Abstract
BACKGROUND: The occurrence of abdominal aortic calcification (AAC) is associated with inflammation. This study aims to explore the relationship between the aggregate index of systemic inflammation (AISI) and AAC. METHODS: We utilized data from the 2013-2014 cycle of the National Health and Nutrition Examination Survey (NHANES). A loge transformation was applied to AISI (log(e)AISI) to preserve its normal distribution. Weighted multiple regression analysis, trend tests, smoothing curves, and threshold effect analysis were employed to evaluate the relationship between log(e)AISI and both AAC scores and severe AAC (SAAC). Subgroup analysis and interaction tests were conducted to evaluate the stability of their relationship across different populations. Additionally, receiver operating characteristic curves (ROC) were used to compare the predictive ability of log(e)AISI with systemic immune-inflammation index (SII), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR). RESULTS: This study included 2,730 participants. After adjusting for covariates, a positive correlation was observed between log(e)AISI and both AAC scores and SAAC. Compared to the first quartile of log(e)AISI, the highest quartile showed increased AAC scores (β = 0.37, 95% CI = 0.20-0.55) and a higher risk of SAAC (OR = 1.31, 95% CI = 1.06-1.62) in the fully adjusted model. Smooth curve and threshold effect analysis demonstrated a nonlinear relationship between log(e)AISI and both AAC scores and SAAC, with a breakpoint at 6.64. Subgroup analysis revealed that the relationship between log(e)AISI and AAC scores is more pronounced in individuals aged 65 and older, those with coronary artery disease, and diabetic patients, while the association with SAAC is more significant in diabetic patients. Compared to other inflammatory markers (SII, NLR, PLR), AISI has a higher predictive ability for AAC (AUC = 0.57, 95%CI: 0.54-0.59) and SAAC (AUC = 0.61, 95%CI: 0.58-0.65). CONCLUSION: Our study highlights that AISI is correlated with both AAC and SAAC. However, extensive prospective studies are required to validate our results.