A Comparative Study of Topical Insulin Application Over Diabetic Foot Ulcers Versus a Normal Saline dressing

Abstract

Introduction: Diabetic foot ulcer (DFU) is a major complication of diabetes mellitus and an important cause of prolonged hospitalization and lower limb amputation. Delayed wound healing in diabetic ulcers is associated with impaired angiogenesis, chronic inflammation, and reduced cellular proliferation. Topical insulin has been reported to promote fibroblast proliferation, collagen synthesis, and angiogenesis, thereby enhancing wound healing. However, clinical evidence remains limited and heterogeneous in terms of study design and outcomes. The present study aimed to compare the effectiveness of a topical insulin dressing with a conventional normal saline dressing in patients with DFUs. Materials and methods: A non-randomized prospective comparative study was conducted in the Department of General Surgery at Shri B.M. Patil Medical College Hospital and Research Centre, Vijayapura. A total of 94 consecutive patients with Wagner grade 1 and 2 DFUs were included. Patients in the insulin dressing group received topical insulin dressings, while the comparison group received conventional normal saline dressings. Allocation to treatment groups was based on the treating surgeon's preference as part of routine clinical practice (non-randomized). Wound assessments were performed weekly to evaluate granulation tissue formation, wound surface area, and the presence of wound discharge. Additionally, percentage wound reduction, duration of hospital stay, time to complete ulcer closure, and final surgical outcomes were assessed. Results: Baseline characteristics were comparable between the groups. The insulin group demonstrated significantly higher granulation tissue formation from week 1 onward compared with the saline group. Mean wound reduction was significantly greater in the insulin group (48.44 ± 5.76%) compared with the saline group (19.15 ± 4.34%). Persistent wound discharge was observed in 11 (23.4%) patients in the saline group at week 1 and 7 (14.9%) at week 2, while no patients in the insulin group had discharge during these periods. The mean hospital stay was shorter in the insulin group (14.89 ± 1.90 days) compared with the saline group (19.21 ± 2.17 days). Similarly, time to complete ulcer closure was shorter in the insulin group (33.4 ± 3.7 days) than in the saline group (52.8 ± 5.2 days). No hypoglycaemia or systemic adverse effects were observed. Conclusion: Topical insulin dressing was associated with improved wound healing outcomes in patients with DFUs and appears to be a safe adjunct to conventional wound care. However, given the non-randomized design, these findings should be interpreted as associative rather than causal, and further randomized controlled studies are required.