Risk factor analysis for diabetic foot ulcer-related amputation including Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio.

Diabetic foot ulcer often leads to amputation, and both nutritional status and immune function have been associated with this process. We aimed to investigate the risk factors of diabetic ulcer-related amputation including the Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio biomarker. We evaluated data from hospital in patients with diabetic foot ulcer, performing univariate and multivariate analyses to screen for high-risk factors and Kaplan-Meier analysis to correlate high-risk factors with amputation-free survival. Overall, 389 patients underwent 247 amputations over the follow-up period. After correction to relevant variables, we identified five independent risk factors for diabetic ulcer-related amputation: ulcer severity, ulcer site, peripheral arterial disease, neutrophil-to-lymphocyte ratio and nutritional status. Amputation-free survival was lower for the moderate-to-severe versus mild cases, for the plantar forefoot versus hindfoot location, for the concomitant peripheral artery disease versus without and in the high versus low neutrophil-to-lymphocyte ratio (all p < 0.01). The results showed that ulcer severity (p < 0.01), ulcer site (p < 0.01), peripheral artery disease (p < 0.01), neutrophil-to-lymphocyte ratio (p < 0.01) and Controlling Nutritional Status score (p < 0.05) were independent risk factors for amputation in diabetic foot ulcer patients and have predictive values for diabetic foot ulcer progression to amputation.