A Body Shape Index and Aortic Disease-Related Mortality in Japanese General Population

Aortic diseases (ADs), including aortic dissection, aortic aneurysm, and aortic rupture, are fatal, with extremely high mortality rates. A body shape index (ABSI), an anthropometric measure calculated as waist circumference adjusted by height and weight, improves the predictive capacity for mortality. However, whether ABSI is a risk factor for AD-related mortality in the general population remains unclear.

We used a nationwide database of 630,842 individuals (aged 40-75 years) who participated in the annual "Specific Health Check and Guidance in Japan" between 2008 and 2010.

During the follow-up period of 3.8 years, 159 AD-related deaths occurred, including 105 aortic dissections and 54 aortic aneurysm ruptures. The subjects were divided into three groups based on ABSI tertiles. Kaplan-Meier analysis demonstrated that the 3^rd tertile (with the highest ABSI) had the greatest risk among the three groups. Multivariate Cox proportional hazard regression analysis demonstrated that ABSI was significantly associated with AD-related death after adjusting for confounding risk factors. Neither waist circumference nor body mass index consistently predicted AD-related death in the multivariate model. The prediction capacity was significantly improved by the addition of ABSI to the confounding risk factors.

We demonstrated for the first time that ABSI, a surrogate marker for abdominal visceral fat tissue, was associated with AD-related deaths in the general population, suggesting the importance of central adiposity in the development of AD.