Effects of gemfibrozil on plasma lipoproteins, plasma activities of hepatic enzymes, and hemostatic variables in hypertriglyceridemic patients

In 15 patients with hypertriglyceridemia-defined as plasma triglyceride (TG) concentration >250 mg/dL-gemfibrozil 600 mg given twice daily for 4 months significantly reduced the mean plasma concentration of total cholesterol (TC) (-15%) and TG (-61%). In the low-density lipoprotein (LDL) fraction, the TC concentration was unchanged but the TG concentration was decreased. As the apoprotein B concentration also decreased, it is likely that the LDL particles were not only enriched with TC but also reduced in number. The increase in high-density lipoprotein cholesterol (HDL-C) was accounted for by an increase in the TC content of HDL(3). Most of these changes can be considered beneficial in terms of protection against atherosclerosis. The plasma activities of lecithin-cholesterol acyltransferase and hepatic lipase were not changed significantly by the drug, while that of lipoprotein lipase increased significantly (44.1%, P < 0.05). Thus the mechanism of action of gemfibrozil appears to mainly involve an increased catabolism of TG-rich lipoproteins, although the correlations between lipoprotein lipase and lipoprotein concentrations were only marginally significant, As significant correlations were found between hepatic lipase and HDL-C, gemfibrozil appears to also have some impact on hepatic lipase. Finally, gemfibrozil did not change the activity of the fibrinolytic system, while the fibrinogen concentration and the platelet count increased, The significance of the latter changes is unclear.