Objective:

To systematically evaluate the associations of Systemic Immune-Inflammation Index (SII) and Systemic Inflammatory Response Index (SIRI) with chronic obstructive pulmonary disease (COPD) prevalence and prognosis.

Approach:

• Literature Search: Systematic search of PubMed, Embase, Web of Science, and Cochrane Library for observational studies on SII and SIRI related to COPD risk, all-cause mortality (ACM), or respiratory failure (RF) up to March 23, 2023.

Key Findings:

• Elevated SII is significantly associated with higher prevalence of COPD (OR = 1.22, 95% CI: 1.06–1.41), higher ACM (OR = 1.20, 95% CI: 1.09–1.36), and higher risk of RF (OR = 1.61, 95% CI: 1.28–2.02).
• No significant association was found between SIRI and COPD risk (OR = 1.14, 95% CI: 0.90–1.45).
• Subgroup analyses indicated non-significant association of SII with COPD risk in certain populations.

Interpretation:

SII is a promising biomarker for assessing COPD prevalence, ACM, and RF, while SIRI does not show a significant association.

Limitations:

• The study is based on observational studies, which may introduce bias, including selection and confounding bias.
• Subgroup analyses may limit generalizability of findings.

Conclusion:

SII is an easily measurable biomarker associated with COPD outcomes, warranting further studies to establish cutoff values and validate clinical utility.