Renal artery calcium: relationship to systemic calcified atherosclerosis

Abstract

In this study we tested the hypothesis that calcium due to atherosclerosis in the renal arteries would be significantly associated with calcium in multiple other vascular beds, independent of traditional risk factors for cardiovascular disease (CVD). Electron beam computed tomography was conducted in 1461 consecutive asymptomatic patients free of clinical CVD to determine the presence and extent of calcium in the renal arteries, coronary and non-coronary vasculature and the aortic and mitral annuli. The overall prevalence for calcium in either renal artery was 18.0%, with men having a significantly higher prevalence (20.2%) than women (15.0%) [p = 0.01]. Renal artery calcium (RAC) was significantly correlated with calcium located in the carotids, coronaries, thoracic aorta, abdominal aorta and iliac arteries and calcium in the mitral and aortic annuli (r range = 0.22–0.37). In a multi-variable model containing the traditional CVD risk factors, the presence of calcium in the renal arteries was significantly associated with age, male sex and a diagnosis of hypertension. After adjustment for these variables, the presence of calcium in the thoracic or abdominal aorta was significantly associated with RAC (OR = 2.1 and 2.0, respectively; p < 0.01 for both). The sensitivity for prevalent RAC was highest in those individuals with any calcium in the abdominal aorta (94.5%). In conclusion, calcium related to atherosclerosis in the renal arteries is highly associated with atherosclerotic calcification in other vascular beds, especially the aorta, and the valvular annuli. These relationships are independent of traditional CVD risk factors.