Effects of nicotinic acid on concentrations of serum apolipoproteins B, C-I, C-II, C-III and E in hyperlipidemic patients.

Twenty-four patients with Type IIa, IIb, III and IV hyperlipoproteinemia (HLP) were treated with 4 g of nicotinic acid daily with the purpose to study its effect on serum apolipoprotein B, C-I, C-II, C-III and E concentrations. Triglyceride and total cholesterol concentrations of whole serum and of different serum lipoprotein fractions were also determined. Analyses were performed prior to and after a drug treatment period of 6 weeks, during which all the patients were weight stable. Treatment caused a decrease in serum concentrations of apolipoproteins C-I, C-II, C-III and E. These highly significant reductions were all positively correlated to a reduction of very low density lipoprotein triglyceride levels of serum (r-values greater than 0.76, p less than 0.001). There were highly significant decreases in serum levels of apolipoprotein B and low density lipoprotein total cholesterol. These reductions were positively intercorrelated (r = 0.55; p less than 0.01). Similar effects were observed in the different HLP types and in both sexes. Treatment resulted in normolipidemia in 12 patients, who were hypercholesterolemic (7 type IIa, 3 type IIb, 2 type III hyperlipoproteinemia) prior to treatment. The serum apolipoprotein B concentrations of these 12 patients fell after therapy to values which, however, remained abnormally high. We suggest that serum lipid adjusting treatment should aim at a normalization not only of serum lipid concentrations but also of the serum apolipoprotein B concentration in order to achieve a maximal antiatherogenic effect.