**EP342: Triglycerides and Heart Disease (Part 1)**
**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, and 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 Bishop:** G'day, Warwick Bishop here. And I'd like to welcome you to my podcast and videocast today. I would like to talk about triglycerides. You've probably heard that word. So triglycerides, they are a fat that travels around in the blood. And there's quite a lot to talk about when it comes to triglycerides. They're super important, and they're a little bit complicated. So I'm pretty keen to go through aspects of triglycerides so we understand them. And then I'd also like to talk about how we manage them or treat them.
**Warwick Bishop:** Triglycerides and the heart. Well, why do we worry about triglycerides? You've probably heard the term triglyceride, this hypertriglyceride, that, etc., etc., and heard it talked about in the context of coronary artery disease. Well, hypertriglyceride levels are associated with cholesterol-rich particles in the bloodstream. Raised triglyceride levels tend to be associated with lower levels of so-called good cholesterol. They tend to be associated with an increased level of the small, dense, low-density lipoprotein particle, so the bad cholesterol. So hypotriglyceridemia, a reduction in the so-called good cholesterol, and of the bad cholesterol... It tends to be associated with the small, dense component, the worst component, rather than the small, fluffy.
**Warwick Bishop:** High triglycerides tend to be associated with holding on to weight around the tummy. We call that central adiposity, or fat. But that central adiposity is also linked to fat being around the organs. Fat can be around the heart, can be around the liver, gastric, the gut, the lining of the gut. We know that raised triglycerides and that extra obesity, that extra carrying of weight is associated with raised blood pressure and also associated with pre-diabetes and diabetes. And all that together is linked with an increased risk of blood clotting. Triglycerides are very significant and a part of a whole constellation of things that seem to go wrong and seem to all keep each other company. So let's talk about them a bit more.
**Warwick Bishop:** So what is a triglyceride? Basically, it's three fatty acids all stuck together on a glycerol backbone. It's the significant energy storage unit within the body. Where do we get them from? We get them from diet, basically. Sources of things like oils, butters, animal fats, and processed foods. We break down those fats in our small intestine, and then they're repackaged together in the lining of the stomach and released into basically the lymphatic system. So they eventually get into the bloodstream and travel around the body.
**Warwick Bishop:** So triglycerides are consumed as part of what we're eating. The fatty acids are broken down. They're absorbed with monoglycerides. Bile salts help in that process. Cells that line the gut create the small particles that carry these triglycerides around in the bloodstream. These triglycerides end up in things called chylomicrons. And chylomicrons travel through lymphatic channels and eventually into the bloodstream to make their way to the liver, where they deliver, if you like, their payload of energy there—triglycerides. The liver will facilitate those triglyceride chylomicron bundles being broken down to very low-density lipoproteins, low-density lipoproteins, high-density lipoproteins, and intermediate-density lipoproteins. So you can see that they're really important as some of the constituents and components of the particles that zip around in our body.
**Warwick Bishop:** Remember that glycerol and free fatty acids are taken to our adipose cells, our fat cells, and to our muscle cells, to the first for storage, to the second for energy. So, fascinating and interesting complex system. There are things that can impact our level of triglycerides. And we know that if people consume significant amounts of carbohydrate, these get converted to triglycerides. How does that work? Well, glucose gets transformed into pyruvate. Pyruvate, which is a chemical compound, goes through the TCA cycle to produce citrate. Citrate is converted into acetyl-CoA, and acetyl-CoA is a building block for fatty acids. So carbohydrate consumption drives increased levels of acetyl-CoA, and acetyl-CoA leads to the building blocks for fatty acid production, and those fatty acids need to be transported as triglycerides.
**Warwick Bishop:** It turns out that alcohol can also increase acetyl-CoA. So what happens is when we consume alcohol, we have alcohol dehydrogenase convert that alcohol or ethanol into acetaldehyde. Acetaldehyde dehydrogenase then works on that acetaldehyde to create acetate. Acetate can then be converted by the liver into acetyl-CoA. As I've already said, acetyl-CoA to fatty acids to triglycerides, and we push our triglycerides up again. Now, I'm not expecting you to remember those complex biochemical pathways, but we do know by looking at those pathways that feeding in either glucose or alcohol, the final common outcome will be driving fatty acid synthesis, and therefore triglyceride production.
