EP339: What's This ApoB All About?

Welcome to my podcast. I am Doctor Warrick Bishop, and I want to help you to live as well as possible for as long as possible. I’m a practising cardiologist, best-selling author, keynote speaker, and the creator of The Healthy Heart Network. I have over 20 years as a specialist cardiologist and a private practice of over 10,000 patients. EP339: What's This ApoB All About? Dr. Warwick Bishop, a cardiologist and CEO of the Healthy Heart Network, hosts this episode dedicated to explaining ApoB and its relevance to heart health. Building on awareness raised by Dr. Peter Attia in the longevity space, the episode explores what ApoB is, its clinical utility, and whether it should be routinely measured alongside standard cholesterol panels. Key Takeaways: ApoB (ApoB100) is a protein that makes up lipoprotein particles, which transport cholesterol and fats throughout the bloodstream in protective protein "balls" rather than floating freely. ApoB measurement indicates the number of cholesterol-carrying particles in the blood, whereas LDL cholesterol measures concentration per volume—a subtly different but important distinction. ApoB is present in all cholesterol particles except HDL (which uses ApoA protein instead), making it a useful marker for total atherogenic particle burden. A greater number of particles carrying cholesterol and lipids increases the risk of plaque formation in arteries, making ApoB relevant to cardiovascular risk assessment. Triglyceride levels on a standard lipid panel can effectively indicate whether small, dense LDL particles are present—if triglycerides are under 1.2 millimoles per litre, small dense particles are unlikely. Elevated triglycerides often reflect insulin resistance, prediabetes, or diabetes and are associated with increased small, dense LDL particles. Standard cholesterol interventions that lower LDL cholesterol and triglycerides will inherently lower ApoB, making additional ApoB testing potentially redundant. All existing cardiovascular outcome research is based on LDL cholesterol levels, not ApoB, so clinical decision-making continues to rely on traditional lipid panels. In Australia, ApoB is not currently covered by Medicare rebates, making it an additional out-of-pocket expense without clear clinical advantage over standard panels. While ApoB provides interesting academic context about particle numbers, clinicians can effectively infer this information from standard cholesterol and triglyceride measurements without routine ApoB testing.