In this podcast episode, we talk about cardiovascular labs with naturopathic cardiology expert, Daniel Chong, ND. Chong discusses the use of cholesterol panels and other tests he uses in practice. He dispels some common myths about how to interpret different lab results.
Approximate listening time: 27 minutes
About the Expert
Daniel Chong, ND, has been a licensed naturopathic physician, practicing in Portland, Oregon, since 2000 and focusing on risk assessment, prevention, and drug-free treatment strategies for cardiovascular disease and diabetes, as well as general healthy aging, and acute and chronic musculoskeletal injuries. Chong has also completed certificate training in cardio-metabolic medicine from the American Academy of Anti-Aging Medicine and is an active member of the Society for Heart Attack Prevention and Eradication (SHAPE). In addition to his clinical work, Chong serves as a clinical consultant for Boston Heart Diagnostics Lab.
Tina Kaczor, ND, FABNO: Hello I'm Tina Kaczor editor-in-chief at the Natural Medicine Journal. I'm speaking today with my friend and colleague Dr. Daniel Chong a naturopathic physician and specialist in cardiology specifically. Dr. Chong is a founder and lead consultant at healthyheartacademy.com as well as a consultant for the cardiology industry. Dan, thanks for joining me today.
Daniel Chong, ND: Hello Dr. Kaczor, it's nice to be here.
Kaczor: We have talked informally, and I thought this would be a great opportunity to talk specifically for our audience, about the use of cholesterol panels, and we'll go into specifically some breakdown of the usefulness of common cholesterol panels, and then break that out into more particular cardiology panels. There's a lot out there right now about whether cholesterol is or isn't even linked to heart disease, so let's just start at the beginning. Can you give us a little bit about the roots of the cholesterol theory? We'll branch off from there.
Chong: I can try. It definitely is a relatively long-standing theory now. As I understand it, the first thoughts as to whether or not cholesterol had anything to do with cardiovascular disease came in the early 1900s on animal research with rabbits, but at that point it was dismissed because people were still not clear whether or not you could make any correlations between findings in rabbits and extrapolate out to humans.
The major real focus on the connection between cholesterol and heart disease started more in the mid-1900s almost simultaneously in a way with Ancel Keys and the Framingham study, so they started around the same time. Ancel Keys was one of the first people to really make a point of saying, "We should really research this because we repeatedly are seeing this potential connection," and so he was one of the first people to really start trying to splice it out. Then, the Framingham study started simultaneously. They don't come out with any of their more definitive conclusions until a little later than him with that. That's where it all began as far as I understand it.
Kaczor: In the Framingham study specifically I know that there has been ... The broad interpretation in the professional world has been high cholesterol equals risk of heart disease, LDL being the "bad cholesterol," in general. Is there particular subpopulations that this is more true for? In other words, can we say if you are a 40 or 50 something-year-old male this is more true than if you're a 80-year-old male, or a female? Is there any way to delineate that with just looking at broad generic cholesterol levels, nothing too specific yet?
Chong: Hopefully, it will be answering your question by saying this, but to me one of the most fascinating pieces of information I heard come out of the Framingham study in particular is that over the course of however many years ... this was a statistic we heard about maybe five or so years ago. The Framingham study had been active for well over 50 years and they had well over 50 years of data on how many thousands of people, and the statement was made by the former director of the Framingham study, so it was certainly legitimate. Essentially what they said was, one of the key pieces of information that they saw in terms of the relationship between at least total cholesterol and cardiovascular disease was that it appeared as though if a person's total cholesterol was at or below 150 naturally, so throughout their lives without necessarily an intervention with a drug or whatever, just the people in the study who had naturally low cholesterol did not get heart disease period.
Of course, you can't then take that and make any truly definitive statements, but there is, in terms of a general viewpoint that was one of the things that came out. In other words, nobody with cholesterol under 150 naturally got a heart attack in their study. Again, there would still need to be more done to splice that out and figure out what exactly is going on there and why that is, but there's definitely something to be said. You can see the same exact type of finding if you look at epidemiological research on different cultures of people in history who did not get heart disease or got very little heart disease, all of those people regardless of where they were on the planet, what types of specific foods they were eating, even to some extent what their lifestyle was some of these people smoked, et cetera, the cultures of people who were known and found not to get cardiovascular disease all had cholesterol at or below 150.
