High Blood Cholesterol
Lipid disorders are when you have excess fatty substances in your blood. These substances include cholesterol and triglycerides. Having a lipid disorder makes you more likely to develop atherosclerosis and heart disease.
Lipid disorders; hyperlipoproteinemia; Hyperlipidemia; Dyslipidemia
Cholesterol can be bound to fat and protein at different densities. Two main types include:
- Low-density lipoproteins (LDL) -- bad cholesterol
- High-density lipoproteins (HDL) -- good cholesterol
In general, you want your LDL to be LOW, and your HDL to be HIGH.
High cholesterol and other lipid disorders can be inherited (genetic) or associated with:
- Fatty diets
- Diabetes, hypothyroidism, Cushing's syndrome, and kidney failure
- Certain medications, including birth control pills, estrogen, corticosteroids, certain diuretics, and beta-blockers
- Lifestyle factors, including habitual, excessive alcohol use and lack of exercise, leading to obesity.
People who smoke and also have high cholesterol are at even greater risk for heart disease. Lipid disorders are more common in men than women.
There are no symptoms.
Exams and Tests
A fasting lipid test (lipoprotein test) breaks down cholesterol into four groups:
- Total cholesterol
- Low density lipoproteins (LDL) -- bad cholesterol
- High density lipoproteins (HDL) -- good cholesterol
In general, a total cholesterol value over 200 mg/dL may indicate a greater risk for heart disease. However, LDL levels are a better predictor of heart disease and determine how your high cholesterol should be treated.
How you are treated also depends on whether you have any of these additional risk factors for heart disease:
- Poorly controlled high blood pressure
- Currently smoke
- Being male and over age 45 or female and over age 55
- Having a first-degree female relative diagnosed with heart disease before age 65 or a first-degree male relative diagnosed before age 55.
- Metabolic syndrome (high triglycerides, low HDL, and obesity)
Discuss your results with your health care provider to determine the best therapy for your lifestyle.
Other tests to help determine your risk for heart disease are:
- Lipoprotein(a) analysis
- C-reactive protein analysis
Laboratory tests may be performed to identify secondary causes of lipid disorders if a lipoprotein test is elevated.
There are several types of lipid lowering drugs. Some are better at lowering LDL cholesterol, some at reducing triglyceride levels and some help raise HDL cholesterol, the good cholesterol.
Statins are also known as HMG-CoA reductase inhibitors. They are the most effective drugs in lowering LDL cholesterol. They inhibit HMG-CoA reductase (3-hydroxy-3-methylglutaryl coenzyme A reductase) an enzyme involved in the synthesis of cholesterol, especially in the liver. Decreased cholesterol production leads to an increase in the number of LDL membrane receptors, which increases clearance of LDL cholesterol from circulation.
|Brand Name||Generic Name|
|Baycol (withdrawn August 2001)||cerivastatin|
Fibrates are regarded as broad-spectrum lipid lowering drugs. Their main action is to decrease triglyceride levels but they also tend to reduce LDL cholesterol and help to raise HDL cholesterol. Mechanism of action is not well established. Apparently it decreases plasma levels of triglycerides by decreasing their synthesis. Also reduces plasma levels of VLDL cholesterol by reducing its release into the circulation and increasing catabolism.
|Brand Name||Generic Name|
|Antara, Lipofen, Tricor,Triglide||fenofibrate|
Cholesterol Absorption Inhibitors
This is a new class of antihyperlipidemic drugs. It works by reducing the absorption of dietary cholesterol, through the intestines.
Bile Acid Sequestrants (also known as Anion-Exchange Resins)
Bile acid sequestrants reduce serum cholesterol levels. They cause no change or sometimes even cause a slight increase in trigylceride concentrations and are therefore not suitable for patients with elevated triglyceride levels. After oral administration, they are not absorbed but bind to bile acids in the intestine and prevent their reabsorption. The bound complex is insoluble and is excreted in the faeces. Decrease in bile acid leads to an increase in hepatic synthesis of bile acids from cholesterol. Depletion of cholesterol from the liver increases LDL receptor activity, which removes LDL cholesterol from the blood.
|Brand Name||Generic Name|
|Colestid, Flavored Colestid||colestipol|
|Questran, Questran Light||cholestyramine|
Nicotinic Acid Group
Niacin (also known as Nicotinic acid) is limited by its side effects especially vasodilatation. In doses of 1.5 to 3 g daily it lowers both cholesterol and triglyceride concentrations by inhibiting synthesis. It also increases HDL cholesterol.
Fish oil preparations are used to lower very high triglyceride levels in the blood.
Combination Drug Therapy
Niacin and ezetimibe are available in combination with statins, as single dose forms.
Ispaghula Husk, a form of soluble fibre, can be used as an adjunct to a lipid lowering diet in patients with mild to moderate hypercholesterolemia. It probably acts by reducing reabsorption of bile acids: plasma triglycerides remain unchanged.
Probucol, has been shown to reduce both LDL and HDL cholesterol levels. It is not available in U.S. but is available in Canada under the following brand names, Bifenabid, Lesterol, Lorelco, Lurselle, Panesclerina, and Superlipid.
If you are diagnosed with high cholesterol, you will probably need to continue lifestyle changes and drug therapy throughout your life. Periodic monitoring of your blood levels is necessary. Reducing high cholesterol levels will slow the progression of atherosclerosis.
Possible complications of high cholesterol include:
When to Contact a Medical Professional
Have your cholesterol checked every 5 years or so, starting between the ages of 20 and 30. If you have high cholesterol or other risk factors for heart disease, make appointments as recommended by your doctor.
To help prevent high cholesterol:
- Maintain a healthy body weight
- Eat a well-balanced, low-fat diet
- Limit cholesterol intake