Systemic immune-inflammation index: a novel tool for hypertension management in primary care.
Level 4 - case-series / case-control
Retrospective case-control study
PubMed 41840494 · doi:10.1186/s12875-026-03276-8
What was done
A retrospective case-control study evaluated 655 hypertensive patients and 669 healthy controls aged 18 years or older. Individuals with acute or chronic infections, malignancy, autoimmune, or rheumatologic diseases were excluded. The systemic immune-inflammation index (SII) was calculated from routine complete blood counts (platelet × neutrophil / lymphocyte). Group differences, diagnostic accuracy, and associations were evaluated using the Mann-Whitney U test, receiver operating characteristic (ROC) curve analysis, and multivariate logistic regression.
What was found
Median SII was significantly higher in hypertensive patients compared with healthy controls (536.9 vs. 381.3, p < 0.0001). ROC analysis identified an optimal SII cut-off value of 520.45 for identifying hypertension (AUC = 0.73, 95% CI: 0.70-0.76), with 52.4% sensitivity and 83.6% specificity. Individuals with SII > 520.45 had 7.3-fold higher odds of hypertension compared to the reference group with SII <= 520.45 (OR = 0.137, B = -1.986, 95% CI: 0.099-0.191, p < 0.0001). SII levels were significantly higher in newly diagnosed hypertensive patients compared with previously diagnosed patients (p < 0.001). There was no significant difference in SII values between hypertensive patients with and without comorbidities (p = 0.596).
Why it matters
The study demonstrates that SII, a low-cost marker calculated from routine complete blood counts, is elevated in hypertension and may provide adjunctive value for risk stratification in primary care.
Limits
The retrospective case-control design precludes causal inference. Sensitivity was low at 52.4%, limiting utility as a standalone screening tool. The abstract does not report antihypertensive medications, lifestyle confounders, or longitudinal follow-up.
Cited by
- contradicts The systemic immune-inflammation index is calculated from neutrophil, lymphocyte, and platelet counts on a standard complete blood count, and a score above 2 indicates an inflammatory state.