Apolipoproteins - coronary heart disease

053. Which of the following is most strongly associated with coronary heart disease?

1. Apolipoproteins

2. VLDL

3. HDL

4. Total liproproteins

Answer

1. Apolipoproteins

Reference

Park 18^th Edition Page 290

Quality

Reader

Status

Repeat

QTDF

Park

Discussion

Recent evidences suggest that levels of plasma apolipoprotein A1 (the major HDL protein) and apolipoprotein B (the major LDL protein) are better predictors of CHD than HDL cholesterol and LDL Cholesterol respectively.

Explanation

Measurement of apolipoproteins may replace lipoprotein cholesterol determination in assessing the risk of CHD

Comments

Apoprotein(a), a large glycoprotein that shares a high degree of sequence homology with plasminogen, is made by hepatocytes and is secreted into plasma where it forms a covalent linkage with the apo B100 of LDL to form lipoprotein(a). The physiologic role of lipoprotein(a) is not known, but elevated levels are associated with an increased risk for atherosclerosis

Tips

Lp(a) (often pronounced "lipoprotein little a" to distinguish it from apolipoprotein AI and others found in HDL) provides a potential link between hemostasis and blood lipids. The Lp(a) particle consists of an apoprotein (a) molecule bound by a sulfhydryl link to the apolipoprotein B moiety of a LDL particle. Apoprotein (a) has homology with plasminogen and may inhibit fibrinolysis by competing with plasminogen. Other risk factors for atherosclerosis related to blood clotting include elevated levels of fibrinogen or of the inhibitor of fibrinolysis, plasminogen-activator inhibitor (PAI) 1.