Primary Hypercholesterolaemia
Primary hypercholesterolaemia is a condition where your blood contains too much “bad” cholesterol, specifically low-density lipoprotein (LDL). While it usually causes no symptoms, it silently increases your risk of heart attacks and strokes by allowing fat to build up in your arteries.
Table of contents
- What is primary hypercholesterolaemia?
- How common is it?
- Signs and symptoms
- What causes high cholesterol?
- Who is at higher risk?
- How is it diagnosed?
- What problems can it cause?
- Treatment options
- How to prevent high cholesterol
What is primary hypercholesterolaemia?
Primary hypercholesterolaemia is a lipid disorder (a problem with fats in your blood) in which your low-density lipoprotein (LDL), known as “bad cholesterol,” is too high[1]. This condition is also referred to as dyslipidaemia, which is a broader term that includes elevated triglycerides (another type of fat in blood), low levels of HDL cholesterol (the “good” cholesterol), and other abnormalities in blood fats[4].
hypercholesterolaemia, high cholesterol, dyslipidaemia
Cholesterol itself is a waxy substance found in your blood that your body needs to build healthy cells[3]. Your liver makes all the cholesterol your body needs[18]. However, when you have too much LDL cholesterol, fat collects in your arteries in a process called atherosclerosis. This buildup, known as plaque, makes your arteries narrow and stiff over time, which puts you at higher risk of heart attack and stroke[1].
What your doctor considers hypercholesterolaemia depends on your other risk factors for heart and blood vessel disease. Generally, LDL cholesterol levels are classified as high when they are 190 mg/dL or higher without other risk factors, higher than 160 mg/dL with one major risk factor, or above 130 mg/dL with two risk factors[2][1].
How common is it?
Hypercholesterolaemia is very common. About 1 out of every 20 people has hypercholesterolaemia, and nearly one-third of American adults have high LDL cholesterol[1]. About 34 million adults in the United States have high blood cholesterol[7].
Signs and symptoms
Most people with hypercholesterolaemia have no symptoms at all. High cholesterol is usually symptomatically quiet until significant atherosclerosis has developed[4]. The only way to find out if you have it is through a blood test[3].
However, if you have severe hypercholesterolaemia, you may notice some physical signs. These include cholesterol deposits on your eyelid skin, which appear as yellowish patches called xanthelasma. You might also have cholesterol deposits on connective tissue called xanthoma, often appearing as bumps or lumps around your knees, knuckles, or elbows. Additionally, you may have a swollen or painful Achilles tendon (the tendon at the back of your lower leg), or a whitish gray color in the shape of a half-moon on the outside of your cornea, called a corneal arcus[1][6].
What causes high cholesterol?
Primary hypercholesterolaemia can have several causes. The most important include:
Genetics: Some people inherit genes that cause high cholesterol. This is called pure or familial hypercholesterolaemia. Familial hypercholesterolaemia is an inherited condition that affects about 1 in 311 people and increases the chance of having coronary artery disease at a younger age[6][1].
Diet: Eating a lot of saturated fats and trans fats can cause your liver to produce more cholesterol or reduce its ability to remove cholesterol from your blood[1][8]. Saturated fats come from animal products such as cheese, fatty meats, and dairy desserts, as well as tropical oils like palm oil[18].
Lack of exercise: Physical inactivity can lead to high cholesterol. Being active raises the level of “good” cholesterol and reduces the level of “bad” cholesterol[8][1].
Tobacco use: Smoking can lead to high cholesterol levels. It causes tar to build up in your arteries, making it easier for cholesterol to stick to your artery walls[8][1].
Medical conditions: Several health conditions can contribute to high cholesterol, including diabetes, hypothyroidism (underactive thyroid), obstructive liver disease, cholestatic liver disease, nephrotic syndrome, and chronic kidney failure[1][4].
Certain medications: Some medicines can raise cholesterol levels, including amiodarone, rosiglitazone, cyclosporine, and hydrochlorothiazide[1].
Who is at higher risk?
Several factors increase your likelihood of having high LDL cholesterol:
Age: You are more likely to have high cholesterol if you are a man aged 45 years or older, or a woman aged 55 years or older[2]. Getting older is a risk factor because it reflects the impact of all risk factors over your lifespan[10]. People over 40 are at higher risk[1].
Family history: Having a positive family history of premature atherosclerotic cardiovascular disease (heart disease in a male family member younger than 55 years or in a female family member younger than 65 years) increases your risk[2][1].
Ethnicity: People who are Asian Indian, Filipino, or Vietnamese are more likely to have high LDL cholesterol[1].
Sex: Women, especially those who are post-menopausal, are at higher risk[1][8].
