Ask the Expert: The Truth About Cholesterol

Dr. David Ostrander, a cardiologist and specialist affiliated with Sharp, answers questions about cholesterol.

What is cholesterol?
Cholesterol is a fat. Cholesterol is carried in the blood in different packages that we call lipoproteins.

What are the different types of cholesterol?
The low-density package, the LDL, is the package that actually causes cholesterol to be deposited in the wall of arteries. Whereas the HDL, or the high-density package, is like a recycling system: It’s like a garbage truck that takes cholesterol back from the vessel wall to the liver, where it can be recycled.

Why do patients need to watch their cholesterol?
People who have lower amounts of cholesterol in the bad package and higher amounts in the good package, are at a lower risk for heart attack and stroke.

Why is high cholesterol so worrisome?
People who have high levels of LDL and low levels of HDL are at an increased risk for heart attack and stroke. Typically, people with total cholesterol levels of 350 or 400, often have heart attacks in their 30s. The risk depends on the company it keeps. So a high cholesterol in somebody who also has diabetes is more serious. A high cholesterol in somebody who also smokes is more serious. A high cholesterol in somebody who also has high blood pressure is more serious.

How do I know if my cholesterol is a problem?
It’s easy to find out if you have a problem. You can ask your doctor to send you to the lab to have blood drawn, to measure your total cholesterol, your bad cholesterol, and your good cholesterol.

Is there a perfect number for my cholesterol?
People talk about this 200 number, which refers to the total cholesterol level; certainly we would like that to be under 200. And, as we break it down, we would like the bad cholesterol to be under 160 for people who have no risk factors, no other risk factors for heart trouble; under 130 for people who have additional risk factors like high blood pressure for example and under 70 for people who have established heart trouble or who have diabetes. So the target really depends on your level of heart attack risk.

Do genetics affect these levels?
If someone has a very strong family history of early coronary disease, or has a known family history of very high cholesterol levels, that person should probably have measurements made, even as a teenager. The individual, on the other hand, who has a family history of longevity, who has an ideal blood pressure, who has no diabetes, doesn’t smoke cigarettes, exercises everyday and is thin, for that individual it’s probably fine to get their first cholesterol measurement in their 40s or 50s.

What else is a factor?
People with certain inherited conditions have very, very high levels of cholesterol, but for most people, lifestyle is just as important as their genetics in determining their cholesterol level. And so what they eat, the amount they eat, the amount of exercise they do, very much influences their cholesterol.

What can I do to better my cholesterol?
Exercising every day can have a very powerful beneficial effect on raising the level of good cholesterol. Drinking a modest amount of alcohol raises the good cholesterol.

Do my stress levels matter when it comes to my cholesterol?
Stress, undoubtedly, is an important factor in determining who gets a heart attack, and when. Its effect on the cholesterol probably is not quite so important. 

How do past health events play a part in my cholesterol levels?
If you’ve already had a problem, you’ve had a heart attack, you have blocked arteries in your legs, blocked arteries in your neck. You already have established blood vessel disease and you’ve had some clinical event like chest pain or heart attack or you can’t walk because of leg pain. For those individuals, treating high cholesterol pays huge dividends. On the other hand, there are lots of people who just have high cholesterol and haven’t had any clinical problem, don’t have any known vascular disease, and in those people, lowering cholesterol is much less beneficial because their risk of an event is much lower. 

How can this be tested?
Some of us advocate imaging studies to determine if you already have the early stages of vascular disease, to determine whether you should be on treatment. So, for example, we can do a scan of the heart to see if there is calcium in your coronaries. We’re using very fast CT scans to see if there’s actually a build-up of plaque. And in an individual who has high cholesterol but no symptoms, but already has cholesterol deposits in their arteries, many of us would argue that that patient should be treated very aggressively because their body is telling us that they are destined to have a problem and we don’t want to wait for that problem to happen to start them on treatment.

What should I do if I'm concerned for my health?
I think that patients should talk to their doctor with whom they have the best relationship and who’s interested in discussing the topic. It could be your family doctor, it could be your internist, it could be a nurse practitioner, or it could be a cardiologist. There are a lot of health care professionals with a good deal of knowledge in this. I think crucial to it is that you have a health care provider who is interested in sitting down with you and having a discussion, and talking about some of the nuances of cholesterol, whether you should be treated, certainly how lifestyle impacts cholesterol, and things that you should be doing to live healthfully.

For More Information
For more information about heart and vascular care at Sharp or to find a Sharp-affiliated doctor, search for a San Diego cardiologist or call 1-800-82-SHARP (1-800-827-4277), Monday through Friday, 8 am to 6 pm. To find general information about heart and vascular care, visit Cardiovascular Diseases in Adult Health or read the Heart and Cardiovascular News archive.