Approximately 1 in 100 people have mixed hyperlipidemia. This condition increases your risk for cardiovascular disease (CVD) morbidity and mortality. In addition, people who have mixed hyperlipidemia also have a higher frequency of other metabolic disorders such as type 2 diabetes (T2D), nonalcoholic fatty liver disease (NAFLD), and metabolic syndrome.
Read on to learn more about mixed hyperlipidemia. This article will discuss possible causes, treatment options, symptoms, and complications associated with the disorder.
Mixed hyperlipidemia is a condition characterized by abnormal lipid metabolism, which can result in the following:
- elevated triglycerides (TGs)
- elevated low-density lipoprotein (LDL)
- elevated very low-density lipoprotein (VLDL)
- reduced high-density lipoprotein (HDL)
HDL helps to remove excess lipids from the circulation and arteries to be excreted by the liver. Having low levels of HDL is a possible risk factor for CVD. Conversely, having too much TGs and LDL in the blood can promote plaque buildup in the arteries and increase your risk for CVD. High VLDL can also contribute to plaque deposits in the arteries.
Mixed hyperlipidemia can also manifest as a normal blood lipid profile in combination with abnormally elevated levels of apolipoprotein B.
Mixed hyperlipidemia is the same as familial combined hyperlipidemia. People often use the terms interchangeably.
Researchers believe that mixed hyperlipidemia primarily occurs as a result of genetic inheritance. However, research is still ongoing to determine which specific genes or other causal factors play a role. It appears to be a complex, multifaceted disorder related to genetic variants, environmental factors, and lifestyle.
Researchers have identified more than 30 different genetic variants associated with mixed hyperlipidemia.
The three primary known genetic mutations in mixed hyperlipidemia cause defects in the following receptors:
- LDL
- ApoB
- PCSK9
Each of these mutations leads to the reduction in uptake of LDL cholesterol, therefore causing high LDL cholesterol in the circulation.
You may not experience any symptoms in the early years of mixed hyperlipidemia.
As the condition progresses, plaque buildup and narrowing of the arteries can disrupt blood flow. The symptoms are usually associated with atherosclerosis, and can include:
- chest pain
- sudden stroke-like symptoms
- difficulty breathing
- discomfort in one or both shoulders
- cramping in one or both calves
People who have mixed hyperlipidemia may develop high cholesterol or high triglyceride levels as early as adolescence. Doctors may also diagnose the condition when people are in their 20s or 30s. The levels are likely to remain high throughout life.
Doctors may use a combination of medications and lifestyle modifications to treat mixed hyperlipidemia.
Medications
Your doctor may prescribe medications to lower your cholesterol levels, such as:
- statins, which reduce cholesterol synthesis in the liver
- fibrates, such as gemfibrozil (Lopid) and and fenofibrate (Tricor)
- bile acid sequestrants, such as cholestyramine (Questran) and colesevelam (Welchol)
- niacin or nicotinic acid
- PCSK9 inhibitors, such as alirocumab (Praluent) and evolocumab (Repatha)
- ezetimibe
Learn more about medications doctors prescribe for lowering cholesterol.
Lifestyle changes
Lifestyle modifications can help lower your cholesterol and decrease your risk for cardiovascular disease. These include:
- eating a heart-healthy diet, such as the Mediterranean or DASH diet
- reducing your saturated fat intake
- exercising regularly
- consuming more fiber
- eliminating or reducing your intake of ultra-processed foods
- stopping smoking if you currently smoke
- reducing your intake of alcohol
- maintaining a healthy body weight
- consuming omega-3 fatty acids, which can reduce your triglycerides
The American Heart Association recommends all adults over the age of 20 years have their blood lipids tested every 4–6 years. People who have other risk factors may need to undergo more frequent testing.
If you are experiencing any heart attack or stroke-like symptoms, seek immediate medical attention.
The symptoms of a stroke can include:
- inability to speak
- issues with coordination or movement
- paralysis on the face, leg, or arm, usually on one side of the body
- vision issues in one eye
- confusion
- a severe migraine with no known cause
Learn more about the signs and symptoms of a stroke.
The symptoms of a heart attack can include:
- discomfort in one or both shoulders
- chest pain
- shortness of breath
- irregular heartbeat
- pain, numbness, and swelling in the feet and ankles
Learn more about heart attacks.
Doctors diagnose mixed hyperlipidemia mainly through a routine fasting blood test that measures your lipid panel, a physical exam, and a thorough assessment of family medical history.
The lipid panel will evaluate the following:
- triglycerides
- LDL-C
- HDL-C
- total cholesterol
- apolipoprotein B100
You may need to fast for approximately 12 hours before the blood test. Your doctor will be able to advise on this beforehand.
Cholesterol measurements are in milligrams per deciliter (mg/dl). The table below lists the target levels.
| Test | Target levels |
| Apolipoprotein B100 | less than 100 mg/dl |
| LDL | less than 100 mg/dl |
| HDL | 60 mg/dl or above |
| Total cholesterol | less than 200 mg/dl |
| Triglycerides | less than 150 mg/dl |
Your doctor may also use a carotid ultrasound, which is a diagnostic imaging technique that evaluates the arteries for narrowing and plaque buildup.
Currently, no definitive genetic test can confirm a diagnosis of mixed hyperlipidemia. However, the Centers for Disease Control and Prevention (CDC) suggest that screening for mutations of the following genes may help determine if a person probably has an inherited lipid disorder:
- PCSK9
- APOB
- LDLR
A family history of mixed hyperlipidemia increases your risk of developing the condition. If one parent has mixed hyperlipidemia, you have a 50% chance of acquiring the condition.
If both parents have mixed hyperlipidemia, you may acquire what doctors call a “double dose,” which can put you at higher risk for medical complications earlier in life.
Certain factors may impact your cholesterol. These include:
- kidney disease
- liver disease
- hypothyroidism
- insulin resistance
- obesity
- high blood pressure
- alcoholism
- metabolic syndrome
- type 2 diabetes
Complications from mixed hyperlipidemia manifest when the abnormally high lipids in your blood begin to deposit in your arteries and disrupt blood flow. This can cause complications such as:
- heart attack
- coronary heart disease
- stroke
- carotid artery disease
- peripheral artery disease
- microvascular disease
Mixed hyperlipidemia is an inherited disorder, so you cannot prevent it. However, early diagnosis and following an effective treatment plan can help reduce your risk of developing severe complications. Some preventive measures your doctor may recommend are:
- eating a nutritious, heart-healthy diet
- maintaining a healthy body weight
- not smoking
- reducing alcohol consumption
- exercising regularly
- managing stress levels
- getting proper sleep
If your lipid levels are still not within a target range with lifestyle modifications, your doctor may prescribe lipid-lowering medications.
Mixed hyperlipidemia, also known as familial combined hyperlipidemia, is a condition that causes high levels of lipids in the blood, such as triglycerides and LDL. This increases your risk for heart attack and stroke. People who have mixed hyperlipidemia also have a higher risk of developing other conditions such as type 2 diabetes, metabolic syndrome, and NAFLD.
Researchers do not yet fully understand the exact cause of mixed hyperlipidemia. It is possible that it occurs due to a complex array of genetic variants combined with environmental factors. The American Heart Association and CDC recommend getting your blood lipids tested every 4–6 years and more frequently if you have risk factors, such as a family history of high cholesterol.
Contact your doctor to schedule an examination if you have concerns about your cholesterol, have a family history of high cholesterol or CVD, or are due for a routine test.
