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.

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.

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 March 1, 2022. The studies on NLR and RDW as potential biomarkers of frailty was independently screened by two investigators, and the first author, publication time, country or region of publication, sample information, study methods, assessment tools, and assessment results were extracted. The quality of the literature was assessed using the Newcastle-Ottawa Scale and the AHRQ checklist for cross-sectional studies.

A total of fourteen studies were enrolled, including five cross-sectional studies, four longitudinal studies, one cohort study and four case-control studies, which were all rated≥4 points in terms of methodological quality, indicating that they were high quality. Nine studies examined the association between NLR and frailty, and seven of them showed that elevated NLR was independently associated with increased risk of frailty, and could predict its progression. Seven studies analyzed the association between RDW and frailty, and five of them showed that elevated RDW was independently associated with increased risk of frailty, and could predict its progression.

Some studies have shown that the risk of frailty increased with the elevation of NLR or RDW in different populations, and its progression could be predicted by NLR or RDW. As potential biomarkers of frailty, NLR and RDW could provide evidence for the pathogenesis of frailty, and a new theoretical basis for the development or improvement of frailty assessment tools. However, the optimal cut-off value of both for predicting frailty in different age groups and sex groups needs to be studied further.

衰弱作为衰老相关性疾病，近年来已成为老年人中一个亟待解决的健康问题。中性粒细胞与淋巴细胞比值（NLR）和红细胞分布宽度（RDW）是临床上易获取的新型炎性标志物，了解其水平变化与衰弱之间的关联，有助于识别并监测衰弱的发生、发展。然而目前NLR、RDW与衰弱的相关研究较少且存在较大异质性，不适合进行传统的Meta分析。

对NLR和RDW作为衰弱潜在生物标志物的相关研究进行范围综述，为明晰衰弱发病机制、开发或完善相关衰弱评估工具提供参考。

计算机检索PubMed、Embase、Cochrane Library、Web of Science、中国知网、万方数据知识服务平台、维普网和中国生物医学文献服务系统（SinoMed）共8个数据库，检索时限为建库至2022-03-01。由2名研究者独立筛选有关NLR和RDW作为衰弱潜在生物标志物的相关文献，并提取第一作者、发表时间、发表国家或地区、样本信息、研究方法、评估工具、评估结果。采用纽卡斯尔-渥太华量表、美国卫生保健质量和研究机构横断面研究评价标准进行文献质量评价。

共纳入14篇文献，其中横断面研究5篇、纵向研究4篇、队列研究1篇、病例对照研究4篇。14篇文献方法学质量评价得分均≥4分，纳入文献质量较高。共9项研究探讨了NLR与衰弱的关系，其中7项研究表明NLR与衰弱的发生风险及严重程度呈正相关，是衰弱发生的独立危险因素，并能预测衰弱的进展。共7项研究分析RDW与衰弱之间的关联，其中5项研究显示RDW与衰弱的发生风险及严重程度呈正相关，是衰弱发生的独立危险因素，并能预测衰弱的进展。

在不同人群中，部分研究显示NLR、RDW与衰弱的发生风险及严重程度呈正相关，是衰弱发生的独立危险因素，并能预测衰弱的进展。NLR、RDW作为衰弱潜在生物标志物，为衰弱发病机制提供额外证据，同时也为今后开发或完善衰弱评估工具提供新的理论基础。但关于二者对于不同年龄、性别人群的衰弱最佳预测值还需未来进一步探究。