The lymphocyte-eosinophil to neutrophil-monocyte ratio as a potential composite biomarker associated with asthma exacerbations in adults.

Background: This study evaluates the lymphocyte-eosinophil to neutrophil-monocyte ratio (LENMR) as a novel inflammatory indicator of the exacerbation risk in adults with asthma. Methods: This cross-sectional study included 1344 adults with asthma from the 2007-2012 cycles of the National Health and Nutrition Examination Survey. The association between LENMR and asthma exacerbations was evaluated by using multivariable logistic regression with progressive adjustment for confounders. Subgroup analyses were conducted to assess the consistency of associations. Restricted cubic spline and threshold effect models were used to explore potential nonlinear relationships. Results: A higher LENMR was significantly associated with an increased risk of asthma exacerbations. In the fully adjusted model, the participants in the highest quartile had a 77% higher odds of exacerbation compared with the lowest quartile (odds ratio 1.77 [95% confidence interval, 1.19-2.65]; p = 0.007). Associations were consistent across subgroups. Restricted cubic spline analysis revealed a significant nonlinear relationship, with a threshold effect identified at LENMR = 0.31. Conclusion: An elevated LENMR is positively associated with asthma exacerbations under specific thresholds.