**Warwick Bishop:** Well, what do we do when our triglycerides are elevated? We can undertake physical activity. So what happens with physical activity or exercise and our triglycerides? Well, we've got really robust information that shows us as we exercise, we will lower our triglyceride levels. Well, why is that? Triglycerides, as I mentioned, are an energy source. It makes perfect sense that if we use an energy source as we do when we exercise, then of course we're going to lower those energy reserves. So exercise is a fantastic way to keep those triglyceride levels down. Exercise is also beneficial because it contributes to insulin sensitivity as well. And we might touch on that a little bit later on.
**Warwick Bishop:** When it comes to exercise, how much is recommended? Well, current guidelines in the US and Australia would suggest about 150 minutes per week broken down over a number of days. But honestly, exercise, if you can incorporate it into your day-to-day, that's brilliant. And although that's a recommendation, by no means is it a minimum. So exercise is a real fountain of youth. So please embrace it, and it will help your triglycerides.
**Warwick Bishop:** What about insulin resistance and weight? Well, we know that insulin resistance, which is when someone's insulin production is very high compared to someone who's not insulin resistant or insulin sensitive, when they're exposed to carbohydrate. So if you're exposed to carbohydrate, the body senses that it produces insulin. The higher the amount of insulin produced, i.e., the more insulin resistant someone is, the more likely they are to have raised triglycerides, lower HDL, so-called good cholesterol, and smaller bad cholesterol particles. Now we don't like those small bad cholesterol particles because we think they're more likely to get into the artery. All these things come, if you like, as a gang of usual suspects in that setting of insulin resistance. And they tend to be closely linked to people who are carrying excess weight or obesity.
**Warwick Bishop:** So this combination, the triad of higher triglycerides, lower good cholesterol, and smaller, denser, bad cholesterol, are all part of insulin resistance, but insulin resistance is closely linked to carrying extra weight as well. That extra weight is associated with raised blood pressure and associated with inflammation. So there’s a very complicated interaction and interplay between triglycerides, the other lipid markers in the blood, insulin, and cardiovascular disease.
**Warwick Bishop:** But where do triglycerides fit in with atherosclerosis? Well, when you actually look at an atherosclerotic plaque and study it with mass spectrometry and all the things that you might use to try and identify if triglycerides themselves end up in an atherosclerotic plaque, well, it turns out triglycerides don't end up in the plaques that we're worried about. So they're not a direct contributor to coronary artery disease in that way. So we probably think broadly in the medical community that they are a marker of what's going on in the body and therefore in the bloodstream. So they're a marker of metabolic health. And that's why these associations with lower HDL particles, smaller LDL particles, central adiposity, visceral fat, inflammation—all these things are probably the drivers. And triglycerides, they're not really an innocent bystander, but they're not the main driver. They're more likely to be a marker of the underlying processes, the metabolic health of someone that's really driving major issues.
**Warwick Bishop:** Well, that's a bit about triglycerides, and what I'd like to do next is talk about how we manage triglycerides. But I've covered quite a lot in this presentation so far, so what I'd really, really like to do is to take a break and come back and share managing triglycerides in a part two on this particular complicated topic. So for now, I'd like to thank you for tuning in. If you have any queries or questions, please drop us a note, as always, at info@drbishop.online. It is my privilege and pleasure to share. And if you found this valuable, please share this with someone else. They may well want to know exactly the same. They may have raised triglycerides and be wondering a little bit about it.
**Warwick Bishop:** This particular podcast should be available as a video as well. And there are some images that will go with it. Hopefully, you were able to grasp enough of that without the images. But there's an image version as well, so search that if you're interested. For now, I'm going to say goodbye. I'm going to wish you the very best and hope you live as well as possible for as long as possible. Take care and bye for now.
**Warwick Bishop:** Did you know that coronary artery disease kills one in four people? So most of us are likely to carry some risk or know someone who does. If you're interested in finding out more about how to evaluate that risk, check out www.virtualheartcheck.com.au. It'll give you information about risk and what else can be done to be even more precise.
