Effect of gemfibrozil on the composition and oxidation properties of very-low-density lipoprotein and high-density lipoprotein in patients with hypertriglyceridemia.

Recent studies suggest that both oxidized very-low-density lipoprotein (VLDL) and oxidized high-density lipoprotein (HDL) may play a role in the pathogenesis of atherosclerosis. Gemfibrozil is widely used and is reported to decrease VLDL levels and increase HDL levels. The aim of this study was to investigate the effect of gemfibrozil on the chemical composition and oxidative susceptibility of VLDL and HDL and their relationship with atherosclerosis. Twenty patients with hypertriglyceridemia were treated with 300 mg gemfibrozil, 3 times daily, for 12 weeks. Venous blood samples were collected before treatment, at the end of treatment, and 4 weeks after the end of treatment. Gemfibrozil effectively lowered concentrations of plasma lipid, apolipoprotein (apo) B, and apo E. The lipid and protein content of VLDL were also decreased, but not by the same extent. The surface-to-core ratio and apo E/apo B ratio of VLDL particles were increased after gemfibrozil treatment. HDL(2) cholesteryl ester and HDL(3) apo A-II content were also increased. Gemfibrozil treatment lowered levels of lipid peroxides in both VLDL and HDL particles. The susceptibility of VLDL to oxidation was unchanged, whereas maximal peroxide production was decreased. The oxidative susceptibility of both HDL(2) and HDL(3) decreased with gemfibrozil treatment. These results indicate that after gemfibrozil treatment, VLDL and HDL particles in patients with hypertriglyceridemia are less atherogenic, which may explain why gemfibrozil treatment is beneficial in terms of coronary heart disease in hypertriglyceridemia.