Systemic inflammation markers independently associated with increased mortality in individuals with hyperuricemia: Results from the NHANES prospective cohort study.

Background: Hyperuricemia is associated with increased systemic inflammation. The systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) are novel systemic inflammation markers and prognostic markers. However, no studies have evaluated the association between the SII/SIRI and mortality risk in individuals with hyperuricemia. This study aimed to investigate the predictive value of the SII and SIRI for all-cause and cardiovascular mortality in a large cohort of hyperuricemia patients.

Methods: We conducted a prospective cohort study using data from the National Health and Nutrition Examination Survey (NHANES) 2001-2020. Hyperuricemia was defined as serum uric acid (SUA) levels of ≥7 mg/dL in men and ≥6 mg/dL in women. The SII and SIRI were calculated based on complete blood count parameters. Associations with all-cause and cardiovascular mortality were analyzed using Cox proportional hazards models. Nonlinearity and effect modification were assessed using restricted cubic splines (RCS) and interaction analysis.

Results: Among the 6181 participants with hyperuricemia aged 20 years and older, over a total 181 months of follow-up, there were 936 all-cause deaths, of which 195 were cardiovascular mortality. In the fully adjusted models, the hazard ratios (HRs) were 1.73 (95% CI 1.42-2.13) for the SII and 2.18 (95% CI 1.82-2.62) for the SIRI with all-cause mortality. The adjusted HRs were 2.08 (95% CI 1.37-3.14) for the SII and 2.32 (95% CI 1.56-3.45) for the SIRI with cardiovascular mortality. Spline models identified nonlinear U-shaped (SII) and J-shaped (SIRI) relationships of inflammation markers with mortality.

Conclusions: Elevated SII and SIRI are independent predictors of mortality in hyperuricemia patients. These inflammatory biomarkers may improve risk stratification in this high-risk population. Further research should evaluate utility in guiding preventive interventions.