Type V Hyperlipidaemia

Type V hyperlipidaemia is a severe form of fat disorder in the blood that combines very high levels of triglycerides with the presence of multiple types of lipid particles, putting people at risk for serious complications like pancreatitis and heart disease.

Table of contents

• Identification and Alternative Names
• What Is Type V Hyperlipidaemia?
• Blood Fat Characteristics
• Signs and Symptoms
• How Is It Diagnosed?
• Management and Treatment
• Related Conditions

Identification and Alternative Names

D006954

Hyperlipoproteinemia Type 5, Hyperchylomicronemia Late Onset, Mixed Hyperlipemia, Combined Fat And Carbohydrate-Induced Hyperlipemia, Late-Onset Hyperchylomicronemia, Familial Hyperchylomicronemia With Hyperprebetalipoproteinemia

What Is Type V Hyperlipidaemia?

Type V hyperlipidaemia is a severe type of hyperlipidaemia, which means having abnormally high levels of fats in the blood^[1]. This condition is characterized by the presence of elevated amounts of both chylomicrons (particles that carry fat from food through the bloodstream) and very-low-density lipoproteins (VLDL), along with high triglycerides (the most common type of fat in the body)^[1][5].

Type V hyperlipidaemia is sometimes familial, meaning it can run in families, though it is often associated with other conditions such as diabetes mellitus^[1]. Unlike Type I hyperlipoproteinemia, Type V is not caused by reduced activity of an enzyme called lipoprotein lipase^[1]. The condition is considered an uncommon form of dyslipidaemia, a term used interchangeably with hyperlipidaemia to describe abnormalities in blood cholesterol levels^[2].

Blood Fat Characteristics

People with Type V hyperlipidaemia have a distinct pattern of abnormal blood fats. The condition is marked by increased levels of cholesterol, though the type of cholesterol known as LDL (low-density lipoprotein or “bad” cholesterol) is usually low^[5]. At the same time, there are elevated levels of VLDL, chylomicrons, and triglycerides^[5].

The increase in VLDL is an important feature that helps distinguish Type V from Type I dyslipidaemia, as Type I typically shows normal or only moderately increased VLDL levels^[5]. Chylomicrons, which are normally hard to see in blood plasma after a 12-hour fast, become visible when triglyceride levels rise above 1,000 to 2,000 mg/dL, and symptoms commonly appear when triglycerides reach 2,000 mg/dL or higher^[5].

The elevated triglycerides in Type V hyperlipidaemia can occur due to problems with clearing cholesterol remnants from the blood, reduced activity of the enzyme lipoprotein lipase, or abnormal production of VLDL by the liver and chylomicrons by the intestine^[5].

Signs and Symptoms

Type V hyperlipidaemia often does not cause noticeable symptoms on its own. However, the build-up of fats in the blood can lead to visible signs and serious health complications^[3].

One visible sign is the development of xanthomas, which are small, yellowish bumps or nodules on the skin^[3][5]. These eruptive skin xanthomas typically appear on the buttocks, trunk, and the outer surfaces of the arms and legs. They form due to deposits of fat in the skin and are associated with the presence of chylomicrons in the blood^[5].

The most serious complication of Type V hyperlipidaemia is acute pancreatitis, which is inflammation of the pancreas^[5]. This condition occurs when triglyceride levels exceed 1,000 mg/dL, though symptoms are more common when levels rise above 2,000 mg/dL^[5]. Acute pancreatitis can cause severe abdominal pain and requires immediate medical attention.

People with Type V hyperlipidaemia also have an increased risk of developing atherosclerotic cardiovascular disease (ASCVD), which includes conditions such as heart attack and stroke^[5]. This risk increases further if the person also has diabetes, hypertension, or smokes^[5].

How Is It Diagnosed?

Diagnosis of Type V hyperlipidaemia typically involves blood tests that measure the levels of different types of fats in the blood. A lipid panel is particularly helpful as it provides values for all lipoproteins, as well as cholesterol and triglycerides^[5].

Another diagnostic test measures what is called post-heparin lipolytic activity. In Type V dyslipidaemia, this activity is elevated, which helps distinguish it from Type I, where the activity is absent or decreased^[5]. This test works by administering heparin, a substance that releases the enzyme lipoprotein lipase from blood vessel walls, allowing doctors to measure how active the enzyme is^[5].

Management and Treatment

Managing Type V hyperlipidaemia requires a combination of lifestyle changes and, in many cases, medication. The primary goals are to lower harmful cholesterol and triglyceride levels and to prevent complications such as acute pancreatitis and cardiovascular disease.

Lifestyle Changes

Lifestyle modification is the essential first step in treating Type V hyperlipidaemia^[5]. Important changes include stopping smoking, reducing alcohol consumption, making dietary changes, engaging in regular exercise, and losing weight if necessary^[5].

Diet plays a crucial role in managing this condition. People should reduce their intake of saturated fats found in red meat and full-fat dairy products, and avoid foods with trans fats, which are often found in fried and processed foods^[3]. It’s also important to eat foods rich in omega-3 fatty acids, such as salmon, mackerel, herring, walnuts, and flaxseeds, as these support heart health^[3]. Adding more fruits and vegetables increases fiber intake, which can help reduce cholesterol absorption into the bloodstream^[3].

Regular physical activity is equally important. Engaging in moderate to vigorous exercise for 40 minutes three to four times per week, or a total of 150 minutes weekly, can help reduce total cholesterol levels^[3].

Medications

When lifestyle changes alone are not enough to control cholesterol and triglyceride levels, doctors may prescribe medications. Statins, also known as HMG-CoA reductase inhibitors, are commonly used to reduce cholesterol^[5]. These drugs work by blocking a step in the body’s production of cholesterol.

Fibrates are another class of medication used to treat Type V hyperlipidaemia^[5]. Fibrates work by activating lipoprotein lipase, the enzyme that breaks down triglycerides. Other treatment options include nicotinic acid supplements and fish oil supplements for patients who do not respond well to conventional treatments^[5].

Patients with triglyceride levels above 500 mg/dL should be treated promptly to prevent acute pancreatitis^[5]. Managing Type V hyperlipidaemia is typically a long-term effort that requires ongoing medication and regular monitoring^[3].

Related Conditions

Type V hyperlipidaemia is often associated with several other health conditions. It is frequently seen in people with diabetes mellitus, a condition that affects how the body processes blood sugar^[1]. The condition is also part of a broader group of disorders called hyperlipoproteinemias, which involve abnormally high levels of lipoproteins in the blood^[1].

Because of the high levels of triglycerides and cholesterol, Type V hyperlipidaemia increases the risk of cardiovascular disease, including heart attack, stroke, and atherosclerosis (the build-up of plaque in arteries)^[3][5]. The condition can also lead to acute pancreatitis, a painful and potentially dangerous inflammation of the pancreas^[5].