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

•We investigated for the first time the relationship between Systemic Immune-Inflammation Index and abdominal aortic calcification.•Participants in the highest quartile of SII had a 47% higher risk of developing severe AAC than those in the lowest quartile.•The positive association between SII and AAC was more pronounced in the elderly, while it was not significant in those under 60 years of age.