Kaczor: You're talking about total cholesterol?
Kaczor: Let's move over to talking about the bad cholesterol. LDL-
Chong: Can I pause you for one quick second?
Chong: Just to say one other thing about that. There's a lot of questions that would be immediately raised from those statements that I just made. One other way that I look at things is, and I know we'll get into it more, but cholesterol in of itself, I will say right from the beginning, has to be involved. It is not a worthless thing to measure, it is not something to just disregard and only focus on information. Time and again it has to be involved, technically it has to be involved. You can't make plaque without it, but it's just an important way to think about it. It's just whether or not it's the primary causative factor and we'll get into that.
Kaczor: Yeah, that's an important point. I don't see many people with total cholesterol below 150, but we'll put that aside. It's pretty uncommon. I don't know about other people. Let's break it down-
Chong: In modern times it absolutely it is.
Kaczor: Let's talk about LDL specifically and just start out with there's a lot of more specific labs that are looking at LDL particle size rather than total LDL. Just a brief primer, if you would, on the difference between LDL-
Chong: I like your emphasis on brief.
Chong: Sorry, go ahead.
Kaczor: On LDL calculated as it is in a common cholesterol panel and the particle size as it is measured by several different labs now.
Chong: I'll do two separate simple ways that I look at it. One is technically LDLC or "LDL cholesterol" measurements that are most commonly done in the average physicians' offices et cetera is technically measuring the mass or total amount of cholesterol being carried around on LDL molecules. Just as a reminder to people, these LDL molecules are protein-based particles that are essentially like cargo ships carrying around different substances, one of the main ones being cholesterol.
When you are getting an LDLC you are getting an estimate of the mass of the total amount of cholesterol being a carried around by all of the LDL particles in the system whereas, an LDLP is specifically getting a count of the LDL particles floating around in any one measurement of blood. From an analogy perspective it's like you're counting either the cargo that's being ... The Pacific Ocean has a certain amount of cargo ships out in it carrying cargo and LDLC is like, "Okay, what's the estimate of total cargo being carried around by all of those ships?" Whereas an LDLP would be like, "Okay, we're going to go into the ocean, we're going to count each one of those ships and see how many there are."
Depending on some different factors this is why you could theoretically ... Let's say a cargo ship could technically carry 100 pounds of cargo, you could technically have two ships carrying 200 total pounds of cargo or you could have 20 ships carrying 10 pounds of cargo each. In both cases the LDLC would be the same and yet one, there's 20 ships and the other there's two ships, if that makes sense. The reason why that's so important to make the distinction is that what we know now is that risk specifically goes up with ship count or particle count—not necessarily total mass or total cargo. If you have a way of identifying, "Aha, there is actually only two ships in this ocean versus 20," that can significantly impact risk level.
Kaczor: Looking at the LDLC, which is the calculated one, it may or may not correlate with cardiovascular disease is what I'm hearing you say, and LDLP we can use as a more specific correlation with cardiovascular disease.
Chong: Right, that is correct. In the grand scheme of things when we're also potentially considering other factors like inflammation, and oxidative stress, et cetera, it's still relative ... we're just talking about cholesterol-related markers and their impact on risk, so there are obviously ... I don't want to discount the fact there are other factors involved here, but when we're just talking about the cholesterol and its impact on future risk or not the particle count is what trumps everything. Again, just in the realm of the cholesterol markers.
Just for an example, there's a research study I've seen where they looked at 16-year survival, from year 0 to 16 and measured LDLP and LDLC in each person. This is a very large study, and what they saw is a distinct difference between particle count and future event risk for cardiovascular disease. In other words, you had a distinct increase or higher rate of survival in people who have low particle counts regardless of what their LDLC or mass was. Whereas the people with worse outcomes all had high particles even though some of them technically had low LDLCs or low amount of total mass or cargo.
