Neutrophil-to-lymphocyte Ratio and Red Cell Distribution Width as Potential Biomarkers of Frailty: a Scoping Review

Background Frailty is associated with aging, which has recently become a health issue needs to be addressed urgently in the aging population. Neutrophil-to-lymphocyte ratio (NLR) and red cell distribution width (RDW) are novel inflammatory markers that are readily available clinically. Understanding the association of them with frailty is helpful to identify and monitor the development of frailty. There are few studies on the association of NLR and RDW with frailty, and they are not appropriate for traditional meta-analysis due to great heterogeneity between the study results. Objective To perform a scoping review of studies on NLR and RDW as potential biomarkers of frailty, so as to provide a reference for clarifying the pathogenesis of frailty and developing or improving frailty-related assessment tools. Methods Studies on the association of NLR and RDW with frailty were searched in eight databases (PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP and SinoMed) from inception to Marc