Inflammation Levels and the Health Impact of Anti-Inflammatory Diets on Chronic Obstructive Pulmonary Disease: An NHANES Study

Background: Chronic obstructive pulmonary disease (COPD), the third leading cause of death globally, is closely associated with systemic inflammation in its pathophysiological mechanisms. Previous studies have primarily focused on localized airway inflammation, while the relationship between systemic inflammation markers such as the systemic immune-inflammation index (SII) and the systemic inflammation response index (SIRI)and COPD remains controversial. Additionally, the role of the composite dietary antioxidant index (CDAI) in modulating COPD risk requires further investigation. Methods: This cross-sectional study used data from NHANES (2007– 2012) to investigate the association between systemic inflammation levels and COPD prevalence. SII and SIRI levels were stratified by interquartile range (IQR). Generalized linear models (GLM) combined with logistic regression models were used to analyze the association between SII, SIRI, and COPD risk. Interaction analysis was used to evaluate the modulating effects of CDAI on inflammation levels and COPD risk. Results: A total of 8,601 participants were included in the study, among whom 881 were COPD patients. The analysis revealed that for each 1 IQR increase in SII and SIRI, the OR for COPD prevalence significantly increased by 1.28 (95% CI: 1.12– 1.47) and 1.45 (95% CI: 1.26– 1.67), respectively. Compared to the lowest SII group (Q1), the prevalence of COPD in the other groups increased by 1.01%, 1.43%, and 3.53%, respectively. Similarly, compared to the lowest SIRI group (Q1), the prevalence of COPD in the other groups increased by 1.54%, 4.08%, and 7.42%, respectively. In the low CDAI population, the risk of COPD associated with SII and SIRI was even higher, with ORs of 1.24 (95% CI: 1.01– 1.52) and 1.34 (95% CI: 1.09– 1.64), respectively. Conclusion: SII and SIRI, as systemic inflammation markers, are closely associated with the risk of COPD. Adjusting dietary patterns may have significant potential to slow the onset and progression of COPD. Keywords: COPD, inflammatory response, anti-inflammatory diet