Vertebrobasilar artery calcification: Prevalence and risk factors in the general population

Background and aims: Arteriosclerosis in the vertebrobasilar arteries may play an important role in the etiology of posterior circulation strokes, but little is known on its prevalence, its correlation with arteriosclerosis in other major arteries, and its risk factors. Hence, we investigated these aspects of vertebrobasilar artery calcification (VBAC) as marker of vertebrobasilar arteriosclerosis. Methods: To quantify VBAC, 2483 participants (mean age: 69.2 years, 52% female) from the Rotterdam Study underwent non-enhanced computed tomography. We determined the presence and volume of VBAC. Next, using Spearman's rank correlation, we examined the correlation between the volume of VBAC and the volume of coronary artery calcification (CAC), aortic arch calcification (AAC), and both extracranial-(ECAC), and intracranial carotid artery calcification (ICAC). Finally, we investigated associations of cardiovascular risk factors with the presence and volume of VBAC using logistic and linear regression models. Results: The overall prevalence of VBAC was 21.0% (median volume: 7.3 mm(3) [IQR: 2.0-25.6]). Correlations between VBAC and CAC, AAC, ECAC, and ICAC were weak to moderate (men: 0.33, 0.28, 0.30, 0.36; women: 0.26, 0.24, 0.24, 0.35, respectively). Hypertension, diabetes, and current smoking were associated with the presence of VBAC in both sexes (men: OR 1.67 [95%-CI, 1.14-2.46], 1.60 [95%-CI, 1.10-2.34], 1.48 [95%-CI, 1.02-2.14]; women: OR 1.51 [95%-CI, 1.01-2.26], 1.56 [95%-CI, 1.02-2.39], 1.53 [95%CI, 1.00-2.33], respectively). In men, obesity was also associated with VBAC (1.42 [95%-CI, 1.00-2.02]). Conclusions: VBAC occurs in over 20% of elderly community dwelling persons. Cardiovascular risk factors are associated with VBAC with similar patterns for men and women.