Neutrophil-lymphocyte, platelets-lymphocyte and monocyte-lymphocyte ratios association with diabetes mellitus type 2 complications: a scoping review

Abstract

Noncommunicable diseases (NCDs) are a set of chronic conditions, which can generate functional disabilities. Type 2 diabetes mellitus (T2DM) is a NCD characterized by dysregulation of glucose use and insulin resistance, established nowadays as one of the main health problems in Brazil.  Low-grade inflammation, with prolonged release of inflammatory cytokines, has been related to the development of NCDs. In T2DM, chronic hyperglycemia leads to dysfunction in the eyes, kidneys, heart, and blood vessels. Markers of inflammation, such as neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), and platelet-to-lymphocyte (PLR) ratios, may contribute to the monitoring of NCDs patients. The objective of the present study was to perform a scoping review of the literature regarding the association of the ratios NLR, MLR and PLR and T2DM complications. Searches were carried out in PubMed, using pre-defined keywords/Mesh terms. Original articles or meta-analysis published in the last 10 years were included. Articles without abstracts, in languages other than Portuguese and English, and articles not available in full were excluded. Two researchers selected the articles blindly. A total of 40 studies were included. They had different designs, sample size, diagnostic criteria for T2DM, and were from different countries. Most have found a significant positive association of the ratios with nephropathy, retinopathy, and neuropathy, except for four studies with contradictory results. These markers have the advantage of being easily obtained from a complete blood count. Therefore, the results indicate that NLR, MLR, and PLR may be useful as prognostic markers, contributing to the management of T2DM patients.