RESUMO
Objective To explore the association between carotid artery plaque and small dense low-density lipoprotein cholesterol(sdLDL-C)concentrations as well as the probability of sdLDL-C and sdLDL-C/LDL-C ratio as biomarkers of human carotid atherosclerotic plaque.Methods 174 subjects in physical examination center of An Zhen Hospital from November 2015 to February 2016 were enrolled one by one as a cross-sectional study.All subjects were divided into carotid IMT abnormal group(n=92)and control group(n=82)according to carotid ultrasound.According to the thickness of IMT characterized by carotid ultrasound,subjects were divided into the thickened IMT group(n=32), plaques group(n=60), and plaques group were divided into single plaque group(n=33)and multiple plaques group(n=27).Body Mass Index(BMI), fasting serum sdLDL-C, triglyceride(TG), LDL-C and high-density lipoprotein cholesterol(HDL-C)concentrations were measured.Pearson′s and Spearman correlation coefficient analyses and logistic regression analyses were used to examine the relationships between carotid atherosclerotic plaque,sdLDL-C values,and other clinical variables.Area under curve(AUC)was calculated to determine the diagnostic value of sdLDL-C and sdLDL-C/LDL-C ratio in subjects with carotid atherosclerotic plaque. Results Levels of sdLDL-C(1.02 ±0.42 vs.0.97 ±0.46 vs.0.61 ±0.29, F=21.07, P<0.001)and sdLDL-C /LDL-C(0.34 ±0.17 vs.0.34 ±0.17 vs.0.21 ±0.09,F=16.34,P<0.001)in the thickened IMT group and the plaques group were higher than those of the control group).Even in individuals considered to be at low LDL-C(<2.59 mmol/L)level,sdLDL-C(0.94 ±0.41 vs.0.56 ±0.25,t=4.00, P<0.01)and sdLDL-C/LDL-C ratio(0.43 ±0.19 vs.0.24 ±0.08,t=4.45,P<0.01)remained higher in the carotid abnormal group than those in the control group.Age and sdLDL-C were the independent risk factors of carotid artery plaque.AUC of receiver operator characteristic curve(ROC)for serum sdLDL-C and sdLDL-C/LDL-C ratio were 0.882(95% CI:0.819-0.945, P<0.01)and 0.830(95% CI:0.747-0.914,P<0.01)to determine the multiple carotid atherosclerotic plaque,and the cut-off level were 0.90 mmol/L(sensitivity,88.0%;specificity,79.3%)and 0.30(sensitivity,84.0%;specificity,74.5%). Conclusions Carotid atherosclerotic plaque has a close relationship with sdLDL-C concentrations.sdLDL-C and sdLDL-C/LDL-C ratio can be biomarkers when assessing subjects with a carotid atherosclerotic plaque.