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The following is a summary of “Association of eosinophil-to-monocyte ratio with asthma exacerbations in adults: a cross-sectional analysis of NHANES data,” published in the April 2025 issue of the BMC Pulmonary Medicine by Xie et al.

The eosinophil-to-monocyte ratio (EMR) has gained recognition as a promising inflammatory biomarker across a spectrum of chronic and immune-mediated conditions. This study aimed to evaluate the predictive utility of EMR in identifying individuals at increased risk of asthma exacerbations within a nationally representative population.A cross-sectional analysis was conducted using data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 1999 to 2020. A total of 4,738 adults with physician-diagnosed asthma were included in the final sample. To ensure population-level generalizability, all analyses incorporated NHANES sample weights. The association between EMR and asthma exacerbations—defined by clinical history and patient-reported outcomes—was assessed using multivariable logistic regression models. These models were progressively adjusted for a range of potential confounding factors, including demographic characteristics, socioeconomic status, lifestyle behaviors, and comorbid conditions. Subgroup analyses were performed by stratifying participants based on age, sex, smoking status, and other clinically relevant variables to identify potential effect modifiers. In addition, RCS modeling was utilized to examine potential non-linear associations between EMR and exacerbation risk. Sensitivity analyses further tested the robustness of the observed associations.

Higher EMR levels were significantly correlated with an increased likelihood of experiencing asthma exacerbations. Across all three adjusted logistic regression models, the association remained statistically significant (p < 0.001). Specifically, participants in the highest quartile of EMR (Q4) demonstrated a 54% higher odds of exacerbation compared to those in the lowest quartile in Model 1 (OR: 1.54; 95% CI: 1.23–1.93). This association was further strengthened in Model 2 (OR: 1.56; 95% CI: 1.24–1.97) and Model 3 (OR: 1.58; 95% CI: 1.24–2.02), following additional covariate adjustments. Subgroup analyses consistently confirmed the relationship between elevated EMR and exacerbation risk across various strata, with no statistically significant interaction effects (all p for interaction > 0.05). Moreover, RCS analysis demonstrated a linear dose-response relationship between EMR and asthma exacerbations, with no evidence of a threshold or non-linear inflection point (p for non-linearity > 0.05). The results of sensitivity analyses supported the stability and reliability of these findings.

This study provides compelling evidence that EMR is an independent and reliable biomarker associated with an increased risk of asthma exacerbations in adults. The linear relationship between EMR and exacerbation risk, coupled with consistent findings across subgroups, highlights its potential clinical utility in asthma risk stratification and personalized disease management. Future longitudinal and interventional studies are warranted to validate these findings and explore the mechanisms linking elevated EMR to asthma pathophysiology.

Source: bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-025-03617-w