Inflammatory indexes are not associated with sarcopenia in Chinese community-dwelling older people: a cross-sectional study

BACKGROUND: Inflammatory indexes (platelet-to-lymphocyte ratio [PLR], neutrophil-to-lymphocyte ratio [NLR], and lymphocyte-to-monocyte ratio [LMR]) are recently supposed to be the biomarkers of sarcopenia. We aimed to validate the association between these inflammatory indexes and sarcopenia in Chinese community-dwelling older people. METHODS: We consecutively recruited community-dwelling older adults aged 60 years or older. The neutrophil, lymphocyte, monocyte, and platelet counts, and C-reactive protein (CRP) were tested using standard methods. Sarcopenia was defined according to different criteria: the Asian Working Group for Sarcopenia (AWGS), the updated version of AWGS (AWGS 2019), the European Working Group on Sarcopenia in Older People (EWGSOP), the updated version of EWGSOP (EWGSOP2), the International Working Group on Sarcopenia (IWGS), and the Foundation for the National Institutes of Health Sarcopenia Project (FNIH). Multiple logistic regression analysis was performed. RESULTS: We included 384 participants. A total of 61 participants (15.9%) were diagnosed with sarcopenia according to the AWGS criteria. There was no significant difference in PLR, NLR, LMR, and CRP between the sarcopenia group and the non-sarcopenia group regardless of the diagnostic criteria. No significant association between PLR, NLR, LMR, and AWGS-defined sarcopenia was found (PLR per 1- standard deviation [SD]: adjusted odds ratio [OR] 1.09, 95% confidence interval [CI] 0.82 to 1.45; NLR per 1-SD: adjusted OR 0.96, 95% CI 0.71 to 1.30; LMR per 1-SD: adjusted OR 1.01, 95% CI 0.74 to 1.38). Similar results were found when sarcopenia was defined by different criteria and when PLR, NLR, LMR were treated as categorical variables. CONCLUSIONS: Our study did not support the utility of the inflammatory indexes (NLR, PLR, and LMR) as the biomarkers of sarcopenia in Chinese community-dwelling older people. However, considering the inflammatory indexes can be simply calculated from a routine blood test, further studies in different populations remain warranted. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12877-020-01857-5.