Association of neutrophil-to-lymphocyte ratio with stroke morbidity and mortality: evidence from the NHANES 1999-2020.

Background: Stroke is closely linked to inflammation, with the neutrophil-to-lymphocyte ratio (NLR) emerging as a promising inflammatory marker. This study aims to investigate the association between NLR and both morbidity and mortality in stroke patients. Methods: Data from the National Health and Nutrition Examination Survey (NHANES) 1999-2020 were analyzed, including adults with complete neutrophil and lymphocyte count records. Multivariate logistic regression was used to examine the relationship between NLR and both stroke morbidity and all-cause mortality. Restricted cubic spline regression was employed to assess potential nonlinearity in these associations. Subgroup analyses were performed to identify influencing factors. Results: After adjusting for confounders, the adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for stroke in the higher NLR quartiles, compared to the lowest quartile, were 1.28 (1.07-1.52) and 1.36 (1.12-1.65), respectively. The restricted cubic spline curve indicated a nonlinear positive association between NLR and stroke risk. Additionally, an elevated NLR was positively associated with an increased risk of all-cause mortality. Conclusion: The findings underscore the potential use of NLR in stratifying and predicting mortality risk in stroke patients, suggesting its relevance in clinical practice.