Red Blood Cell Distribution Width: A Novel Predictor of Mortality Following Amputation in Diabetic Foot

Abstract

Category: Diabetes; Other Introduction/Purpose: Red blood cell distribution width (RDW) reflects the degree of heterogeneity of erythrocyte volume. The number of studies investigating the relationship between RDW and various human disorders has exponentially increased over the past decades. However, the association of RDW with diabetic foot amputation has not been evaluated to date. In this study, we assessed the value of RDW as a prognostic factor in diabetic foot amputation. Methods: Data on 415 patients with diabetic foot who underwent amputation between January 2009 and January 2019 were analyzed retrospectively. After establishing optimal cut-off point of preoperative RDW for all-cause mortality, univariable and multivariable analyses with Cox proportional hazard model for survivorship and logistic regression for length of hospital stay more than 30 days were performed to identify significant prognostic factors including RDW, other laboratory results, demographic variables and co-morbidities. Results: RDW cut-off of 14.5% was found to be significantly associated with all-cause mortality (P < 0.001). High RDW was a significant risk factor or all-cause mortality (hazard ratio[HR]: 2.42, 95% confidence interval [CI]: 1.46 to 4.00) on multivariable- adjusted regression analysis. High RDW was also associated with longer hospitalization (odds ratio: 2.17, 95% CI: 1.29 to 3.66). Conclusion: High RDW over 14.5% value is an independent prognostic factor with increased mortality and prolonged hospital stay, implying that RDW may be a simple and inexpensive laboratory parameter for risk stratification in diabetic foot amputation.