To investigate the value of the miR-320b expression level in peripheral blood in evaluating the nature of carotid atherosclerotic plaque.

The 108 patients with carotid atherosclerosis admitted in Neurology Department of Bozhou People’s Hospital from May 2020 to September 2021 were set as the study group, and the 105 healthy volunteers in the same period were set as the control group. The expression levels of miR-320b in peripheral blood of the 2 groups were measured and compared. The patients in the study group were divided into plaque-free group and plaque group according to the results of carotid artery ultrasound examination, and the expression level of miR-320b was compared. In addition, according to the results of high resolution magnetic resonance imaging, the patients in the plaque group were divided into unstable plaque group and stable plaque group, and the miR-320b level in the this 2 groups was compared. The influencing factors of the nature of carotid atherosclerotic plaque and the evaluation effect of miR-320b level on unstable plaque of carotid atherosclerosis were analyzed.

The expression level of miR-320b in peripheral blood of the study group was lower than that of the control group (P<0.05). Compared with plaque-free group, the expression level of miR-320b in peripheral blood in the plaque group was significantly lower (P<0.05). The results of receiver operating characteristic (ROC) curve of miR-320b level in peripheral blood in evaluating carotid atherosclerotic plaque showed that the area under the curve (AUC) was 0.948, and the sensitivity and specificity were 88.24% and 97.30% respectively. The expression levels of miR-320b in peripheral blood of patients with carotid plaque type Ⅳ-Ⅴ and Ⅵ of American Heart Association (AHA) were lower than that of patients with type Ⅰ-Ⅱ, type Ⅲ, type Ⅶ and type Ⅷ, and the expression level of miR-320b in type Ⅵ patients was lower than that in type Ⅳ-Ⅴ patients, and the difference was statistically significant (P<0.05). Compared with the stable plaque group, the expression level of miR-320b in peripheral blood in the unstable plaque group was significantly lower (P<0.05). Multivariate logistic regression analysis showed that the levels of total cholesterol and low-density lipoprotein cholesterol were risk factors for unstable plaque of carotid atherosclerosis (OR=1.979, 2.217, P<0.05), but the high-density lipoprotein cholesterol and expression level of miR-320b in peripheral blood were protective factors for it (OR=0.641, 0.548, P<0.05). The ROC results of the expression level of miR-320b in peripheral blood in evaluating unstable plaques of carotid atherosclerotic showed that the AUC was 0.915, and the sensitivity and specificity were 76.47% and 92.50% respectively.

The expression level of miR-320b in peripheral blood may be related to the nature of carotid atherosclerotic plaque, which can better evaluate plaque instability.