Hypercholesterolemia is a disorder characterized by high levels of blood cholesterol. Cholesterol is manufactured primarily in the liver and then carried to the cells throughout the body by low-density lipoprotein (LDL). Because cholesterol and other fats do not dissolve in water, they cannot travel through the body unaided. Lipoproteins are particles formed in the liver to transport cholesterol and other fats through the bloodstream. Cholesterol is returned to the liver from other body cells by another lipoprotein, high-density lipoprotein (HDL). From there, cholesterol is secreted into the bile, either unchanged or after conversion to bile acids.
Cholesterol is essential for the formation of cell membranes and the manufacturing of some hormones, but it does not need to be ingested as part of a regular diet. In fact, the body�s liver produces all the cholesterol it needs on its own. If blood cholesterol levels are elevated, large amounts of LDL (so-called �bad�) cholesterol deposit in the arterial walls. These deposits represent the first stage of atherosclerosis, or narrowing of the arteries. Because hypercholesterolemia causes no symptoms, preventive measures and regular measurement of cholesterol levels are important for people in high-risk categories.
Hypercholesterolemia is especially dangerous when HDL (�good�) cholesterol levels are low. Left untreated, hypercholesterolemia can eventually lead to a heart attack due to coronary artery disease or a stroke due to narrowed arteries supplying the brain.
When to Call Your Doctor
Make an appointment with your doctor to check your cholesterol levels if you are at high risk for coronary artery disease or if any member of your immediate family has hypercholesterolemia.
Unfortunately, the only symptoms (angina, heart attack, stroke) result from the complications of high cholesterol. When cholesterol levels are very high, cholesterol may be deposited as yellow nodules (xanthomas) in tendons or just beneath the skin under the eyes.
Hereditary factors are the most common cause of high cholesterol. A diet high in saturated fat and cholesterol can also increase blood cholesterol levels. Other disorders, such as diabetes mellitus, Cushing�s syndrome and hypothyroidism, may promote hypercholesterolemia.
Eat a diet low in saturated fats and cholesterol. A diet rich in water-soluble fiber tends to lower blood cholesterol. Exercise regularly, and try to lose weight if you are more than 20 percent overweight. Drink alcoholic beverages in moderation (no more than two a day). Moderate alcohol consumption raises levels of beneficial HDL cholesterol; however, consumption of more alcohol than this amount can have harmful effects.
Hypercholesterolemia, or high cholesterol, is one of several conditions managed by doctors with The Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, directed by Dr. Roger Blumenthal. Our physicians specialize in managing adults who are at high risk for future cardiovascular disease either because of risk factors such as hypertension, diabetes, high cholesterol, cigarette smoking, or sedentary lifestyle, or because of a known family history of heart disease or peripheral vascular disease.
Our personalized, comprehensive approach to lifestyle and medical management can slow the progression of cardiovascular disease and decrease one�s future risk of heart attack, stroke, bypass surgery or angioplasty. We also sponsor research that includes both clinical trials and basic molecular studies.
During your evaluation for high cholesterol, a Johns Hopkins cardiologist will examine you at our Outpatient Center or satellite facility in Green Spring Station, Maryland
- The main diagnostic test for high cholesterol is a blood test to measure levels of total cholesterol, which includes high-density lipoprotein (HDL) or �good� cholesterol, low-density lipoprotein (LDL) or �bad� cholesterol, and triglycerides (fats). The test also examines nontraditional risk factors, substances such as homocysteine, hs-CRP (C-reactive protein), Lipoprotein (A), ApoB (apoprotein B).
- Depending on your family history, your doctor may also recommend that you get a coronary artery calcium scan. The Green Spring Station location is affiliated with HeartSavers, a group that uses electron beam computed tomography (EBCT) to take up to 40 pictures of the heart between beats while patients remain fully clothed. Images from the five-minute test show early calcium buildup, or plaque, which appear as white specks in the walls of arteries. Doctors will compare the amount of coronary calcium present to what would be expected for your age and gender.
A significant contribution to the treatment of high cholesterol was the 1980 discovery of hyperapoB by Drs. Sniderman and Kwiterovich at the University Lipid Clinic and Lipid Research Atherosclerosis Division. Many patients with coronary artery disease (CAD) have an increased number of small low-density lipoprotein (LDL) particles that are missed by the standard cholesterol or LDL cholesterol testing. In patients with hyperapoB, it may not be clear why they have developed CAD since the LDL cholesterol may be �normal.� Such patients respond to drug therapy. A low-fat diet is also important since they have a delayed clearance of the post-prandial atherogenic chylomicron remnants from their blood.
HyperapoB was discovered by the use of the blood test for apolipoprotein B levels. The apoB levels are elevated, despite a normal total or LDL cholesterol. The apoB test is available at the University Lipid Clinic and is performed in the Johns Hopkins Analytical Laboratory. The same laboratory performed the analyses for the national NHANES (National Health and Nutrition Survey). This is also the laboratory that determined the normal ranges for all ages and both genders.
In addition, hypercholesterolemia, or high cholesterol, is one of several conditions managed by doctors with The Johns Hopkins Ciccarone Center for the Prevention of Heart Disease.
Treatment for hypercholesterolemia might include lifestyle changes such as adopting a healthy diet and increasing your level of physical activity. Our nurse health educators specialize in helping people to improve their lifestyle habits. Johns Hopkins has an excellent cardiac rehabilitation program and clinical exercise program at Johns Hopkins Heart Health. Lifestyle changes alone are frequently all that is necessary.
You may be prescribed medications designed to reduce blood cholesterol levels, such as statins or resins. Other agents used include fibric acid derivatives (which decrease the liver�s production of triglycerides, nicotinic acid) and new medications such as ezetimibe, a cholesterol absorption inhibitor.
Your doctor will determine which course of treatment will most benefit your condition.