AIM To explore the correlation between serum bilirubin levels and the vulnerability of carotid plaque in healthy population.

METHODS The data of patients with carotid plaque detected during health examination in our hospital from May 2020 to Dec 2020 were collected and the plaques were divided into stable plaque and vulnerable plaque according to cervical duplex ultrasound. The patients in the two groups were matched with age, gender, BMI, systolic blood pressure, diastolic blood pressure, coronary heart disease, hypertension, diabetes and smoking history, etc. Finally, 205 patients with stable plaques and 569 with vulnerable plaques were included for inter-group comparison and logistic regression analysis. RESULTES After propensity score matching, there was no statistical difference between the two groups in coronary heart disease, hypertension, diabetes, fatty liver, family history and smoking history. The serum total cholesterol and low-density lipoprotein levels in the vulnerable plaque group were higher than those in the stable plaque group, while direct bilirubin levels were significantly reduced (all P<0.05). The results of logistic regression analysis suggest that a decrease in serum direct bilirubin levels may be an independent risk factor for increased vulnerability of cervical plaques (B=−0.013, OR=0.893, 95% CI: 0.819～0.974).

CONCLUSION The decrease of serum direct bilirubin is associated with the increased vulnerability of carotid plaque, which may be an early risk factor for atherosclerosis.