Systemic immune-inflammation index and systemic inflammation response index as predictors of mortality in participants with and without cancer

ObjectiveThe objective of this study was to examine the associations of the systemic immune-inflammation index and the systemic inflammation response index with all-cause and cardiovascular mortality in cancer and noncancer populations.MethodsWe analyzed data from 42,503 adults in the National Health and Nutrition Examination Survey using Cox models and restricted cubic spline analyses.ResultsCompared with the lowest tertile, the highest systemic immune-inflammation index tertile was associated with increased risks of all-cause mortality (hazard ratio, 1.24; 95% confidence interval: 1.16-1.32) and cardiovascular mortality (hazard ratio, 1.29; 95% confidence interval: 1.15-1.45). The highest systemic inflammation response index tertile demonstrated similar increases in all-cause mortality (hazard ratio, 1.33; 95% confidence interval: 1.24-1.43) and cardiovascular mortality (hazard ratio, 1.42; 95% confidence interval: 1.25-1.61). Risks increased across tertiles, and dose-response patterns were supported by spline analyses. Estimates were greater among participants with cancer than among those without cancer.ConclusionsElevated levels of systemic immune-inflammation index and systemic inflammation response index were associated with increased risks of all-cause and cardiovascular mortality, particularly among participants with cancer, supporting their potential use as low-cost screening tools for risk stratification. Given the observational design and single baseline measurement, residual confounding and measurement error remain possible; prospective validation is warranted.