Intracranial carotid artery atherosclerosis: prevalence and risk factors in the general population

Intracranial atherosclerosis is worldwide one of the leading causes of stroke. However, surprisingly little is known about its prevalence and risk factors in a community-dwelling population of white descent. In this study, we determined the prevalence and investigated risk factors of intracranial internal carotid artery calcification (ICAC) as a marker of intracranial atherosclerosis.

To quantify the volume of ICAC, 2495 participants (mean age, 69.6 years) from the population-based Rotterdam Study underwent a nonenhanced computed tomography of the intracranial internal carotid arteries. We calculated the prevalence of ICAC. Next, we defined sex-specific quartiles and defined the upper quartile as severe ICAC. Risk factors of ICAC were investigated by linear and logistic multivariate modeling and were stratified by sex.

The overall prevalence of ICAC was 82.2%. The median volume of ICAC was 44 mm3 and was larger in men. Age was independently associated with ICAC in both men and women. In men, excessive alcohol intake and smoking (OR, 1.74 [95% CI, 1.28-2.37] and 1.72 [95% CI, 1.10-2.70]) were strong risk factors of ICAC, whereas diabetes and hypertension were in women (OR, 2.02 [95% CI, 1.29-3.17] and 1.79 [95% CI, 1.20-2.68]). A low high-density-lipoprotein concentration was not associated with ICAC.

ICAC is highly prevalent and occurs in over 80% of older, white persons. Conventional cardiovascular risk factors are associated with ICAC, but risk factor profiles differ between men and women.