Age is a major pathobiological determinant of aortic dilatation: a large autopsy study of community deaths.

Aim: Aortic dilatation is a well-known phenomenon in the elderly. We therefore aimed to study the pathobiological determinants of aortic dilatation. Methods: Retrospective chart review. The subjects were 833 consecutive autopsy cases (616 men and 217 women) of community deaths. The age at death ranged from 20 to 94 years, with an average of 59.2 years. We measured the internal circumference of the aortic root, arch, descending portion, abdominal portion, and bifurcation in unfixed opened aorta at the time of autopsy. Results: The simple correlation between age and aortic circumference was strongest for the descending portion, followed by the arch, abdominal portion, root, and bifurcation. The simple correlation coefficient reached 0.836 for the descending portion (p < 0.001). The circumference of the descending portion increased significantly as the severity of aortic atherosclerosis increased (p for trend < 0.001). Multiple regression analysis showed that age, sex, and body height were significantly correlated with the aortic circumference at all five measurement sites, while severe atherosclerosis was correlated with the aortic circumference at the root, and descending and abdominal portions. Six contributing factors (age, sex, body height, smoking history, hypertension, and severe atherosclerosis) explained 68.5% of the variance in circumference in the descending portion; age explained 57.5%; sex 8.4%; body height 1%; and severe atherosclerosis 0.8%. Conclusion: The contribution of atherosclerosis to aortic dilation was very weak, representing less than one seventieth of the contribution of age. The aortic circumference, especially in the descending portion, serves as an excellent age-related marker.