DOSE-DEPENDENT EFFECT OF NICERITROL ON PLASMA LIPOPROTEIN-A

Lipoprotein-a, Lp(a), is a variant form of low density lipoprotein (LD L) that contains apolipoprotein-a, whose structure has 75-85% homology with plasminogen. Elevated plasma levels of Lp(a) are considered to b e one of the independent risk factors for cardiovascular disease. We s tudied the effects of niceritrol, a nicotinic acid derivative, on plas ma Lp(a) levels in 72 patients with hypercholesterolaemia. The dose of niceritrol was increased every 4 weeks, from 750 to 1500 and then to 2250 mg day(-1). The final dose was adjusted to obtain a plasma choles terol level less than 5.69 mmol l(-1). Niceritrol led to significant d ecreases in plasma levels of median Lp(a), from 16.1 mg dl(-1) (interq uartile intervals, 8.7 to 32.8) to 11.1 mg dl(-1) (interquartile inter vals, 6.6 to 21), the mean reduction rate being 17.6%. In the group wi th pretreatment Lp(a) levels of over 20 mg dl(-1), Lp(a) decreased by 10.0, 22.0 and 31.8% at the doses of 750, 1500, and 2250 mg day(-1), r espectively. In the group with levels less than 20 mg dl(-1), only the dose of 2250 mg day(-1) was effective in the reduction of Lp(a). The results suggest that the reduction of Lp(a) was dependent on the dose of niceritrol and on the pretreatment level of Lp(a). In conclusion, n iceritrol is effective, in a dose-dependent manner, for reducing Lp(a) levels.