Component analysis of HPLC profiles of unique lipoprotein subclass cholesterols for detection of coronary artery disease

Background: Patients with coronary artery disease (CAD) are known to have several lipoprotein abnormalities. We examined plasma cholesterol concentrations of major lipoproteins and their subclasses, using a gel permeation HPLC, to establish an association between a lipoprotein subclass pattern and the presence of CAD. Methods: We performed a simple and fully automated HPLC, followed by mathematical treatment on chromatograms, for measuring cholesterol concentrations of major lipoproteins and their subclasses in 62 male patients (45 with CAD and 17 controls without CAD) who underwent cardiac catheterization. Results: For major lipoprotein classes, the patient group had a significantly (P <0.05) higher LDL-cholesterol (LDL-C) and lower HDL-cholesterol (HDL-C), but no difference in VLDL-cholesterol (VLDL-C) concentrations. For lipoprotein subclasses, the patient group had a significantly higher small VLDL-C (mean particle diameter of 31.3 nm, P <0.001), small LDL-C (23.0 nm, P <0.05), and very small LDL-C (16.7-20.7 nm, P <0.001), but a significantly lower large HDL-C (12.1 nm, P <0.001) concentrations. Combined variables of "small VLDL-C + small LDL-C + very small LDL-C - large HDL-C″ differentiated the patient from the control group more clearly than single-subclass measurements or calculated traditional lipid markers. Conclusions: These results suggest the usefulness of multiple and simultaneous subclass analysis of proatherogenic and antiatherogenic lipoproteins and indicate that HPLC and its component analysis can be used for easy detection and evaluation of abnormal distribution of lipoprotein subclasses associated with CAD.