Dr. Paul D. Thompson, MD, explains HDL, LDL, triglycerides, and lipoprotein(a). He discusses why a family history of early heart disease can matter even when routine cholesterol results appear reassuring.
Understanding Cholesterol Results: HDL, LDL, Triglycerides, and Lipoprotein(a)
Jump To Section
- HDL cholesterol and very high levels
- Triglycerides and apolipoprotein B
- LDL cholesterol and arterial damage
- Lipoprotein(a) and family history
- Lowering LDL when lipoprotein(a) is elevated
- Full Transcript
HDL cholesterol and very high levels
Cholesterol results include different measurements with different implications. In his conversation with Dr. Anton Titov, MD, cardiologist Dr. Paul D. Thompson, MD, uses the film-inspired description of the good, the bad, and the ugly to distinguish them. He begins with high-density lipoprotein cholesterol, usually abbreviated HDL.
HDL is the measurement he calls good cholesterol, but he adds an important qualification. He describes a U-shaped relationship with heart-disease risk: risk falls as HDL rises through part of the range, then rises again at very high levels. His explanation therefore does not treat an increasingly high HDL result as unlimited reassurance.
Triglycerides and apolipoprotein B
Triglycerides are the next measurement Dr. Thompson discusses. He calls them the bad part of his comparison and identifies them as a risk factor for heart disease. His explanation focuses on the particles that carry triglycerides, which also carry apolipoprotein B, or ApoB.
That particle-based explanation connects a familiar blood-test result with the discussion of cholesterol transport. Dr. Thompson then contrasts triglycerides with LDL, which receives the strongest emphasis in his account of arterial damage.
LDL cholesterol and arterial damage
LDL stands for low-density lipoprotein cholesterol. Dr. Thompson calls it the ugly cholesterol in his analogy, describing it as the cholesterol that enters arteries and causes the most damage. Lowering LDL becomes the central treatment theme of this segment.
However, he warns against stopping the assessment with these familiar measurements. His discussion introduces another particle, lipoprotein(a), that can alter how reassuring an otherwise ordinary cholesterol result appears.
Lipoprotein(a) and family history
Lipoprotein(a), often shortened to Lp(a), is largely genetically determined, according to Dr. Thompson. He explains his interest through the example of a person aged 40 whose father had a heart attack at 45. If the father did not smoke and did not have diabetes, the family history would attract his attention even when the person's cholesterol results looked relatively good.
Dr. Thompson says this pattern led him to find elevated lipoprotein(a) in some patients with a concerning family history. He urges clinicians not to dismiss those concerns simply because routine cholesterol levels do not look particularly high. His advice in the interview is to measure lipoprotein(a) before offering that reassurance.
Lowering LDL when lipoprotein(a) is elevated
Lowering LDL is Dr. Thompson's practical focus when lipoprotein(a) is elevated. He describes evidence and clinical thinking that bringing LDL very low can reduce the danger associated with the additional particle. This is his explanation of a treatment approach, not a promise that an individual patient's inherited risk disappears.
He closes by discussing the role of medication. In his experience, appropriate medication makes a substantial LDL reduction easier to achieve than a very restrictive diet alone. The segment explains his reasoning rather than naming a particular prescription or setting an individual treatment target.
Full Transcript
Dr. Anton Titov, MD: What do my cholesterol numbers - LDL, HDL, and triglycerides - actually mean?
Dr. Paul D. Thompson, MD: Let me tell you what your cholesterol is. I call them the good, the bad, and the ugly. Not the movie with Clint Eastwood, but just good, bad, and ugly cholesterol levels.
Dr. Paul D. Thompson, MD: What is the good cholesterol level? The good cholesterol is called high-density lipoprotein cholesterol, or HDL. Believe it or not, HDL is one of the most powerful predictors of what is going to happen to you.
Dr. Paul D. Thompson, MD: If you have a high level of the good cholesterol, you reduce your risk of heart disease. That comes with a caveat, a little bit of a disclaimer, because once your HDL cholesterol, the good cholesterol, gets above about 80, then, believe it or not, the risk starts to go up. It is what we call a U-shaped curve.
Dr. Paul D. Thompson, MD: The risk comes down and then it starts going up when you get to the other end. It comes down all the way to about 80. As your HDL cholesterol level goes up, your risk of heart disease goes down.
Dr. Paul D. Thompson, MD: Once you get above 80, it starts to go up again. That is the good cholesterol level. Then there is what I call the bad cholesterol level.
Dr. Paul D. Thompson, MD: That is triglycerides. Triglycerides are a risk factor for heart disease. They are a risk factor for heart disease because the particle that carries them carries something called ApoB.
Dr. Paul D. Thompson, MD: ApoB is part of that particle, apolipoprotein B. Triglycerides are a risk factor, but they are not as strong as what I call the ugly cholesterol. The ugly cholesterol is LDL cholesterol, low-density lipoprotein cholesterol.
Dr. Paul D. Thompson, MD: That is the one that gets into your arteries and does the most damage. But that is not the full story. It is not just the good, the bad, and the ugly; there is another particle that we need to talk about, another type of cholesterol.
Dr. Paul D. Thompson, MD: That is called lipoprotein(a). Lipoprotein and then a parenthesis and an A in the middle of it. Lipoprotein(a) is a type of ugly cholesterol.
Dr. Paul D. Thompson, MD: It is a type of LDL cholesterol that takes any cholesterol level you have and raises your risk a lot. I got interested in the 1970s because I would see people who came in to me and said, "I am worried about myself. I am worried about myself because I am 40."
Dr. Paul D. Thompson, MD: "My dad had a heart attack at 45. I want to make sure I am not going to be like him." I always say, "Did your dad smoke?"
Dr. Paul D. Thompson, MD: "No, he did not smoke." "Did he have diabetes?" "No, he did not have diabetes."
Dr. Paul D. Thompson, MD: Now I am paying attention. What we often found was that those people who had relatively good cholesterol levels and yet a bad family history of heart disease often had that lipoprotein(a). When I lecture about this to doctors, I say: before you give false reassurance, before you say to a patient who is worried, "Forget about it; your cholesterol levels are not that bad."
Dr. Paul D. Thompson, MD: Before you give false reassurance, what you should do is measure lipoprotein(a), and if the lipoprotein(a) is elevated, that is a problem. What do you do about lipoprotein(a)? Again, it is that whole thing about picking the right parents, because it is largely genetically determined.
Dr. Paul D. Thompson, MD: What we have shown and what people believe is that if you get your overall ugly cholesterol level very low, if you get the LDL very low, then the bad thing, the bad particle we have talked about, the lipoprotein(a), is no longer as dangerous. There is the good, the bad, the ugly, and then there is lipoprotein(a). The way to handle all these things is to get your cholesterol level low.
Dr. Paul D. Thompson, MD: As I always say to patients, I am a drug dealer. Legal drugs, nothing illegal, but I am a drug dealer because it is easier to get your LDL cholesterol level down with the right medications than it is to have you torture yourself with a diet that is very, very strict. Even that very strict diet will not get you to where you want to go.