Cholesterol is the waxy substance your body uses to make cell tissues, protect nerves and produce hormones. Lipoproteins transport cholesterol in the body. High-density lipoproteins absorb cholesterol and transport it to the liver to break it down and remove it from your body. Low-density lipoproteins, or LDL, carry cholesterol to other parts of the body. Having high levels of LDL cholesterol puts you at risk for atherosclerosis, coronary artery disease, and heart attack. Testing for LDL cholesterol levels can help physicians evaluate your risk of developing heart disease.
LDL and LDL Subtypes
Your liver makes all the cholesterol your body needs to appropriately maintain cholesterol-driven bodily functions. You also get cholesterol from foods you eat, and consuming high-cholesterol foods can cause excess cholesterol in the blood. LDL helps transport cholesterol, triglycerides and fats to various parts of the body. LDL particles vary in size and density. Having smaller, denser particles, known as pattern B, is associated with an increased risk of coronary heart disease compared to having larger and less dense LDL particles, known as pattern A, according to the University of Missouri's Virtual Health Care Team.
LDL Cholesterol Scores
Physicians commonly evaluate your risk of heart disease by testing your LDL cholesterol along with triglycerides, HDL cholesterol and total cholesterol. Ideally, you should have a LDL cholesterol level of less than 100 milligrams per deciliter, or mg/dL, especially if you have had a coronary event or have heart disease. LDL cholesterol levels of 100 to 129 mg/dL are still within acceptable limits and pose limited risk. Test results that range between 130 and 159 mg/dL are borderline high, according to Lab Tests Online. Once your levels reach 160 to 189 mg/dL, you fall into the high risk category for heart disease. Anything over 189 mg/dL is very high risk and your physician will probably recommend some life changes to help you lower your risk.
Alternative Cholesterol Tests
Laboratories determine LDL cholesterol scores by applying a formula to total cholesterol, HDL levels and triglycerides. However, when people have extremely elevated levels of triglycerides, this invalidates the formula and laboratories must determine LDL levels through a test known as direct LDL cholesterol. Attempts to understand how LDL cholesterol levels affect heart disease risk have led scientists to look for newer, more specific tests. The National Heart, Lung and Blood Institute recently completed a clinical trial evaluating the use of LDL subtypes, such as pattern B, to identify people at higher risk of heart disease, though the results of the study are still pending.
Significance
LDL cholesterol poses a risk to your health because these particles can transport cholesterol into the arterial walls, especially pattern B LDL, notes the American Heart Association. Once there, the particles can attract macrophages. Macrophages are white blood cells in tissues that play a significant role in clearing out cellular debris and regulating immune response. Macrophages engulf the LDL particles and begin to form plaque under the arterial walls. These plaques can rupture, activate clotting and cause arterial narrowing, which can lead to stroke, heart attack or peripheral vascular disease.
Considerations
You should always undergo cholesterol screenings when in good health. Surgery, trauma, rapid weight gain or loss and even pregnancy can affect LDL cholesterol levels.
