Abstract:Aim To investigate the correlation between serum remnant lipoprotein cholesterol(RLP-C), triglyceride levels(TG) and coronary heart disease(CHD) in middle-aged people. Methods A total of 439 middle-aged individuals who were hospitalized in the Department of Cardiology of Liuzhou People's Hospital from January 2015 to December 2022 and underwent coronary angiography were selected as the research subjects. They were divided into CHD group (190 cases) and control group (249 cases) according to the results of coronary angiography. The general clinical data and laboratory tests of the subjects were collected,and RLP-C was calculated based on blood lipid profile. Bivariate Spearman correlation, multivariate Logistic regression, and restricted cubic spline graph were used to analyze the correlation between RLP-C, TG, and CHD in these middle-aged participants. Receiver operating characteristic (ROC) curve was used to evaluate the value of RLP-C and TG in predicting CHD. Results The age in CHD group was older than that in control group, proportion of male, proportion of smoking history, incidence of hypertension, incidence of diabetes, incidence of hyperlipidemia, body mass index (BMI), systolic blood pressure(SBP), fasting blood glucose (FBG), glycosylated hemoglobin (HbA1c), TG, low density lipoprotein cholesterol (LDLC), RLP-C were higher than those in control group, while high density lipoprotein cholesterol (HDLC) was lower than that in control group (P<0.05). The Spearman correlation analysis results showed positive correlation between RLP-C, TG, LDLC and CHD (r=0.7,0.279, and 0.105, respectively, P<0.05), and negative correlation between HDLC and CHD (r=-0.340, P<0.001) in these studied population. Multivariate Logistic regression analysis showed that whether as continuous or categorical variables, RLP-C and TG were independent risk factors for CHD (P<0.05), HDLC was independent protective factor for CHD (P<0.05). Compared with lowest quartile group, The OR (95%CI) of CHD incidence in 3rd and 4th quartile group of RLP-C were 2.648(1.364~5.144) and 2.847(1.468~5.520) respectively; The OR (95%CI) of CHD incidence in 3rd and 4th quartile group of TG were 3.043(1.520~6.092) and 3.520(1.811~6.842) respectively. The restricted cubic spline graph revealed that RLP-C, TG were positively nonlinearly correlated with CHD (P for overall<0.001, P for nonlinear=0.2,0.001, respectively). Subgroup analysis showed that the relationship between RLP-C, TG and CHD was more significant in females than in males. ROC curve analysis showed that the areas under the curve (95%CI) of RLP-C, TG in predicting CHD were 0.632(0.580~0.685) (P<0.001) and 0.663(0.612~0.713) (P<0.001) in general, meanwhile, 0.735(0.659~0.811) (P<0.001) and 0.740(0.666~0.813) (P<0.001) in females. Conclusion RLP-C and TG are independent risk factors for CHD in middle-aged people, and their correlation with CHD are greater than that of LDLC. They may become the main targets for the prevention and treatment of CHD, and should be given clinical attention.