Association between red blood cell distribution width-to-albumin ratio and risk of low lean mass: A cross-sectional study of NHANES 1999-2018.

ObjectivesLow lean mass (LLM), as a critical element of sarcopenia, is associated with chronic inflammation and malnutrition and presents substantial risks to ageing populations. Although the red blood cell distribution width-to-albumin ratio (RAR) has been identified as a promising biomarker in various inflammatory and nutritional contexts, its relationship with LLM has not yet been investigated. This study seeks to examine the association between RAR and the risk of LLM.MethodsA cross-sectional analysis was conducted using data from 22,299 adults participating in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. LLM was defined according to the criteria established by the Foundation for the National Institutes of Health. Multivariable logistic regression and restricted cubic spline models were employed to assess the relationship between RAR and LLM, adjusting for variables including age, gender, marital status, race and ethnicity, body mass index, smoking status, alcohol consumption, educational attainment, diabetes mellitus, cardiovascular disease, moderate-to-vigorous physical activity, and time spent in sedentary activities. Subgroup analyses and propensity score matching analyses were also conducted.ResultsThe prevalence of LLM was 10.3% in NHANES 1999-2018. Restricted cubic splines analysis revealed a significant dose-response relationship between RAR and LLM risk (P < .001). Based on multivariate logistic regression, elevated RAR levels were linked to a higher odds of LLM (OR 1.84, 95% CI 1.64-2.06, P < .001). Specifically, individuals in the highest RAR quartile (Q4) had an OR of 2.38 (95% CI 2.00-2.83, P < .001) for developing LLM compared to those in the lowest quartile (Q1). Sensitivity analysis confirmed the robustness of this positive association in several subgroup analyses and propensity score matching analysis.ConclusionHigh RAR is associated with higher odds of LLM risk in community populations. These findings serve as a basis for further research on sarcopenia and need thorough validation in various populations.