Prognostic Significance of Platelet-to-Lymphocyte and Neutrophil-to-Lymphocyte Ratios for Complications of Diabetic Foot Ulcers: A Meta-Analysis

One of the main consequences of diabetes mellitus is diabetic foot ulcers (DFUs), which often result in amputation and death. Two inflammatory biomarkers, platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR), measured in standard blood testing, have become potential indicators of many adverse outcomes in diabetes-related complications. However, evidence regarding their association with complications of DFUs remains limited and inconsistent. This study critically reviewed the prognostic value of both markers in predicting clinical consequences amongst patients with DFU. An inclusive literature search across PubMed, Web of Science, Embase, and ProQuest identified 22 relevant studies. Meta-analysis showed that NLR was associated with amputation (standardized mean difference (SMD) 0.78, p = 0.002) and osteomyelitis (SMD 0.31, p = 0.001). Similarly, PLR was associated with amputation (SMD 0.29, p = 0.005) and osteomyelitis (SMD 0.40, p < 0.001). Pooled diagnostic performance for mortality prediction showed good accuracy for NLR (area under the curve (AUC) 0.83) and moderate accuracy for PLR (AUC 0.75). Overall, both NLR and PLR are promising and readily available biomarkers for risk stratification in DFU patients. The results emphasize the necessity of standardized cut-off values and prospective validation.