Relation between interleukin-6 level and subclinical intracranial large-artery atherosclerosis

Background The levels of systemic inflammatory markers have been shown to predict future cardiovascular events, but whether they are associated with intracranial large-artery atherosclerosis is uncertain. We investigated the relation between the level of inflammatory markers interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) and subclinical intracranial large-artery atherosclerosis in patients with risk factors for atherosclerosis. Methods Magnetic resonance angiography (MRA) was performed in 226 Japanese patients age range, 45–87 years without a history of cerebrovascular disease. Serum IL-6 and hsCRP and conventional risk factors for atherosclerosis were assessed. Results Forty-six patients (20.4%) were found by MRA to have one or more intracranial steno-occlusive lesions. Mean IL-6 levels were higher in patients with intracranial large-artery atherosclerosis than in those without. In addition, patients in the highest IL-6 tertile had higher unadjusted odds ratio (OR) for intracranial large-artery atherosclerosis than that of those in the lowest tertile (OR 3.25, 95% CI; 1.42–7.39). These associations were only slightly attenuated upon adjustment for conventional atherosclerotic risk factors and carotid intima-media thickness. Conclusions Increased levels of IL-6 appear to be associated with intracranial large-artery disease, suggesting a role for the inflammatory process in atherosclerosis of intracranial large arteries.