The epidemiology of subclavian artery calcification

Objectives: The purpose of the present study was to determine the prevalence and risk factor associations for subclavian artery calcification. Background: Arterial calcification is a marker of atherosclerosis, and its presence portends an adverse prognostic risk. The prevalence and associated risk factors for aortic arch, carotid, renal, and coronary calcification have been well described. Fewer data are available for subclavian artery calcification. Methods: Electron-beam computed tomography was used to evaluate the extent of vascular calcification in multiple arterial beds in 1387 consecutive individuals who presented for preventive medicine services at a university-affiliated disease prevention center. Laboratory values for blood pressure, lipids, anthropomorphic data, and self-reported medical history were obtained. Results: Subclavian artery calcification was present in 439 of 1387 individuals (31.7%). Those with subclavian artery calcification were significantly older, had a smaller body mass index, and were more likely to also have calcification of nonsubclavian vascular beds. When adjusted for cardiovascular disease risk factors, the presence of subclavian artery calcification was significantly associated with age (prevalence ratio [PR], 1.04; P < .001), hypertension (PR, 1.20; P = .01), history of smoking (PR, 1.21; P = .01), and calcification in nonsubclavian vascular beds (PR, 1.58; P = .01). Subclavian artery calcification was also associated with an increased pulse pressure (β-coefficient = 2.2, P = .008). Conclusions: Subclavian artery calcification is relatively common and is significantly associated with age, smoking, hypertension, and nonsubclavian vascular calcification. There may be a relationship between vascular stiffness, as manifested by a widened pulse pressure, and the presence of subclavian artery calcification.