Triglycerides Linked to Risk for Heart Disease
High levels of triglycerides are strong predictors of cardiac trouble and this strengthens the case for including measurement of the blood fats in prevention programs, says a study in the Journal of the American College of Cardiology.
"Triglycerides traditionally have been viewed as second-class citizens," says lead author Dr. Michael Miller, at the University of Maryland Medical Center.
"LDL cholesterol has always taken center stage," says Dr. Miller. "We know that LDL is intimately involved in bringing cholesterol to scavenger cells, which deposit them to form plaques in the arteries.
"This study shows that triglycerides in and of themselves are also lipids to blame," notes Dr. Miller.
The original study was designed to test the effectiveness of two LDL-lowering statins called Pravachol® and Lipitor® in reducing recurring coronary disease after a heart attack.
The new study went over the data on the 4,162 participants in the trial, looking at the association between triglyceride levels and the incidence of heart problems and death.
"The patients who had heart attacks came back after 30 days," says Dr. Miller. "We measured LDL levels and triglyceride levels and followed them over the next two years, evaluating for the occurrence of new events and death. If a patient had triglyceride levels below 150 [milligrams per deciliter], there was a 27 percent lower risk of having a new event over time," he says.
"After multiple adjustments for such things as age, diabetes, high blood pressure, and obesity, the risk reduction was 20 percent," Dr. Miller explains.
Unlike LDL cholesterol, for which there is a recommended blood level of 70 or below, there is no recommended blood triglyceride level but 150 milligrams per deciliter or below is "considered as desirable," says Dr. Miller.
When the participants were divided into four groups on the basis of both LDL and triglyceride levels, those in the group with under 150 for triglycerides and under 70 for LDL did the best.
They had a 28 percent lower risk than those in the group with the highest readings for both LDL and triglycerides, he says.
"At the present time, we don't have a recommendation for triglyceride lowering, so the next logical step is a study to determine whether lowering triglycerides and LDL reduces risk more than lowering LDL alone," he says. Two such studies are in progress, he notes.
Previous research has already pointed toward such a connection: A study that appeared in the medical journal Neurology last December found a link between triglycerides and stroke risk.
And research published in the Journal of the American Medical Association (JAMA) last July showed that when high triglyceride levels showed up in nonfasting cholesterol tests, there was an increased risk for a future heart attack.
Dr. Leslie Cho of the Women's Cardiovascular Center at the Cleveland Clinic, notes that the new report "is not a huge surprise."
She says, "The unique thing about this study is that even if you control bad LDL cholesterol to less than 70, you still need to look at triglycerides."
The problem with triglycerides is that "they are the most unstable fats in the body," so that at least two readings are needed to get an accurate measure of blood levels, she explains.
Dr. Miller says, "I am proactive about both LDL cholesterol and triglycerides."
Several measures can be taken to lower triglyceride levels - many of them are already recommended on general principles for reduction of coronary risk.
One is to eat a Mediterranean diet, rich in fish. Omega-3 fatty acids can lower triglyceride levels, as can niacin, and exercise has a beneficial effect, says Dr. Miller. Statins also have some triglyceride-lowering effect, he notes.
"If you can effectively get both LDL cholesterol and triglycerides down, you are going to do better," says Dr. Miller.
Always consult your physician for more information.
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Cholesterol is a waxy substance that can be found in all parts of your body. It aids in the production of cell membranes, some hormones, and vitamin D.
The cholesterol in your blood comes from two sources: the foods you eat and your liver. However, your liver makes all of the cholesterol your body needs.
Cholesterol and other fats are transported in your blood stream in the form of spherical particles called lipoproteins. The two most commonly known lipoproteins are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
LDL (low-density lipoprotein) cholesterol
This type of cholesterol is commonly called the "bad" cholesterol, and is a type of fat in the blood that contains the most cholesterol. It can contribute to the formation of plaque buildup in the arteries, known as atherosclerosis.
You want your LDL to be low. To help lower it:
- avoid foods high in saturated fat, dietary cholesterol, and excess calories
- exercise
- maintain a healthy weight
- stop smoking
HDL (high-density lipoprotein) cholesterol
This type of cholesterol is known as the "good" cholesterol, and is a type of fat in the blood that helps to remove cholesterol from the blood, preventing the fatty buildup and formation of plaque.
You want your HDL to be as high as possible. Some people can raise HDL by:
- exercising for at least 20 minutes three times a week
- kicking the cigarette habit
- avoiding saturated fat intake
- decreasing body weight
For others, medicine may be needed. Because raising HDL is complicated, you should work with your physician on a therapeutic plan.
Triglycerides are another class of fat found in the bloodstream. The bulk of your body's fat tissue is in the form of triglycerides.
The link between triglycerides and heart disease is under clinical investigation. However, many people with high triglycerides also have other risk factors such as high LDL levels or low HDL levels.
Elevated triglyceride levels may be caused by medical conditions such as diabetes, hypothyroidism, kidney disease, or liver disease.
Dietary causes of elevated triglyceride levels may include obesity and high intakes of fat, alcohol, and concentrated sweets. A healthy triglyceride level is less than 150 mg/dL.
Always consult your physician for more information. |