Association of Systemic Inflammation Response Index With All‐Cause and Cardiovascular Mortality Among Individuals With Depression: NHANES 2005–2018

BACKGROUND: The Systemic Inflammation Response Index (SIRI) has recently been investigated as a new marker of inflammation. This study investigated the association between SIRI and all-cause and cardiovascular mortality risks in patients with depression. METHODS: Based on data from the National Health and Nutrition Examination Survey (NHANES), 2410 participants with depression were included and followed up for all-cause and cardiovascular-related deaths through December 31, 2019. Depression was identified as a 9-item Patient Health Questionnaire (PHQ-9) score ≥10. Weighted multivariate Cox proportional hazards regression analyses assessed the relationship between SIRI and all-cause and cardiovascular mortality. Time-dependent receiver operating characteristic (ROC) curve analysis evaluated SIRI's accuracy in predicting survival outcomes. RESULTS: Among the 2410 participants, 282 all-cause death events and 84 cardiovascular disease (CVD)-related death events were documented. In the fully adjusted models, the highest SIRI tertile was significantly associated with increased risk of all-cause and cardiovascular mortality with hazard ratios (HRs) (95% CIs) of 1.26 (0.79, 2.02) for all-cause mortality and 2.50 (1.22, 5.13) for cardiovascular mortality. This association remained consistent in subgroup and sensitivity analyses. The time-dependent ROC curve showed that the areas under the curve of the 3-, 5-, and 10-year survival rates were 0.702, 0.692, and 0.644 for all-cause mortality, and 0.685, 0.714, and 0.653 for cardiovascular mortality, respectively. CONCLUSION: An elevated SIRI is associated with an increased risk of all-cause and cardiovascular mortality among patients with depression.