Significance of Neutrophil to Lymphocyte Ratio (NLR) and Platelet Lymphocyte Ratio (PLR) in Diabetic Foot Ulcer and Potential New Therapeutic Targets

Diabetic foot ulcer (DFU) is a well-known complication of diabetes and a significant burden on the national health systems. The neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio are inexpensive and easily accessible biomarkers that have proved to be useful in several inflammatory, infectious and cardiovascular diseases. We carried out a comprehensive review examining the association of NLR and PLR with the onset and progression of DFU. PLR and NLR were significantly increased in patients with DFU, compared with a control group of T2DM patients without DFU, and correlate well with DFU severity, evaluated by Wagner and IWGDF grading scales. In patients with diabetic foot infections (DFI), elevated NLR and PLR were correlated with osteomyelitis, increased risk of amputation, and septic complications. The significance of the elevated value of these biomarkers in DFU is related to chronic hyperglycemia and low-grade systemic inflammation, atherosclerotic and vascular complications, and also the associated septic factor. Serial, dynamic follow-up can provide useful information in planning and monitoring DFU treatment, as well as in risk stratification of these vulnerable patients. Further randomized studies are needed to set the cut-off values with clinical significance.