Kaczor: It's been-
Chong: It's been clearly seen that there's a distinct difference. It's also important to mention here, it is unfortunately true that there are some people out there who are still saying, "If I have large puffy LDL (i.e., my LDL particles are loaded with a lot of cargo per particle) and yet not necessarily ..." If you have a high LDLC, but all of your LDLs are large and puffy, and you also have a high LDL particle count you will still have an increased risk. There are some people out there who are under the misconception that if LDL particles are large and fluffy or large and puffy enough they can't cause problems, that's totally inaccurate. Bottom line, when we're talking about LDL, particle count trumps everything.
Kaczor: Let's move on to HDL. That's really good points on the LDL because I do know that the size and the type, the fluffy or the dense, that idea is very much part of the verbiage that patients use when they come through the door-
Chong: I'm sorry, I will say one other thing quickly about that. I don't mean to say that it's worthless to check LDL particle size because it's still true that LDL particle size, the smaller the particles the higher the potential is for future risk, but it's not just because of the mechanism itself. It's like just because there is a strong relation between what causes LDL particle sizes small and what causes cardiovascular disease. As an example, typically people with poor insulin sensitivity, or insulin resistance, diabetes, et cetera tend to have smaller particles, so it's still important to look at particle size because it does add to the predictive value of the test you're running. I don't mean to say that it's worthless or anything like that, you just can't say, "If my particles are large and puffy, I don't care how many there are."
Kaczor: Got you. Okay. Let's go back and just come back to HDL, the high density lipoproteins. This we don't harp on as much, the drugs aren't targeted towards it as much. We tend to know that higher is better. How do you use HDL in your interpretations?
Chong: One of the reasons why the drugs aren't targeted as much is because they keep trying and failing. Pretty much every study that's ever been done on a drug that it raises HDL shows that they clearly work and then oftentimes the people die sooner, so they have to stop. The bottom line is it's not a cut and dry direct simple relationship where the higher the HDL the better necessarily. Especially if you make a change in somebody, so like diet, lifestyle, et cetera, and their HDL goes up it is absolutely not a guarantee that they are getting better or that they are more cardio protected than they were beforehand. It might be the case, but it's not a certainty.
From that perspective, at least personally, when I'm looking at HDL I'm always looking at the whole picture. If I see a relatively low HDL and yet this person might happen to be one of these lifelong naturally low in total cholesterol, naturally low in LDL people I'm not as concerned about that low HDL as I am in somebody who has really high LDL, really high total cholesterol, insulin resistance, et cetera, and they have low HDL. There's a definite difference.
Those two people might both have the same HDL number, but one is way more concerning than the other one, and it just has to do with the role of these particles, these molecules, and what are they doing for us? If you really simplify it down HDL does a lot of complicated things, we still don't even know everything that it does, but definitely one of its main job is reverse cholesterol transport where it's helping to remove excessive cholesterol deposited in the periphery so to speak. I like to look at it as a garbage truck or a garbage collector. It is very true that if you do have a lot of "garbage" in the system, you have a high total cholesterol, a high LDL there's lots of cargo, or garbage, or whatever you want to call it being shipped outward you would hope to see the body responding to that by increasing garbage truck count to pick up the extras.
You commonly see that on people who go onto low-carbohydrate, high-fat diets. Oftentimes you will see, hopefully, an elevation in HDL as the body is literally just adapting to the additional load on the system that you're putting on it. It does not, however ... Unfortunately, you can't take that response and then conclude that the low-carbohydrate diets are cardioprotective because they cause HDL to go up. It's not that cut and dry, it's more just that the body is responding and having to increase its HDL to adapt and make up for the extra amount of cholesterol in the system, if that makes sense.
It's quite complicated. You do see HDL go up for that reason. The other thing is sometimes you'll see high HDL in somebody who's got disease, especially if they're inflamed or they have chronic inflammation. In those situations, in all likelihood, what's going on is that inflammation is known to hinder HDL function. The body always trying to adapt, always doing the best that it can to deal with the cards it's being dealt, if it has poorly functioning HDL it's going to spit out more of them in an effort to continue doing the job that needs to be done. If the HDL are dysfunctional as a result of oxidative stress, inflammation, et cetera in the system if the person has the capability you may sometimes see HDL production go up or HDL number go up on the person's lab because each one is not working as well as it should.
Kaczor: That's an interesting idea, that it's a reaction.
