After a routine medical exam which is completely normal, Sam goes for some routine blood tests, including cholesterol levels. A week later he’s asked to come into the doctor’s office to discuss the test results. It turns out Sam’s cholesterol levels are high.
Next thing he knows, the doctor is asking him all kinds of questions about his diet and lifestyle. The doctor suggests a strict low fat diet, refers him to a dietitian, and wants to test his cholesterol levels in three months. Sam is told that he may need to start on medication if his levels are still high at that time! Does this story sound familiar? What is all the fuss about?
As you probably know, heart disease and stroke are the number one killers of North Americans. About half of first-time heart attacks are fatal. The large number of people who die of their first heart attack aren’t even aware they have the disease. Heart attacks occur primarily because of a gradual clogging of the coronary arteries. These are the arteries that supply blood to the heart. Many factors are involved in this process, called atherosclerosis or “hardening of the arteries.” The link between high levels of fatty substances in the blood and atherosclerosis was established nearly 80 years ago.
Cholesterol and triglycerides are the major fatty substances in the bloodstream. Triglycerides are used by muscle and fatty tissue to store energy. Cholesterol is an essential part of all cell membranes, such as skin, hair and muscle cell membranes. It is also a major component part of bile (used for digestion of fatty foods) and of several important hormones, including sex hormones.
Triglycerides and cholesterol are transported in your bloodstream inside bubble-like structures called lipoproteins. Lipoproteins are like bubbles of grease with a protein coating.
When your doctor checks your cholesterol levels, he is looking at the levels of triglycerides and lipoproteins in your blood. There are two kinds of lipoproteins. Low density lipoprotein (LDL) is known as “bad cholesterol” and high density lipoprotein (HDL) is known as “good cholesterol.” LDL is involved in distributing cholesterol to the body via the bloodstream. HDL is involved in taking cholesterol out of the bloodstream. So you can think of LDL as the “grease-spiller” and HDL as the “grease-absorber.”
A certain amount of cholesterol and triglyceride is necessary for the body to work normally. However, too many fatty substances in the blood can lead to hardening and clogging of the arteries. This increases the person’s risk of having a heart attack or stroke. People with low levels of HDL (the grease-absorber), high levels of LDL (the grease-spiller) or triglycerides are considered to have dyslipidemia, an abnormal level of fatty substances in the blood.
There are two major types of dyslipidemia. Primary dyslipidemia occurs when a person is born with a genetic problem involving the processing of fatty substances in the bloodstream. This rare but important kind of dyslipidemia tends to affect young people.
The more common type is secondary dyslipidemia. Here the basic processing of cholesterol and triglycerides is normal, but an outside factor has disturbed the process. Some medications (some blood pressure medications, birth control pills and steroids) can cause dyslipidemia. Diseases including diabetes, under-active thyroid gland, obesity and kidney disease can also cause dyslipidemia.
However, bad eating habits are the major cause of dyslipidemia in North America. Too many calories, too much saturated fat, high alcohol intake, and weight gain cause most of the problems with cholesterol and triglyceride levels in our society. Here, it is much more common to have a high LDL (bad cholesterol) level than a high triglyceride level.
‘Normal’ cholesterol and triglyceride levels depend on your age and whether you have any other medical conditions. What is normal for a 24-year-old healthy man may not be considered normal for a 62-year-old woman who has diabetes. Also, high HDL (good cholesterol) levels protect you against heart disease. So, the amount of total cholesterol compared to the amount of good cholesterol is also important.
If you do have dyslipidemia, your doctor will try to figure out your risk profile. Certain risk factors make you more likely to have a heart attack or stroke. They include diabetes, high blood pressure, smoking, obesity, age and whether you have any close (first-degree) relatives with heart disease. Men older than 45 and women older than 55 are at higher risk of heart disease than the rest of the population. Based on your risk factors, your doctor can decide what cholesterol and triglyceride levels are normal for you and what needs to be done about them.
Acceptable cholesterol and triglyceride levels depend on your individual risk factors.
If your triglycerides are high, your doctor usually recommends that you drink less alcohol, exercise more and try to lose some weight. There are some medications available to lower triglyceride levels but generally they are not as effective as lifestyle changes.
If your LDL (bad cholesterol) levels are high and you have no other medical problems, your doctor will begin by recommending lifestyle changes - exercising more and trying to lose weight. If you smoke or drink lots of alcohol, you will need to cut down or quit. The idea behind lifestyle changes is not only to improve your cholesterol levels but to decrease your other risk factors for heart disease. You will need to change your diet, reducing total fat, saturated fat and cholesterol, and increasing fibre. Most doctors will send you to a dietitian for detailed dietary advice.
To see how effective the changes you make are, you will have your lipid levels checked again in three months. If you still have dyslipidemia, you and your doctor will make a joint decision as to whether you should try a stricter diet or go on medication.
Today there are some very effective medications for lowering LDL levels. The medications may cause side effects such as stomach upset, muscle aches and liver irritation. Your doctor will monitor you to keep these side effects under control. As well, appropriate blood tests will be done to be certain that liver damage is avoided.
As you know, healthy eating, more exercise and quitting smoking benefits you in more ways than just improving your cholesterol levels. Most doctors prefer not to give you medication if you are able to make the needed dietary and lifestyle changes. However, if these don’t work, medications will be necessary to protect you against heart disease.
When diagnosed with dyslipidemia, many people will say that they feel just fine and don’t think they need to be on medication. Remember that treating dyslipidemia is just like treating high blood pressure. It falls into the category of preventive health care. Again, 50 per cent of first time heart attacks are fatal. Doesn’t it make sense to prevent some of these? We have the means to do so.