**EP394: The REAL Truth About Cholesterol**
**Dr. Auric Bishop:** Welcome, my name's Dr. Auric Bishop. I'm a cardiologist, an author, and a keynote speaker. I'm CEO of the Healthy Heart Network. I'm all about trying to help people live as well as possible for as long as possible. Heart disease is huge in Australia. Every 20 minutes, someone suffers a heart attack. Most of these could probably have been avoided if only we knew what to do. This podcast is all about helping you understand blood pressure, weight, cholesterol, for better health. If you enjoy this podcast, I would be honoured for a five-star review. You can share it with your family and friends. It may well save someone you love.
**Warwick:** G'day, it's Warwick here. And I'd like to share with you today a bit more on cholesterol. I know it comes up a lot. I know I talk about it a lot. But it's really important. We know that coronary artery disease affects one in four people, and we know many people are on cholesterol-lowering agents with really good effect. We know there are many people who have apprehension about being on cholesterol-lowering agents, and we know there are many people who don't even know if they should be on cholesterol-lowering agents or even what their cholesterol is. So let's chat about it a little bit because, well, I think it's super important.
As we do that, let's just have a think about the most important bits around the basics of cholesterol. And I'm going to call this presentation "Cholesterol Basics" and talk about what really matters. Cholesterol is important for the formation of some of our sex hormones; it's important for the formation of vitamin D, and it helps transport fat-soluble vitamins around the body. When we're talking about what's in the blood, we're talking about things called LDL cholesterol and HDL cholesterol. If you've heard those terms, well, low-density lipoprotein is actually not cholesterol. Low-density lipoprotein and high-density lipoprotein are, in fact, the things that transport cholesterol around the body. They're packages, if you like, vehicles that cholesterol, the molecule, sits inside.
Triglycerides are not the vessel or the vesicle or the transport module; triglycerides are the molecule. So it's really important to understand the difference and that we need to move cholesterol and other fats around the body. What we often get wrong when we're talking about cholesterol are these polarizing remarks that all LDL cholesterol is bad and all HDL cholesterol is protective because it's not always like that. It's often more complicated. Often, we see people who do have high LDL cholesterol but don't necessarily have plaque in the arteries, and equally, we see people who don't have high LDL cholesterol and yet have a buildup of plaque in their arteries. So it's not straightforward. HDL is not always protective, and triglycerides, although triglyceride particles don't end up in the arteries, do present or allow us to have a better idea of someone's metabolic risk of developing problems.
So what we tend to see is people with high cholesterol and bad arteries. We seem to see people with high cholesterol and good arteries, but we also see people with low cholesterol and good arteries, as you might expect. But almost contrary to what we imagine, we see people with low cholesterol and bad arteries. So this is really frustrating and tricky, but it reminds us that it's more complicated than cholesterol alone.
So what really does allow us to predict what's going on in the arteries? Well, importantly, coronary artery calcium scoring is right at the top of my list of go-tos to try and understand what's happening in someone's arteries. We can look at the number of particles that someone has. So ApoB is the protein that's associated with the low-density lipoprotein particle. ApoB gives us an idea of the number of particles. The greater the number of particles, the greater the risk. Similarly, as we were talking about calcium scores, the greater the score, the greater the risk. We can use the total triglyceride to HDL ratio as a predictor of risk. We can look at lipoprotein little a, which is a metabolic marker as well.
When we think about statin therapy, we need to understand who's going to benefit. Well, generally, we think, without question, people who've had an event. So in a secondary prevention scenario, there's almost no question that a low cholesterol for someone who's had an event would be beneficial. But the primary prevention setting, before someone's had an event, is far more complicated. Who needs to be helped there? Who should be on therapy? Which risk patients would need to be considered? And that's a bit of a no-brainer. People with raised cholesterol, diabetes, hypertension, a risk calculator that puts them in a high risk.
But here we can use things like imaging to look at people's arteries and be more precise and figure out if those individuals will benefit or not. Remember, there's a lot of social media confusion out there, and that is often misinformation around where the signs are. It's uncommon for social media statin naysayers to admit that lowering LDL cholesterol for those secondary prevention high-risk patients is problematic; they won't say, because all the data over the last 30-odd years clearly supports lowering cholesterol for those high-risk individuals. But quite reasonably, the confusion sits around who should be on cholesterol therapy before they've had an event.
And this is where polarizing views can come in and cause all sorts of uncertainty and outbreak. I think that we really need a balanced and sensible approach to this situation and do it on an individual-by-individual basis so we know what we're dealing with for that person. I personally believe imaging brings an enormous amount of extra information to that situation so we can make the best decisions for that reason. Because we do see people with relatively increased levels of low-density lipoprotein or so-called bad cholesterol, but they don't have much going on in their arteries and would appear to be at low risk. Similarly, you see those people with normal low-density lipoprotein particle numbers in their blood, but still have plaque in their arteries.
So it's more complicated than that. We've really touched on this in a couple of chapters in the book, "Cholesterol Explained," which is not far from being released, because it really is important to deconstruct some of the complexity and move away from the sound bites that cholesterol is good or bad. It is about the whole picture. And that whole picture includes other things to do with local factors within the artery. Things like inflammation, insulin resistance for the individual, and plaque stability are really important as well. We know that tying in triglycerides and them being a marker of metabolic health is also really important.
So my takeaway on this? I really think for a primary prevention setting, there's no question that personalizing risk and understanding where people sit is incredibly valuable. For secondary prevention, every bit of research we've got clearly indicates that if you've had an event and you've defined yourself as someone who puts plaque in the arteries, which carries a risk of an event or a requirement of an intervention, then lowering cholesterol for you is really, really important. When it comes to coronary artery disease, cholesterol is a piece of the puzzle. It's not the whole story.
One of the things that I think is super important is to empower patients with clarity regarding what we're going to do for their care in the longer term. I hope you found that interesting. If you are looking for even more information on cholesterol and you want to understand it a bit more, keep an eye out for "Cholesterol Explained." It will be available soon. But for now, I'm going to wish you the very best. Take care and bye for now.
**Warwick:** Hi. Ever wondered what your risk of heart attack is? You should. It's the single biggest killer in the Western world. We're talking one death less than every 30 minutes in Australia. One death less than every 60 seconds in the United States. Nine million deaths globally per annum. Well, how do you check your risk? Well, you can go to www.virtualheartcheck.com.au. You'll find out about your risk and what can be done. Beyond that, to be even more precise.
