Association of systemic immune-inflammation index and aggregate index of systemic inflammation with clinical status in stable and exacerbated COPD: A single-center retrospective study

Chronic obstructive pulmonary disease (COPD) is a condition characterized by persistent airflow limitation and inflammation. Exacerbations may occur even during the stable phase of COPD, which significantly affects patients' quality of life. This study investigates the association of the Systemic Immune-Inflammation Index (SII) and the Aggregate Index of Systemic Inflammation (AISI) with clinical status in COPD patients during stable and exacerbation phases. This retrospective study included 245 patients diagnosed with COPD between 2020 and 2025. The patients were divided into 2 groups: stable COPD (n = 120) and COPD exacerbation (n = 125). The demographic characteristics, pulmonary function tests, and biomarkers (SII, AISI) of the patients were retrospectively analyzed. Statistical significance level was accepted as P < .05. In the exacerbation group, the SII and AISI values were significantly higher compared to the stable group (SII: 2782.32 ± 439.56, AISI: 1242.6 ± 239.91, P < .001). A strong positive correlation was found between SII and AISI with hospital admission in the exacerbation group (SII: R = 0.824, AISI: R = 0.956, P < .001). In the ROC analysis performed to predict the exacerbation group, cutoff values of 688.8 for SII and 397.56 for AISI yielded AUC values of 0.962 and 0.938, respectively. Multivariate logistic regression analysis revealed that both SII (OR: 1.001, 95% CI: 1.000-1.002, P = .031) and AISI (OR: 1.003, 95% CI: 1.001-1.005, P = .002) serve as independent predictors of COPD exacerbation. SII and AISI are useful biomarkers associated with the clinical status of COPD patients in both stable and exacerbation phases. High SII and AISI values can accurately predict exacerbation and hospital admission risk, thus aiding in the more effective management of treatment processes.