Ascending and descending thoracic aorta calcification in type 2 diabetes mellitus

Abstract

Background: Calcification of the thoracic aorta is a risk factor for cardiovascular disease and peripheral arterial disease but has not been well studied in diabetics. In addition, many studies consider aortic calcium as a single anatomic entity, whereas calcification of the ascending and descending portions of the thoracic aorta may represent separate phenotypes. We sought to characterize the prevalence of ascending and descending aortic calcium among diabetics and to assess their associations with cardiovascular risk factors, coronary artery calcium, and peripheral arterial disease.

Methods: Within the Penn Diabetes Heart Study, a cross-sectional study of subjects with type 2 diabetes mellitus but without coronary or renal disease, we quantified Agatston scores of the ascending and descending thoracic aorta in 1739 subjects (63% male, 61% Caucasian). Multivariate logistic and Tobit regressions were used to assess associations with cardiovascular risk factors, coronary calcium, and peripheral arterial disease.

Results: Of all subjects, 54% had thoracic aortic calcium; of these, 37% had calcium solely in the ascending thoracic aorta and 20% solely in the descending thoracic aorta. In multivariate regression, age, Caucasian race, systolic blood pressure, low-density lipoprotein cholesterol, smoking, and diabetes duration were independently associated with calcium of both the ascending and descending thoracic aorta (P < .001 for all). Ascending and descending aortic calcium were each independently associated with coronary calcium in multivariate regression, but only calcification of the descending thoracic aortic was associated with low ankle-brachial index.

Conclusion: Ascending and descending thoracic aortic calcium have similar associations with traditional cardiovascular risk factors in diabetics and are independently associated with coronary artery calcium. Only calcium in the descending aorta is associated with peripheral arterial disease. Delineation of both phenotypes may provide information about the individualized vascular disease and risk profile of patients with type 2 diabetes mellitus.

Keywords: Aorta; Arteriosclerosis; Calcium; Computed tomography; Diabetes mellitus type 2.