A Comparative Analysis of Serum Apolipoprotein Profiles and Lipoprotein(a) in Type 2 Diabetic Patients With Coronary Heart Disease

ABSTRACT Traditional lipid parameters poorly capture coronary heart disease (CHD) risk in type 2 diabetes mellitus (T2DM). This study compared apolipoprotein (ApoA1, ApoB) and lipoprotein(a) [Lp(a)] profiles between T2DM patients with and without CHD and evaluated their combined predictive value. This retrospective study included 140 T2DM patients, 70 with angiographically confirmed CHD and 70 age‐ and sex‐matched without CHD (defined by the absence of cardiac symptoms, normal electrocardiogram, and normal echocardiogram). Fasting serum levels of traditional lipids, ApoA1, ApoB, and Lp(a) were measured, and the ApoB/ApoA1 ratio was calculated. Multivariate logistic regression and ROC curve analysis identified independent predictors and assessed predictive performance. Traditional lipid parameters showed no significant differences between groups (all p > 0.05). CHD patients had significantly lower ApoA1 (1.33 vs. 1.56 g/L, p < 0.001) and higher ApoB (1.40 vs. 1.21 g/L, p < 0.001), ApoB/ApoA1 ratio (1.05 vs. 0.78, p < 0.001), and Lp(a) (20.65 vs. 14.10 mg/dL, p = 0.009). Multivariate analysis identified smoking, ApoB/ApoA1 ratio, and Lp(a) as independent predictors. The ApoB/ApoA1 ratio yielded an AUC of 0.912. A combined model achieved an AUC of 0.976, with bootstrap internal validation confirming robustness (optimism‐corrected AUC = 0.959, 95% CI: 0.921–0.982). The ApoB/ApoA1 ratio and Lp(a) were independently associated with CHD in T2DM patients. The combined model demonstrated excellent predictive performance, maintained after internal validation, though external validation is needed.