A prospective cohort study on the joint associations of abdominal aortic calcification and systemic inflammation response index with mortality risk

Abdominal aortic calcification (AAC) and the systemic inflammation response index (SIRI) have been linked to both all-cause and cardiovascular disease (CVD)-related mortality. Whether combining AAC and SIRI improves the predictive ability for adverse outcomes remains poorly unexplored. The present study aims to investigate the joint associations of AAC and SIRI with the risk of all-cause and CVD-related mortality in the general population. This prospective cohort study included participants with AAC and SIRI data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES). Primary outcomes were death from any cause (all-cause mortality) and heart or cerebrovascular diseases (CVD-related mortality). AAC was categorized into three groups based on the AAC score: non-AAC (score = 0), low- moderate AAC (score > 0 and < 5), and severe AAC (score ≥ 5). SIRI ( x 10⁹/L) was stratified by tertiles. Multivariable Cox regression analyses and competing risk models were employed to examine the individual associations of AAC and SIRI with the risk of all-cause and CVD-related mortality. Participants were further divided into four groups according to AAC (presence or absence) and SIRI (≤ or > median) to explore their joint association. A total of 2159 participants with a median age of 55 years were included in this study. 1031 (47.8%) were males and 1128 (52.2%) were females. For race, 317 (14.7%) were mexican american, 226 (10.5%) were other hispanic, 878 (40.7%) were white, 431 (20.0%) were black, and 307 (14.2%) were other race. During a median of 73 months follow-up, 119 deaths were recorded, 41 of which were CVD-related cases. AAC was presented in 553 participants (355 with low-moderate AAC and 198 with severe AAC), and the median SIRI was 1.05 × 10⁹/L. After adjusting for potential confounding factors, AAC and SIRI were significantly associated with the risks of all-cause (AAC: HR_{severe AAC vs. non-AAC} = 2.903, 95% CI: 1.855 ~ 4.543, p for trend < 0.001; SIRI: HR_{tertile 3 vs. tertile 1} = 2.077, 95% CI: 1.264 ~ 3.411, p for trend = 0.001) and CVD-related death (AAC: HR_{severe AAC vs. non-AAC} = 4.579, 95% CI: 2.019 ~ 10.381, p for trend < 0.001; SIRI: HR_{tertile 3 vs. tertile 1} = 3.215, 95% CI: 1.253 ~ 8.246, p for trend = 0.006). These associations remained statistically significant even after mutual adjustment. Participants with both AAC presence and elevated SIRI had higher risk of adverse outcomes. Severe AAC and elevated SIRI were independently associated with an increased risk of all-cause and CVD-related mortality in the general population. Notably, individuals with both AAC presence and increased SIRI exhibited the greatest mortality risk. The combined assessment of AAC and SIRI may provide novel predictive value, offering a more comprehensive approach to identifying high-risk individuals and refining risk stratification strategies.