Osteopontin levels in plasma, muscles, and bone in patient with non-healing diabetic foot ulcers: A new player in wound healing process?

Abstract Background The present study was designed to investigate the impact of osteopontin (OPN) in different tissue (e.g., plasma, muscles and bone) on amputation rate (in-hospital and during one year follow-up) for non-healing diabetic foot ulcers (DFUs). Methods This pilot study consisted of 30 diabetic patients, hospitalized due to non-healing DFUs. Patients were divided into two groups: Group 1 included 14 patients who underwent limb-preserved debridement procedure without amputation; Group 2 included 16 subjects who underwent amputation. Additionally, recurrent amputation rate during 1 year follow-up was investigated. Results Plasma OPN was higher and bone OPN was lower in Group 2 compared to Group 1 ( p  = 0.016 and p  = 0.004, respectively). In the logistic regression analysis, bone OPN emerged as a significant independent predictor of amputation (OR = 0.042, 95% CI 0.003–0.699, p  = 0.027). Plasma OPN was also associated with amputation such that each unit increase in plasma OPN was associated with an increase in odds of amputation of 17.7% (95% CI 0.997–1.388, p  = 0.045). During 1 year follow-up 11 patients underwent recurrent amputation. Plasma OPN were higher and bone osteopontin was lower in patients who underwent amputation compared to patients who did not need amputation at one year follow-up. However, in GLM analysis bone OPN was only marginally associated with one year amputation (OR 0.001, 95% CI 0.000–2.0, p  = 0.076). Conclusions Decreased levels of OPN in bone and increased plasma OPN are independently associated with in-hospital amputation. Consequently, plasma OPN may be relevant in the routine assessment of amputation risk in this patient population.