From the Guidelines
Apolipoprotein B (ApoB) is a protein that plays a crucial role in the transport of cholesterol and triglycerides throughout the body, serving as a primary structural protein in several types of lipoproteins, including VLDL, IDL, and LDL. ApoB is essential for the assembly and secretion of these lipoproteins from the liver and intestines, and it also functions as a ligand that binds to LDL receptors on cell surfaces, facilitating the uptake of cholesterol into cells [ 1 ].
Key Points
- Elevated levels of ApoB in the blood are strongly associated with an increased risk of atherosclerosis and cardiovascular disease, making it a valuable biomarker for assessing cardiovascular risk [ 1 ].
- ApoB provides a direct measure of the number of atherogenic particles present in the circulation, as each lipoprotein particle contains one ApoB molecule [ 1 ].
- Measuring ApoB levels may provide a more accurate assessment of cardiovascular risk than traditional cholesterol measurements, particularly in individuals with metabolic disorders like diabetes or metabolic syndrome [ 1 ].
- The measurement of ApoB may have advantages in certain circumstances, particularly in patients with hypertriglyceridemia [ 1 ].
- A persistent elevation of ApoB can be considered a risk-enhancing factor, with a level >130 mg/dL corresponding to an LDL-C level $160 mg/dL [ 1 ].
From the Research
Definition and Function of Apolipoprotein B
- Apolipoprotein B (apoB) is a primary structural and functional component of low-density lipoprotein (LDL) 2.
- ApoB is essential for the assembly of triglyceride-rich very low-density lipoproteins (VLDL) in the liver and for their secretion into the plasma 3.
- ApoB plays a crucial role in lipid and cholesterol metabolism, and is a key agent in the development and progression of atherosclerosis 2.
Apolipoprotein B as a Marker of Cardiovascular Risk
- ApoB is considered a more accurate marker of cardiovascular risk than low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) 4, 5.
- The European Society of Cardiology/European Atherosclerosis Society has stated that apoB is a more accurate measure of cardiovascular risk and a better guide to the adequacy of lipid lowering than LDL-C or non-HDL-C 4, 5.
- Studies have shown that apoB levels can modulate the risk of coronary heart disease associated with increased concentrations of LDL cholesterol 6.
Physiological Mechanisms of Apolipoprotein B
- The physiological mechanisms responsible for the superiority of apoB as a marker of cardiovascular risk include the nature and relative numbers of atherogenic apoB lipoprotein particles, such as chylomicron remnants, very low-density lipoprotein, and low-density lipoprotein particles 5.
- The total number of apoB particles determines cardiovascular risk, except for dysbetalipoproteinemia 5.
- The mechanisms that govern the number of very low-density lipoprotein and low-density lipoprotein particles, as well as the cholesterol mass within these particles, are responsible for the discordance between the mass of cholesterol within apoB particles and the number of apoB particles 5.