Rationale for using apolipoprotein B and apolipoprotein A-I as indicators of cardiac risk and as targets for lipid-lowering therapy
Abstract
Rationale for using apolipoprotein B and apolipoprotein A-I as indicators of cardiac risk and as targets for lipid-lowering therapy This editorial refers to ‘Prognostic value of apolipoprotein B and A-I in the prediction of myocardial infarction in middle-aged men and women: results from the MONICA/KORA Augsburg cohort study’ † by C. Meisinger et al. , on page 271 Introduction Although low density lipoprotein (LDL) is recognized as the primary lipid-related risk factor, and therefore the primary target for lipid-lowering therapy, 1 – 4 there are in fact several limitations of only using LDL cholesterol (LDL-C) as the primary risk variable. 5 , 6 New data are accumulating which speak in favour of apolipoproteins (apo) as more informative risk indicators/factors. ApoB, which indicates the number of potentially atherogenic lipoprotein particles, and apoA-I, which reflects anti-atherogenic high density lipoprotein (HDL) particles, may be additional lipid-related variables that more accurately indicate cardiovascular (CV) risk than LDL-C. Thus, several studies have shown that apoB and apoA-I are strong predictors of myocardial infarction (MI). 7 – 9 The two largest of these studies are the AMORIS 7 and the INTERHEART 9 studies which both show a very strong direct relation between a high apoB/apoA-I ratio and an increased risk of fatal MI 7 and acute MI (AMI). 9 Meisinger et al. 10 add another piece of important information along the same lines. Physiological and pathophysiological aspects of apoB and apoA-I metabolism ApoB is present in very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), large buoyant LDL, and small dense LDL (sd-LDL), with one molecule of apoB in each of these atherogenic particles. Thus, total apoB reflects the total number of atherogenic particles ( Figure 1 ). It is the apoB in the particles that leads to entrapment of these lipoproteins in the arterial wall. ApoB produced in the liver also stabilizes and allows the transport of cholesterol and triglycerides in plasma VLDL, IDL, large buoyant LDL, and sd-LDL ( Figure 1 ). In addition, apoB serves as the ligand … Full Text of this Article * Corresponding author. E-mail address : goran.walldius@astrazeneca.com Related articles Clinical research : Christa Meisinger , Hannelore Loewel , Wilfried Mraz , and Wolfgang Koenig Prognostic value of apolipoprotein B and A-I in the prediction of myocardial infarction in middle-aged men and women: results from the MONICA/KORA Augsburg cohort study Eur Heart J ( February 2005 ) 26 ( 3 ): 271 - 278 first published online November 30, 2004 doi: 10.1093/eurheartj/ehi003 Abstract Full Text (HTML) Full Text (PDF)