FREQUENTLY ASKED QUESTIONS

Cholesterol forms an essential component of animal cell walls. They help synthesize hormones like steroids, testosterone, estrogen, progesterone, aldosterone, vitamin D and bile acids.

It is also involved in cell signalling and nerve conduction.

Cholesterol efflux is a specific process that is regulated by a number of intracellular transporters, such as ATP binding cassette transporter proteins A1 (ABCA1) and G1 (ABCG1) and scavenger receptor type B1.

A lipoprotein is a biochemical assembly that contains both proteins and lipids. The proteins serve to emulsify the lipid molecules. Being bound to the proteins will allow fats to move through the water inside and outside cells. Examples include the plasma lipoprotein particles classified as HDL, LDL, IDL, VLDL and chylomicrons.

Apolipoproteins are proteins that bind lipids (oil-soluble substances such as fat and cholesterol) to form lipoproteins. They transport lipids (and fat-soluble vitamins) in blood, cerebrospinal fluid and lymph.

There are multiple classes of apolipoproteins and several sub-classes: · apolipoprotein A (apoA1, apoA2, apoA4, and apolipoprotein A-V (apoA5)) · apolipoprotein B (apo B48 and apo B100) · apolipoprotein C (apo C-I, apo C-II, apo C-III, and apo C-IV) · apolipoprotein D · apolipoprotein E · apolipoprotein H · apolipoprotein L

Cholesterol efflux (transported) from peripheral tissues to the liver is a key function of HDL particles and is the first step in the pathway termed “reverse cholesterol transport” for cholesterol removal from peripheral tissues such as the walls of blood vessels to the liver for biliary excretion.

· Currently available cholesterol-lowering drugs like the statins may not effective in reducing cardiovascular risk in subjects with a low cholesterol efflux capacity.

· Independent of the plasma HDL-C levels; Cholesterol efflux capacity (CEC) is inversely associated with prevalent Atherosclerotic Cardiovascular Disease and Incident Cardiovascular Events:

Ø In previously undiagnosed subjects or subjects with no preexisting disease

Ø In subjects undergoing treatment for a wide range of cardiovascular disease

CEC will help stratify the risk profile of the patient. Patients with lower CEC may be at a high risk of cardiovascular events, poor response to currently available cholesterol-lowering medications, patients with low CEC may need a different strategy to reduce their cardiovascular risk and for better outcomes.