Hypertriglyceridemia Characterized by Low-Density Lipoprotein Phenotype and Lipoprotein Lipase Gene Mutation

A high serum triglyceride (TG) concentration is associated with an increased serum concentration of small, dense low-density lipoprotein (LDL). To further characterize the hypertriglyceridemic condition, we examined sera from 240 subjects for small, dense LDL using non-denaturing polyacrylamide gradient gel electrophoresis. We focused on determining the frequency of the pattern B, which is characterized by a higher proportion of small, dense LDL, among hypertriglyceridemic individuals. The subjects were divided into four groups: a control group (TG < or = 1.65 mmol/l, high-density lipoprotein cholesterol (HDL-C) > or =1.17 mmol/l; n = 71), a high TG group (TG > 1.65 mmol/l, HDL-C > or = 1.17 mmol/l; n = 36), a group with high TG and low HDL-C (TG > 1.65 mmol/l, HDL-C < or = 0.91 mmol/l; n = 106), and a low HDL-C group (TG < or = 1.65 mmol/l, HDL-C < or = 0.91 mmol/l; n = 27). We found that pattern B occurs at a high frequency mainly in individuals with high TG and low HDL-C levels. We also observed an increased percentage of LDL within the 20.0 nm to 25.5 nm particle diameter range in this group. Analysis of the lipoprotein lipase gene in this group showed that some mutations seem to be associated with small, dense LDL, resulting in LDL pattern B.