Lab Values, part 13: Low-Density Lipoprotein (LDL) & High-Density Lipoprotein (HDL)

Hi, I'm Meris, and in this video, I'm going to be talking to you about low-density lipoprotein, LDL, and high-density lipoprotein, HDL. Let's go ahead and get started.

So first up, we're going to talk about low-density lipoprotein, or LDL. And this is a really important molecule in our body because it's used to transport cholesterol. And if you want a review of cholesterol, go look at the last video. But this molecule helps get cholesterol from the foods that we eat to wherever it's going in the body. It's super important that we have that to transport. But again, we don't want to have too much LDL. If we have too much LDL, we will end up with a buildup of cholesterol in the arteries, which we call plaque. Again, this is when cholesterol combines with other molecules, such as this transporting lipoprotein, and it creates this big fatty globule that's going to get stuck somewhere in my arterial circulation, increasing my blood pressure and increasing my risk for many different things.

So what do I want my value to be? As you might be able to think, this is a lab value where I want it to be a little bit lower than you might expect because I don't want it to be combining with cholesterol and creating plaque. So I need to make sure that this is on the lower end. So again, this is one where there's not a high and low and an expected range. We just say we want it to be less than 130 milligrams per deciliter. So there's also a very important thing that I want to point out though, which is that it's not enough for us to just say that we want this one to be less than 130. If your patient is at a high risk for cardiovascular disease, maybe that's due to their lifestyle and their diet and their personal risk factors, maybe that's due to a significant family history, but for whatever the reason, if your patient is at an increased risk for cardiovascular disease, we actually want them to aim to have a level that is less than 100 milligrams per deciliter.

Again, remember, we are talking about a range. I mean, it could go from the bottom all the way up to 130, but I'm going to try to shift that a little bit for this patient who is at high risk because I know, as a good nurse, that if my patient's cholesterol is above that, even when it's still within that normal limits, that's giving them some extra risk for plaque buildup. The lower we can get it, the better. And of course, we're going to do that through a heart-healthy diet and exercise and other lifestyle modifications. You can go watch some of our other nursing videos for that content.Now, we do have a cool chicken hint here to help you remember, which is that L for low-density lipoprotein is also lethal, and we want it to be low. So LDL is lethal and low.

Now, what if we have elevated LDL above 130 milligrams per deciliter? Well, this is going to indicate that our patient is at an increased risk for atherosclerosis. So again, those plaque buildups in the arteries, heart disease of any variety, coronary artery syndrome, whatever you might be thinking of, myocardial infarction, heart attack, and then also things like elevated blood pressure, hypertension, strokes, and many other things. But that heart-healthy relationship is really important to keep in mind.

Now, let's transition and talk about HDL. Now, HDL is high-density lipoprotein. So this one has actually a very different job. It's super important. It's actually going to transport that cholesterol from wherever it is in the body back to the liver for the liver then to get rid of it, to process that cholesterol and remove it from the body. So this one, if you think about it in comparison, do I want this one to be low? No, I want this one to be higher because in this case, this is a good cholesterol. This is a lipoprotein that's going to help to remove the cholesterol from my body so that I don't end up with that plaque buildup. So I really want it to be elevated. This again has to do with the sex assigned at birth. So for women, we want this level to be greater than 55 milligrams per deciliter. And for men, we want it to be greater than 45.

Again, this just has to do with the chemical composition of our bodies and the different ways of fat distribution, muscle, and all of these things. But the point here is that there's no between these numbers. It's just we want it to be higher than a given set point. Luckily though, we have a cool chicken to help you remember that, too, which is that HDL, starting with an H, is healthy, and we want it to be high. So you put it all together, LDL is lethal and low. HDL is healthy and high, okay?

Now, what if I have decreased HDL levels? Well, it's going to put me at increased risk for heart disease, right? If I don't have enough HDL to get my cholesterol out of my body, then I'm at an increased risk for heart disease. So that's the thing that's important to know there is that we're going to educate our patients that we want that LDL to be as low as we can, and we want that good cholesterol, the HDL, to be high, and explain why. This is going to help remove plaque from your body. This is going to keep you from getting those clogged arteries, right?

All right. I'm so glad you stayed until the end because I'm going to test your knowledge of key facts provided in this video with some quiz questions.

The patient correctly verbalizes their understanding of their recent lab results when they tell the nurse that they will exercise more and eat a heart-healthy diet to try and increase which lipoprotein?

High-density lipoprotein or HDL.

A patient asks the nurse what LDL level he should be aiming for given that he is at high risk for cardiovascular disease. How should the nurse respond?

Less than 100 milligrams per deciliter.

All right. That is it for this video. Thank you so much for watching. I really hope you learned something. All right. I'll see you in the next one. Thanks so much and happy studying.