Apolipoprotein a-i

apolipoprotein A-I

Apolipoprotein A-I is the main protein component of HDL particles and plays a central role in moving cholesterol out of tissues. It helps HDL pick up cholesterol from cells and activates an enzyme that changes cholesterol into a form the body can transport more easily. Because of these actions, apolipoprotein A-I is important for the reverse transport process that protects blood vessels from cholesterol buildup. Levels of this protein in the blood can reflect how well HDL is working, sometimes better than measuring HDL cholesterol alone. Genetic differences, diet, exercise, and certain medical conditions influence apolipoprotein A-I levels. Scientists are studying therapies that boost or mimic this protein as a way to reduce cardiovascular risk. Measuring apolipoprotein A-I can add information when doctors assess heart disease risk, especially in complex cases. Like HDL itself, the protective effect depends on how functional the particles are, so researchers focus on quality as well as quantity. Understanding this protein helps explain why some people with normal cholesterol numbers still have cardiovascular problems. It is a promising target for future treatments aimed at improving cholesterol handling in the body.