Associations between systemic immune-inflammation index and abdominal aortic calcification: Results of a nationwide survey

Background and aim The Systemic Immune-Inflammation Index (SII) is a novel index of inflammation assessment that appears to be superior to the common single blood index in the assessment of cardiovascular disease. The purpose of this study was to investigate the association between SII and abdominal aortic calcification (AAC) in adults. Methods and results Multivariate logistic regression, sensitivity analysis, and smoothing curve fitting were used to investigate the relationship between SII and AAC based on data from the National Health and Nutrition Examination Survey (NHANES) 2013–2014. Subgroup analysis and interaction tests were used to investigate whether this association was stable across populations. There was a positive association between SII and ACC in 3036 participants >40 years of age. In the fully adjusted model, each 100-unit increase in SII was associated with a 4% increase in the risk of developing severe AAC [1.04 (1.02, 1.07)]. Participants in the highest quartile of SII had a 47% higher risk of developing severe AAC than those in the lowest quartile [1.47 (1.10, 1.99)]. This positive association was more pronounced in older adults >60 years of age. Conclusions SII is positively associated with AAC in US adults. Our findings imply that SII has the potential to improve AAC prevention in the general population.