Familial combined hyperlipidemia

Alternative names
Multiple lipoprotein-type hyperlipidemia

Definition
This is an inherited disorder of high serum cholesterol and/or high blood triglycerides People with this condition have an increased risk of cardiovascular disease.

Causes, incidence, and risk factors

This disease is genetic and inherited, although the specific defective genes have not been identified. The person’s cholesterol or triglyceride levels become elevated during the teenage years and continue throughout life. The types of elevated lipoproteins may vary between affected family members.

Cholesterol deposits in the skin, called xanthomas, which are seen in other disorders of elevated lipoproteins are rarely seen in this disorder. This disorder predisposes the person to greater risk of early coronary artery disease and therefore, heart attacks. People with the condition have a higher rate of obesity and glucose intolerance.

The condition is worsened by diabetes, alcoholism, and hypothyroidism. Risk factors are a family history of High cholesterol and early coronary artery disease. This is the most common disorder of increased blood fats that causes early heart attacks. The rare person who gets 2 defective genes is at much higher risk for early heart attack due to very high blood fat (cholesterol or triglyceride) levels.

Symptoms

• The person may be obese
  
• Chest pain (angina)
  
• Family history of early heart attack or increased blood fats

Note: There may be no symptoms.

Signs and tests

• elevated serum LDL or VLDL
  
• elevated total cholesterol
  
• decreased or normal serum HDL cholesterol
  
• elevated triglycerides
  
• elevated apolipoprotein B100 test
  
• pedigree analysis may show parent or child with high blood fat

Treatment

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

The first step is to change what you eat. This is tried for several months before drug therapy is added. Diet changes include reducing total fat intake to less than 30% of the total calories consumed. Saturated fat intake is reduced by decreasing the amounts of beef, chicken, pork, and lamb; substituting low-fat dairy products for full-fat ones; and eliminating coconut and palm oil. Cholesterol intake is reduced by eliminating egg yolks and organ meats.

Further reductions in dietary fat may be recommended after the initial trial period. Dietary counseling is often recommended to help people make these adjustments to their eating habits. Weight loss and regular exercise may also aid in lowering cholesterol levels.

Drug therapy may be initiated if diet, exercise, and weight loss efforts have not reduced the cholesterol levels after an adequate trial period. Various cholesterol reducing agents are available including:

• bile acid-sequestering resins (cholestyramine and colestipol)
  
• Nicotinic Acid
  
• lovastatin and other ‘statin’ drugs
  
• gemfibrozil
  
• probucol

Expectations (prognosis)
The probable outcome is related to early diagnosis and treatment and compliance with therapy. Untreated people are at risk for shortened life span due to heart attack and stroke. The person with 2 defective genes has such high lipids that they are unlikely to be able to reduce their risk of coronary artery disease to normal. Therefore, they are at increased risk of heart attack despite medical therapy.

Complications
A complication is early atherosclerotic heart disease or myocardial tissue death due to lack of blood (infarction). The fatty deposits can affect the blood vessels to the brain causing an increase risk for stroke.

Calling your health care provider
Call your health care provider if you experience warning symptoms of heart attack or your screening total cholesterol or triglycerides was found to be high.

Prevention

• A low-cholesterol, low-saturated fat diet in high-risk individuals may help to control LDL levels.
  
• Screening of family members of people with familial combined hyperlipidemia should be undertaken to facilitate early treatment. 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.
  
• Genetic counseling is recommended for family members.

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