Effect of Non-Statin Lipid Lowering and Anti-Obesity Drugs on LDL Subfractions in Patients with Mixed Dyslipidaemia

Small, dense low density lipoprotein (sdLDL) particles are considered an emerging cardiovascular risk factor. Obese patients with mixed dyslipidaemia frequently have elevated sdLDL cholesterol (sdLDL-C) levels. Therefore, agents that favourably modulate the LDL phenotype may be of clinical value in these patients. We review the efficacy of anti-obesity and lipid lowering drugs other than statins on LDL subfractions in patients with mixed dyslipidaemia primarily focusing on those who are overweight/obese. The literature search was based on PubMed listings up to 26 November 2009. In most studies ezetimibe decreases the large and medium LDL subclasses and, to a lesser extent, the sdLDL particles, while it does not substantially influence LDL size. Fibrates and niacin reduce sdLDL particles and shift LDL size towards large, buoyant LDL particles. More studies are needed to elucidate the effects of fish oils and resins on LDL phenotype. Orlistat and rimonabant have been associated with reductions in sdLDL-C levels along with an increase in LDL particle size. We did not find any literature describing the effect of sibutramine on sdLDL profile. Treatment with fibrates and niacin seems to be beneficial in patients with mixed dyslipidaemia. The addition of orlistat may further improve LDL phenotype in overweight/obese patients.