Abstract
The association between neutrophil-to-lymphocyte ratio (NLR), an inflammatory marker, and all-cause mortality among individuals with obstructive sleep apnea (OSA) remains unclear. This study aimed to evaluate the association of NLR with all-cause mortality among individuals with OSA. A total of 4,085 participants with OSA were selected from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2008, with follow-up data collected until December 31, 2019. Weighted Cox regression analyses were used to explore the association between the NLR and all-cause mortality. Nonlinear associations were detected using restricted cubic splines (RCS). Subgroup analyses were further performed to explore these relationships. The mean follow-up time for the entire cohort was 137.7 months. There was a clear trend of increasing mortality risk with higher NLR quartiles, rising from 11.86% in Q1, 13.41% in Q2, 14.81% in Q3, to 29.22% in Q4. The Cox regression analysis revealed that lnNLR was associated with an increased risk of all-cause mortality after full adjustment (hazard ratio [HR] = 1.81, 95% CI 1.43-2.30, p < 0.001). RCS showed a J-shaped relationship between lnNLR with all-cause mortality (p-non-linear < 0.001). The interaction tests found that coronary heart disease (CHD) influenced the association between lnNLR and all-cause mortality, with a HR of 3.98 for those with CHD and 1.62 for those without CHD (p = 0.008). There was a nonlinear correlation between elevated NLR and increased risk of all-cause mortality among OSA individuals. The association was more pronounced among CHD subgroups. Future research should explore the underlying mechanisms and evaluate whether therapies targeting inflammation can lower mortality risk in OSA patients.