Abstract P127: Systemic Immune-Inflammatory Index (SII) in Hypertensive Adults

Aside from age, hypertension is the most predominant cardiovascular disease risk factor worldwide. In the United States, ~45% of the adult population have blood pressure higher than 130/80 mmHg. Hypertension is associated with increased risk of myocardial infarction, heart failure, stroke and vascular disease. Systemic immune-inflammation index (SII) is a novel biomarker of systemic inflammation and immunity. Clinical interest in SII has intensified due to its association with major cardiovascular events and prognostic value in cardiovascular outcomes. Indeed, the index has been shown to be a strong prognostic marker for coronary artery disease, heart failure, cardiac death and stroke. It is currently unknown whether SII is elevated in adults with elevated blood pressure. We tested the hypothesis that hypertension is associated with an elevated SII, independent of other cardiometabolic risk factors and/or disease. Fifty-six adults (age range: 43 to 66 years) were studied: 22 normotensive (NT: 10M/12F; age 57 + 1 yr; BMI: 27.7 + 1.0 kg/m 2 ; BP: 120/75 + 1/1 mmHg) and 34 hypertensive (HT: 23M/11F; age 57 + 1 yr; 28.4 + 0.6 kg/m 2 ; BP 140/85 + 1/1 mmHg). All subjects were sedentary, non-smokers, normolipidemic, normoglycemic, non-medicated, and free of overt cardiometabolic diseases. SII was calculated as total peripheral platelets count x neutrophil-to-lymphocyte ratio. SII was significantly higher (~20%) in the HT (479.6 + 25.0) vs NT (402.5 + 27.8) group. There was no significant sex by blood pressure interaction with SII. SII was similar and equally elevated in HT males (487.7 + 34.7) and females (462.7 + 28.7) than NT males (364.4 + 30.8) and females (425.9 + 39.9). SII was independently associated with systolic (r=0.30; P<0.05) and mean arterial (r=0.26; P<0.05) blood pressure; SII was not significantly associated with any other anthropometric, hemodynamic or metabolic variable. Hypertension is associated with elevated SII indicative of greater systemic immune-inflammatory activation. Increased immune activation and inflammatory burden contribute not only to atherosclerosis but to progression of hypertension. Given the link between SII and poor prognosis, SII may aid in identifying high risk hypertensive groups.