Chong: Absolutely. It's a fluid, functional system. Again, people just think, "Oh, HDL went up, that's good," or whatever. It's not like that. You have to think about why is the body doing that? What is the response going on? The body's always trying to maintain homeostasis, which would include not having cholesterol collect in the walls of the arteries.
Kaczor: That's awesome. I appreciate that perspective. I think it's really helpful for us because we want the quickest most linear path to a conclusion, so it's good to remember to step back once in a while.
Chong: For sure.
Kaczor: We don't have time to go into labs, other labs in great detail, but what other laboratory parameters would you consider must haves? I'm going to give you a typical case, a patient comes to your office, they themselves have no history of cardiovascular disease. They have both sides lots of cardiovascular risk, so they believe that maybe there might be something going on there. What's your bare minimum of labs? What would you do?
Chong: Especially in today's world where we're not necessarily billing insurance or whatever personally, for me, if I'm trying to get the most bang for my patient's buck in the realm of cholesterol I'm going to measure an apo A1, or apolipoprotein A1, I'm going to measure an apolipoprotein B, which for those people that aren't fully aware it's essentially like getting more precise HDL and LDL. Apo A1 is like getting a bit more precise HDL count and apo B is like getting a more precise particle count. Again, that's the name of the game, especially looking at the ratio between those two.
I'm also going to measure a lipoprotein a, which has its own independent impact on things and is not necessarily going to be responsive to medications or dietary changes that do impact these other markers. It's a very important marker to assess and you can never really predict whether or not somebody's going to have high levels of that or not, but definitely the potential goes up with a strong family history.
Then, beyond that in the realm of inflammation I'm at least going to want to see an HSCRP, I'm at least going to want to do some fundamental blood sugar metabolism related markers. I personally like to check a fasting insulin, and then potentially a hemoglobin A1c as well, although that sometimes has some questionable value depending on each patient. Beyond that, it starts getting a little bit more spliced out and potentially, depending on each patient, what you might go from there. I do check vitamin Ds pretty often, I check ferritin, and iron binding capacity pretty often at least screening that once to make sure there's no hemochromatosis going on. Those are probably the main ones I'm going to want to see. I will definitely do a CBC as well.
Kaczor: The one I didn't hear you say, and I'm curious if you do, is homocysteine.
Chong: Sorry, thank you Dr. Kaczor. Yes, absolutely homocysteine as well. Again, whenever I have the opportunity especially if there is a strong history and there's good reason to want to delve more deeply than average there are definitely some other markers I would typically run with people, but those would be a great starting point.
I don't know if we're going to talk later about going outside of blood tests, but just long story short I don't consider an assessment truly complete without some type of imaging at least on the high risk population.
Kaczor: By that, you mean?
Chong: Sorry, carotid ultrasound, IMT, or a coronary calcium score.
Kaczor: I can vouch for that. I've had several patients with cholesterols that didn't look too impressive, but their coronary calcium scores came back very, very good, and so they didn't have any [inaudible 00:24:42].
Chong: I will say one pearl type of information about that, the value of coronary calcium scores specifically goes up with age. The value of risk assessment using that test goes up with age. In other words, occasionally if a person is still relatively young, typically under about 55, you may have a situation where that person has a decent amount of soft plaque that has not been calcified yet and it will make their calcium score looks pretty good, but then if you check a carotid ultrasound it doesn't look so good. I have seen some mismatches in that regard with some of the slightly younger people, so my tendency is to measure carotid ultrasound, IMT tests with the understanding, obviously, that you're not checking the coronary arteries, but there's an over 90% correlation between the two. To me, a carotid ultrasound is a little pickier, a little more fine-tuned than the other one, but absolutely the high calcium score is a very powerful risk predictor. It's just whether or not you're going to catch everybody that way.
Kaczor: Great. Dr. Chong, thank you so much for joining me today, I appreciate your expertise, taking the time. I think this is a to be continued type of thing because we didn't talk about what to do.
Chong: I would love to keep talking, yes because I feel like we just started scratching the surface. Happy to delve more into some of these other details because there's a lot of other things to consider.
Kaczor: We'll talk about treatments and we can talk a little bit more about imaging techniques next time. Thanks again.
Chong: Super, yeah. Thank you.