The atherogenic role of triglycerides and small, dense low density lipoproteins: impact of ciprofibrate therapy.

Triglyceride levels greater than 150 mg/dl are associated with the atherogenic lipoprotein phenotype, represented by a predominance of small, dense low density lipoproteins (LDL) and diminished concentrations of high density lipoproteins. This phenotype is characteristic of patients with combined hyperlipidemia (CHL). We evaluated the impact of ciprofibrate therapy (100 mg daily) for 1 month on the quantitative and qualitative characteristics of the LDL particle profile in CHL patients (n = 9). Marked reductions in plasma levels of triglycerides (-33%), cholesterol (-15.5%), LDL-cholesterol (-15.2%) and apolipoprotein-B (-22.7%) were accompanied by a significant degree of normalisation in the LDL subspecies profile; such normalisation resulted from a preferential reduction in the elevated levels of dense LDL subspecies (LDL-4 and LDL-5, -43% and -54%, respectively; P < 0.03 and P < 0.006, respectively). Concentrations of light LDL (LDL-1) were also reduced significantly (-30%, P < 0.006), while those of LDL-3 of intermediate density (d = 1.029-1.039 g/ml) were moderately increased (+23%). The ciprofibate-induced normalisation of both the quantitative and qualitative features of the atherogenic LDL particle profile characteristic of combined hyperlipidemia is consistent with a reduction in the elevated cardiovascular risk in the patient group.