Abstract
OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease characterized by increased inflammation, persistent decline in lung function, and extensive lung damage. Research has shown that inflammation plays a crucial role in the formation and progression of COPD. The systemic inflammation response index (SIRI) is an emerging inflammatory biomarker whose clinical significance in COPD remains undetermined. This study aims to explore the potential association between serum inflammatory marker SIRI levels and the prevalence of COPD. METHODS: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) database from 2013-2018. A total of 10,273 participants were analyzed and divided into two groups: COPD (n = 595) and non-COPD (n = 9678). Comparative analysis of demographic and clinical characteristics was performed between cohorts. The SIRI was calculated based on the counts of monocytes, neutrophils, and lymphocytes. Weighted logistic regression models were applied to assess the association between SIRI and COPD, while restricted cubic spline (RCS) curves were utilized to investigate potential non-linear relationships. Additionally, subgroup and interaction analyses were performed. RESULTS: Our study included 10,273 participants, of whom 595 were diagnosed with COPD, while 9678 were diagnosed with non-COPD. In the fully adjusted logistic regression model, SIRI was significantly positively correlated with COPD (OR = 1.96, 95% CI = 1.34-2.87). The analysis of the RCS curve revealed a non-linear relationship between SIRI and COPD (P < 0.05). Subgroup and interaction analyses further confirmed the robustness of our findings. CONCLUSION: Serum inflammatory marker SIRI levels are positively correlated with the occurrence of COPD and exhibit a non-linear relationship.