Abstract
BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) has been proposed as an inflammatory marker that might be associated with coronary atherosclerosis, although most of the current data is restricted to the acute setting. Additionally, the association of NLR with extracoronary atherosclerosis and stable disease remains unclear. OBJECTIVE: To analyze the association between NLR and abdominal aortic atherosclerosis (AAAt). METHODS: We included asymptomatic individuals who underwent a health screening program. AAAt was measured by ultrasound. Absolute leukocyte and lymphocyte counts were used to calculate the NLR. The level of significance for statistical analysis was 0.05. RESULTS: Among 36,985 individuals (age: 42±10 years, 72% male), AAAt was identified in 7%. Those with AAAt were older and more likely to be male and diabetic. Presence of AAAt was associated with increased NLR (odds ratio [OR] 1.17; 95% confidence interval [CI] 1.13-1.21). However, this association was no longer significant when the analysis was adjusted for risk factors (OR 1.02; 95% CI 0.97-1.06), mostly due to the inclusion of age in the model. When neutrophils and lymphocytes were analyzed separately, the negative association between lymphocytes and AAAt was inverted once age was accounted for, suggesting a strong confounding effect of age on the relationship between lymphocytes and atherosclerosis. Finally, the association of neutrophils and AAAt lost significance after an additional adjustment for traditional risk factors, but not age alone. CONCLUSION: Although the NLR was associated with AAAt, this was largely due to the confounding effect of age. Overall, the results suggest a limited role of leukocyte measurements as biomarkers of AAAt.