C-reactive protein-to-lymphocyte ratio and stroke: associations with prevalence and subsequent mortality in NHANES 1999-2010.

Early risk detection is critical for timely intervention to reduce stroke morbidity and recurrence rate. This study systematically investigated the association between the CRP-to-lymphocyte ratio (CLR) and stroke prevalence, aiming to evaluate whether CLR may serve as a convenient and readily accessible inflammatory biomarker for stroke prediction. Data were analyzed from the 23,483 participants in the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2010. Multivariable logistic regression models were employed to assess the relationship between CLR and prevalent stroke. Among 789 individuals with a history of stroke, Cox proportional hazards models were used to examine the association between CLR and all-cause as well as cause-specific mortality. Kaplan-Meier survival curves were constructed to compare survival outcomes across CLR strata defined by an optimal cutoff. Restricted cubic spline (RCS) analysis was applied to explore potential nonlinear relationships. The predictive value of CLR was compared with that of established inflammatory markers using receiver operating characteristic (ROC) curve analysis. After adjusting for potential confounders, elevated CLR is significantly and independently associated with higher odds of stroke prevalence in the fully adjusted model (OR = 1.005, 95% CI: 1.002-1.007, P < 0.001). Kaplan-Meier analysis demonstrates significantly higher mortality risks among stroke participants with CLR above the optimal threshold. RCS models showed no evidence of nonlinearity between the CLR and mortality risks. Furthermore, ROC analysis indicated that CLR exhibited superior predictive ability compared to the established inflammation markers, including the Systemic Immune-Inflammation Index (SII), Neutrophil-to-Lymphocyte Ratio (NLR), C-reactive protein (CRP), and lymphocyte counts (all P < 0.05). These findings suggest that CLR is an independent and significant predictor of both the stroke prevalence and all-cause mortality in stroke patients, highlighting its potential utility as a readily accessible inflammatory biomarker for stroke prevalence stratification. Given its ease of derivation from routine examination data, CLR holds promise for broad clinical applicability. Further prospective studies are warranted to elucidate the underlying mechanisms and to validate its predictive value in diverse populations.Trial registration: This study is a secondary analysis of publicly available NHANES data and does not constitute a clinical trial; therefore, trial registration is not applicable.