Changes in serum and lipoprotein lipids, and apolipoprotein B and A-I, in patients with different types of primary hyperlipoproteinaemia treated with gemfibrozil.

: Gemfibrozil was given at the dose of 600 mg twice daily to 16 type IIa, 13 type IIb and 11 type IV hyperlipoproteinaemic patients for four months. At the end of the fourth month of therapy low-density lipoprotein (LDL) cholesterol decreased on the average by 18% in type IIa, by 11% in type IIb and increased by 37% in type IV patients. Very-low-density lipoprotein (VLDL) cholesterol and triglycerides fell by 57% in type IIb and by 58% and 76% respectively in type IV subjects. High-density lipoprotein (HDL) cholesterol rose in all groups of patients owing to the increase of the HDL2 subfraction. However, in type IIa the change did not reach the level of statistical significance. Apoprotein B decreased in type IIa and in type IIb patients and apoprotein A-I significantly increased in type IIb and IV patients. The individual changes in total VLDL and LDL lipids and in apoprotein B could be related to their pretreatment level. The cholesterol triglyceride ratio significantly increased in LDL and HDL fractions and the effect was greater in the subgroup of patients with the greatest abnormality in lipoprotein lipid composition. On the whole the differential effects of gemfibrozil on serum lipoprotein concentration and composition in the various types of hyperlipoproteinaemia can be regarded as a trend toward a normalization and may be explained by the multiple effects of the drug on lipid metabolism.