Background: The risk of coronary artery disease (CAD) increases two- to fourfold in diabetes. Small dense low-density lipoprotein (sdLDL) particles have been linked to an increased risk for CAD. In this study, we sought to compare the sdLDL cholesterol (sdLDL-C) level between the healthy control group and diabetics with CAD in the Taiwanese population.
Methods: Serum specimens were collected from healthy females and males of various age groups (n = 294), type 2 diabetics (DM) without complications (n = 113), and patients having DM with CAD (DM-CAD) (n = 46). The commercial kit was used for the measurement of sdLDL-C level, which employs a simpler method. After heparin-magnesium precipitation of lipoproteins with density <1.044 g/ml, sdLDL (density = 1.044-1.063 g/ml) remained in the supernatant and this sdLDL-C was measured using an automated chemistry analyzer.
Results: The sdLDL-C level was significantly higher in males than in females (p < 0.001) and there was an age effect on sdLDL-C (p < 0.001). The DM-CAD group had significantly higher sdLDL-C levels than the healthy control group (p < 0.001), but there was no statistical difference in the LDL-C level between DM-CAD group and the healthy control group. In addition, only individuals having both high LDL-C and sdLDL-C levels had a higher risk for DM-CAD, compared to those with low LDL-C levels and low sdLDL-C levels [Odds Ratio (OR) 4.97; 95% Confidence Interval (CI) 1.96-12.57; p = 0.001].
Conclusions: Our data suggest that the sdLDL-C level together with the LDL-C level are better risk assessment markers for type 2 diabetics with CAD than the LDL-C level alone.