Systemic Immune-inflammation Index (SII) and Systemic Inflammatory Response Index (SIRI) as novel predictors of resistant hypertension

Aims: Resistant hypertension (RHT) accounts for 10-15% of hypertensive patients, and diagnosis and treatment are more complex in these cases, which means a higher risk of cardiovascular complications. Although the effect of chronic systemic inflammation on the pathophysiology of RHT is known, the effective use of biomarkers is limited. This study investigated the relationship between the Systemic Immune-Inflammation Index (SII) and the Systemic Inflammatory Response Index (SIRI), which are composite inflammatory indices that can be used as markers of chronic inflammation, and RHT, testing their clinical utility and predictive value. Methods: Between April 2022 and January 2025, 256 hypertensive patients followed up at our clinic were defined as having controlled hypertension (CHT) and 244 as having RHT, for a total of 500 patients included in this cross-sectional study. SII and SIRI values were calculated from routine blood count results. Data were analyzed and compared using multivariate logistic regression, quartile analysis, limited cubic spline modeling, and receiver operating characteristic (ROC) curve analysis. Results: Significantly higher SII (480.2 vs. 361.7, p