Our investigations indicate that most patients with moderate hypertriglyceridemia have marked defects in the metabolism of low-density lipoprotein (LDL) apolipoprotein B. Moreover, these patients have 2 major defects in the metabolism of triglyceride-rich lipoproteins, i.e., an accumulation of remnant lipoproteins (due in part to delayed hepatic clearance) and increased fractional conversion of very-low-density lipoprotein (VLDL) to LDL. Defective triglyceride-rich lipoprotein metabolism has been associated with insulin resistance. Statin therapy in hypertriglyceridemic patients improves the lipoprotein profile by decreasing both LDL cholesterol and remnant lipoproteins. However, statin therapy does not normalize LDL apolipoprotein B metabolism, and high-density lipoprotein (HDL) cholesterol levels remain low. Therefore, consideration may be given to combining a statin with a drug that alters triglyceride metabolism (e.g., fibrate or nicotinic acid) in high-risk patients with hypertriglyceridemia. (C) 1998 by Excerpta Medica, Inc.