the standard mean differences (SMDs) or weighted mean differences (WMDs) and 95% confidence intervals (CIs). Results: A total of 12 RCTs met the inclusion criteria and were included in this meta-analysis. The combined results showed that local application of insulin significantly shortened healing time (WMD: –4.82; 95% CI: –9.15, –0.49; p=0.029). Compared with control groups (treated with placebo), intervention groups displayed a significantly higher wound healing speed (SMD: 1.17; 95% CI: 0.75, 1.60; p<0.001). Furthermore, the reduction in wound area in the intervention groups was noticeably greater than that of the control groups (SMD: 0.80; 95% CI: 0.08, 1.52; p=0.029). Conclusion: The findings of this systematic review revealed that local insulin application contributed to wound repair, as indicated by decreased healing time, increased healing speed and greater wound area reduction in the studies included. Local insulin application therefore appears to be a reliable treatment option for wound management.