Abstract

BACKGROUND Aortic dissection (AD) is a life-threatening emergency with high mortality. Although elevated body mass index (BMI) is associated with both AD incidence and mortality, the underlying mechanisms remain unclear. Periaortic adipose tissue (PAAT) increases with BMI, and the PAAT of AD shows marked inflammatory infiltration, suggesting PAAT-driven inflammation may contribute to the development of AD. However, no direct evidence links BMI and PAAT to AD. To further elucidate the obesity-inflammation-AD relationship, we aim to quantify the contributions of BMI, PAAT, and their derived indices to the risk of AD.

METHODS This retrospective multicenter study (June-November 2025) quantified PAAT around the descending thoracic aorta with CT angiography (CTA). Logistic regression analyses were performed to identify AD risk factors. Based on the Boruta algorithm (a machine learning feature selection method) and ROC curve analysis, the variable importance for AD risk was assessed. The dose–response relationship between BMI–Volume-derived metric (BMV) and AD risk was further characterized by quartile stratification and restricted cubic spline (RCS).

RESULTS This study enrolled 376 consecutive participants. After adjusting for potential confounders, BMI, smoking, systolic blood pressure (SBP), diabetes mellitus (DM), TC/HDLC, ApoE, PAAT volume (Volume), PAAT fat attenuation index (FAI), and BMV were identified as independent predictors of AD. Volume was the strongest AD predictor with the highest Z-score. Compared with BMI [AUC 0.627, 95% confidence interval (CI): 0.569–0.687] and Volume (AUC 0.716, 95% CI: 0.662–0.772), BMV showed better discriminatory performance (AUC 0.726, 95% CI: 0.673–0.778). RCS showed an approximately linear positive association between BMV and AD risk (P-overall < 0.001, P-non-linear = 0.09).

CONCLUSIONS In this retrospective multicenter study, BMV, a composite measure integrating systemic and periaortic adipose tissue factor, showed a positive association with AD risk, and improved predictive performance beyond BMI, indicating incremental predictive value, pending external validation.

GRAPHIC ABSTRACT A graphic abstract is available for this article.

WHAT IS KNOWN

Body-mass index (BMI) appears to be associated with an increased risk of aortic dissection (AD) and higher all-cause mortality, but a definitive consensus remains elusive.

PAAT has been identified as an independent cardiovascular risk factor, with marked inflammatory cell infiltration observed in the PAAT of PAAT has been identified as an independent cardiovascular risk factor, with marked inflammatory cell infiltration observed in the PAAT of aortic diseases patients.

PAAT increases with BMI, and its pro-inflammatory function may destabilize the aortic wall, but relationship of BMI–PAAT synergy and AD remains to be demonstrated.

WHAT THE STUDY ADDS

BMI, PAAT volume, and its FAI were independent predictors of AD, with volume ranked as the strongest predictor by the Boruta algorithm.

The BMV, a composite metric that integrated systemic and periaortic adipose tissue factor, was positively associated with AD risk and improved predictive performance beyond BMI alone.

Competing Interest Statement

The authors have declared no competing interest.

Clinical Trial

This is a retrospective study and trial registration is not applicable.

Funding Statement

This study was supported by the Noncommunicable Chronic Diseases-National Science and Technology Major Project (2024ZD0537800), National Natural Science Foundation of China (grant number: 82270415, and U24A20651), Shanghai Municipal Science and Technology Commission Fund (grant number: 20234Z00120 and 22S31904800), and Shanghai Sailing Program (grant number: 22QA1408600).We declare that the authors and their institutions have not received any payment or services from a third party for any aspect of this work.

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The Institutional Review Board of Chinese PLA General Hospital(S2023-597-01).

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I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

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Data Availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Non-standard Abbreviations and AcronymsPAATperivascular adipose tissueRCSrestricted cubic spline modelingBMVbody-mass-index-volume