High neutrophil to lymphocyte ratios predict intracranial atherosclerosis in a healthy population

Although atherosclerosis has been shown to be an inflammatory disease, intracranial atherosclerosis (ICAS) has not been well addressed. The purpose of this study was to evaluate the relationship between the neutrophil to lymphocyte ratio (NLR) and the presence of ICAS lesions in a generally healthy population.

A consecutive series of subjects, who voluntarily visited for health check-ups between January 2006 and December 2013, were selected. Brain magnetic resonance imaging, brain magnetic angiography (MRA), and blood cell count data were assessed. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels, as observed on brain MRA images. NLR was calculated based on absolute neutrophil and lymphocyte counts.

A total of 2842 subjects were evaluated, and 76 ICAS cases were found. The median NLR was 1.52 [1.17-2.01]. In multivariate analysis, NLR remained an independent predictor of ICAS [adjusted OR (aOR) = 1.72, 95% confidence interval (CI) = 1.01-2.95, p = 0.048]. Age (aOR = 1.08, 95% CI = 1.05-1.11, p < 0.001) and hypertension (aOR = 1.81, 95% CI = 1.11-2.94, p = 0.017) were also significant factors for ICAS independent of NLR. Regarding ICAS burdens, NLR was significantly higher when the number of ICAS lesions (p = 0.017) or occlusive ICAS lesions (p = 0.005) was increased in a dose-response manner.

A high NLR was associated with both prevalence and burdens of ICAS in a healthy population.