Objectives: Some normocholesterolemic patients have coronary artery disease (CAD) in Japan. This study evaluated the clinical significance of preheparin lipoprotein lipase mass as a risk factor for normocholesterolemic patients with CAD.
Methods: This study included 89 normocholesterolemic male patients with CAD (CAD group, 40 with stable organic angina pectoris, 19 with vasospastic angina pectoris, and 30 with acute myocardial infarction), and 13 normocholesterolemic males with normal coronary arteries (control group) with no stenotic lesion and negative reaction to intracoronary administration of acetylcholine. Preheparin lipoprotein lipase mass was measured by enzyme-linked immunosorbent assay. Coronary risk factors including preheparin lipoprotein lipase mass were compared between the two groups. Low-density lipoprotein (LDL) particle size and presence of midband were estimated by polyacrylamide gel disc electrophoresis.
Results: Mild hypertriglyceridemia and low high-density lipoprotein (HDL) cholesterolemia were observed in the CAD group, and small particle size LDL and presence of midband were also common in the CAD group. Preheparin lipoprotein lipase mass level was significantly lower in the CAD group than the control group (52 +/- 18 vs 40 +/- 13 ng/ml, p = 0.005) as well as in each type of patient in the CAD group. Multiple regression analysis showed that small particle size LDL, low preheparin lipoprotein lipase mass and smoking were independent risk factors for CAD (p < 0.001, p = 0.007, p = 0.037). Low preheparin lipoprotein lipase mass concentration was observed in the small particle size LDL group and/or the midband positive group.
Conclusions: These results indicate that low preheparin lipoprotein lipase mass reflects insulin resistance and may be deeply involved in the progression of coronary arteriosclerosis.