Changes in serum lipoprotein(a) in hyperlipidemic subjects undergoing long-term treatment with lipid-lowering drugs.

Though the exact physiology and pathology of lipoprotein(a) [Lp(a)] remains unknown, it has been demonstrated that increased serum Lp(a) levels are correlated with an increased risk of atherosclerotic vascular disease. The effects of lipid-lowering drugs on Lp(a) levels is unclear because of inconsistencies between study designs. This study analyzes the effects of the commonly used lipid-lowering drugs pravastatin (PRAV), lovastatin (LOV), and cholestyramine (CHOL) on serum Lp(a) and other serum lipid levels in a parallel study design. Hyperlipidemic men (n = 32) were enrolled from three centers and treated for 48 weeks in a multicenter clinical trial using PRAV, LOV, CHOL, or a placebo (for the first 16 weeks only). Baseline serum low-density lipoproteins (LDL-C), high-density lipoproteins (HDL-C), and triglycerides were 199 +/- 38, 40 +/- 9, and 160 +/- 70 mg/dl, respectively. At the end of 48 weeks, serum plasma LDL-C declined in patients randomized to PRAV, LOV, and CHOL, respectively, by 31%, 29%, and 23% (all p < 0.001); HDL increased by 4%, 11%, and 11% (all p < 0.001); and TG changed by -16%, -28%, and +43% (all p < 0.001). Subjects in PRAV and LOV changed Lp(a) by 9% and 3%, respectively. Although there was an initial Lp(a) decline in the first 8 weeks of CHOL therapy (p < 0.05, ANOVA), this returned to baseline after 48 weeks. In this parallel study design PRAV, LOV, and CHOL are effective LDL-lowering medications with minimal effects on plasma Lp(a).