Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio Predict Mortality in Patients with Diabetic Foot Ulcers Undergoing Amputations

• Main Authors: Chen W, Chen K, Xu Z, Hu Y, Liu Y, Liu W, Hu X, Ye T, Hong J, Zhu H, Shen F
• Format: Article
• Language: English
• Published: Dove Medical Press 2021-02-01
• Series: Diabetes, Metabolic Syndrome and Obesity : Targets and Therapy
• Subjects: amputation; platelet to lymphocyte ratio (plr); neutrophil to lymphocyte ratio (nlr); diabetic foot ulcer; mortality.
• Online Access: https://www.dovepress.com/neutrophil-to-lymphocyte-ratio-and-platelet-to-lymphocyte-ratio-predic-peer-reviewed-article-DMSO

Wenwen Chen,1,* Kun Chen,2,* Zhixiao Xu,3 Yepeng Hu,1 Yiying Liu,1 Wenyue Liu,1 Xiang Hu,1 Tingting Ye,1 Jing Hong,1 Hong Zhu,1 Feixia Shen1 1Department of Endocrinology and Metabolism, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People’s Republic of China; 2Department of Thoracic Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People’s Republic of China; 3Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Feixia ShenDepartment of Endocrinology and Metabolism, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, People’s Republic of ChinaEmail [e-mail]: Elevated platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) are associated with poor outcomes in various diseases. The objectives of this study were to explore the utility of PLR and NLR in predicting all-cause mortality in patients with diabetic foot ulcers (DFU) undergoing amputations.Patients and Methods: A retrospective observational study was performed that included a total of 348 DFU patients undergoing amputations. The primary end-point was all-cause death. According to the PLR and NLR cut-off values, patients were divided into two groups and Kaplan–Meier survival curves were constructed. Multivariable Cox regression was conducted to test the independent predictors of mortality in the study cohort.Results: All-cause mortality was significantly higher in patients with a high PLR/NLR compared to those with a low PLR/NLR. In the low NLR group, the overall survival (OS) rates at 1, 3, and 5 years after amputation were 96.8%, 84% and 80.1%, respectively (p=0.001). In the high NLR group the corresponding OS rates at 1, 3, and 5 years were 85.2%, 58.6% and 23.9% (p< 0.001). According to the multivariate analysis, age (HR 1.074, 95% CI 1.045– 1.104, p< 0.001), Wagner classification (HR 2.274, 95% CI 1.351– 3.828, p=0.002), PLR (HR 1.794, 95% CI 1.014– 3.174, p=0.045), NLR (HR 2.029, 95% CI 1.177– 3.499, p=0.011), creatinine (HR 1.003, 95% CI 1.001– 1.004, p< 0.001) and direct bilirubin (HR 1.154, 95% CI 1.081– 1.232, p< 0.001) were independent predictors of mortality following amputation.Conclusion: Postoperative PLR and NLR values may be reliable predictive biomarkers of mortality in patients following amputation for DFU. Considering the high mortality in those patients, the patients with elevated PLR/NLR should be given more intensive in clinical practice.Keywords: amputation, platelet-to-lymphocyte ratio, PLR, neutrophil-to-lymphocyte ratio, NLR, diabetic foot ulcer, mortality