Familial combined hyperlipidemia

Causes

Familial combined hyperlipidemia is the most common genetic disorder of increased blood fats that causes early heart attacks. However, researchers have not yet identified the specific genes responsible.

Diabetes, alcoholism, and hypothyroidism make the condition worse. Risk factors include a family history of high cholesterol and early coronary artery disease.

Symptoms

Chest pain (angina) may occur. However, there may not be any physical symptoms.

Persons with this condition develop high cholesterol or triglyceride levels during the teenage years. The levels remain high throughout life. They have an increased risk of early coronary artery disease and heart attacks. Those with familial combined hyperlipidemia have a higher rate of obesity and glucose intolerance.

Exams and Tests

Blood tests will be done to check your levels of cholesterol and triglycerides. Specific tests include:

• LDL test (increased)
• HDL test (decreased)
• Triglycerides test (increased)
• Apolipoprotein B100 test (increased)

Genetic testing is available for one type of familial combined hyperlipidemia.

Treatment

The goal of treatment is to reduce the risk of atherosclerotic heart disease.

LIFESTYLE CHANGES

The first step is to change what you eat. Most of the time, this is tried for several months before your doctor recommends medicines, too. Diet changes include lowering the amount of fat in your diet so it is  less than 30% of your total calories.

Here are some ways to eat less saturated fat:

• Eat less beef, chicken, pork, and lamb
• Substitute low-fat dairy products for full-fat ones
• Eliminate palm oil

You can reduce your the amount of cholesterol you eat by eliminating egg yolks and organ meats.

Counseling is often recommended to help people make changes to their eating habits. Weight loss and regular exercise may also help lower your cholesterol levels.

See also: Heart disease and diet

MEDICATIONS

 If lifestyle changes do not change your cholesterol levels, or you are at very high risk of developing atherosclerotic heart disease, your doctor may recommend medication. There are several types of drugs available to help lower blood cholesterol levels, and they work in different ways. Some are better at lowering LDL cholesterol, some are good at lowering triglycerides, while others help raise HDL cholesterol.

The most commonly used and effective drugs for treating high LDL cholesterol are called statins. The include lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol), atorvastatin (Lipitor), rosuvastatin (Crestor), and pitivastatin (Livalo). 

Other cholesterol-lowering medicines include:

• Bile acid-sequestering resins
• Ezetimibe
• Fibrates (such as gemfibrozil and fenofibrate)
• Nicotinic acid

Outlook (Prognosis)

How well you do depends on how early the condition is diagnosed, when treatment is received, and whether you follow your treatment instructions. Without treatment, heart attack or stroke may cause early death.

Even with medicine, some people may continue to have high lipid levels that increase their risk of heart attack.

Possible Complications

• Early atherosclerotic heart disease
• Heart attack
• Stroke

When to Contact a Medical Professional

Seek immediate medical care if you have chest pain or other warning signs of a heart attack.

Call for an appointment with your health care provider if you have a personal or family history of high cholesterol levels.

Prevention

A low-cholesterol, low-saturated fat diet in high-risk individuals may help to control LDL levels.

If someone in your family has this condition, you may want to consider genetic screening for yourself or your children. Sometimes younger children may have mild hyperlipidemia.

It is important to control other risk factors for early heart attacks, such as smoking, if you have this disease.

Alternative Names

Multiple lipoprotein-type hyperlipidemia

References

Genest J, Libby P. Lipoprotein disorders and cardiovascular disease. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA:Saunders Elsevier; 2011:chap 47.

Semenkovich, CF. Disorders of lipid metabolism. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 213.

Update Date: 6/4/2012

Updated by: David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc. David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.