Other health conditions: Having high blood pressure, diabetes, or low levels of HDL (“good cholesterol”) increases your risk[1][2].
Lifestyle factors: A sedentary lifestyle, excess body weight (especially around your middle), and smoking all raise your risk of high cholesterol[4][8].
How is it diagnosed?
Your healthcare provider will diagnose hypercholesterolaemia through several steps:
Medical and family history: Your provider will ask about your medical history and your family’s health history, particularly whether family members have had high cholesterol levels or heart disease, especially during childhood[1][13].
Physical examination: During the exam, your healthcare team will check for cholesterol deposits that may appear on the skin around your hands, knees, elbows, and eyes. They will also look for thickened tendons in the heel and hand, and check whether a gray or white ring has developed around the iris of your eye[13].
Blood tests: Your provider will order a lipid panel blood test, which measures total cholesterol, LDL cholesterol (estimated or direct), HDL cholesterol, and triglycerides[4][1]. You usually need to fast before this test. The American Heart Association recommends that children get screened for high cholesterol once between ages 9 and 11, with the next screening between ages 17 and 21, and then every five years after that for adults[3].
Genetic testing: Once your provider rules out other causes of your hypercholesterolaemia, they can perform genetic testing. If you have familial hypercholesterolaemia, your provider may suggest genetic testing for your family members as well[1][6].
What problems can it cause?
Hypercholesterolaemia is an important risk factor for atherosclerotic cardiovascular disease, which includes cerebrovascular disease, coronary heart disease, and peripheral arterial disease[4]. Atherosclerosis is the main cause of cardiovascular disease, which causes more deaths than anything else in the world[1].
Specific complications of hypercholesterolaemia and atherosclerosis include:
- Myocardial infarction (heart attack)[4]
- Stroke[1][4]
- Coronary artery disease[1]
- Peripheral artery disease[1][4]
- Ischaemic cardiomyopathy[4]
- Sudden cardiac death[4]
- Erectile dysfunction[4]
- Claudication (leg pain when walking)[4]
- Acute limb ischaemia[4]
For people with familial hypercholesterolaemia, if left untreated, heart attacks happen in 30% of women by age 60 and 50% of men by age 50[6]. However, finding and treating familial hypercholesterolaemia early can reduce the risk of coronary artery disease by about 80%[6].
Treatment options
Hypercholesterolaemia treatment focuses on bringing down your LDL level to prevent heart disease. Treatment combines lifestyle modifications with medications when necessary[4][1].
Lifestyle changes
Diet modifications: Eating a heart-healthy diet is essential. You should reduce saturated fats, which are found primarily in red meat and full-fat dairy products, as they raise your total cholesterol and LDL cholesterol. You should also eliminate trans fats, sometimes listed on food labels as “partially hydrogenated vegetable oil,” as they raise overall cholesterol levels[16]. Instead, choose foods that are low in saturated fat, trans fat, sodium, and added sugars, including lean meats, seafood, fat-free or low-fat dairy, whole grains, fruits, and vegetables[18].
Eat foods naturally high in fiber, such as oatmeal, kidney beans, apples, pears, and barley. These foods may help prevent and manage high levels of LDL cholesterol and triglycerides. Foods rich in omega-3 fatty acids, including salmon, mackerel, herring, walnuts, and flaxseeds, have heart-healthy benefits[16][18].
Physical activity: Starting a regular exercise program can help raise HDL (“good” cholesterol), lower LDL and triglycerides, and improve blood flow. Adults should aim for 2 hours and 30 minutes of moderate-intensity exercise, such as brisk walking or bicycling, every week. Children and adolescents should get 1 hour of physical activity every day[18].
Weight management: Maintaining a healthy weight is important because overweight and obesity raise levels of LDL cholesterol. Excess body fat affects how your body uses cholesterol and slows down your body’s ability to remove LDL cholesterol from your blood[18].
Quit smoking: If you smoke, quitting will lower your risk for heart disease. Smoking damages your blood vessels, speeds up the hardening of arteries, and greatly increases your risk for heart disease[18].
Limit alcohol: Too much alcohol can raise cholesterol levels and triglycerides. Men should have no more than two drinks per day, and women should have no more than one[18].
Medications
For people with very high cholesterol, especially familial hypercholesterolaemia, diet and lifestyle changes are often not sufficient to achieve the desired lowering of LDL, and lipid-lowering medications are usually required[7].
Statins are the most widely used cholesterol-lowering drugs and have the most convincing data for preventing cardiovascular disease. They reduce the production of cholesterol in your liver[2][15]. For patients with known cardiovascular disease, statin therapy is recommended, and high-dose statins should be initiated in patients with acute coronary syndrome[2].
Other medications that may be used include ezetimibe, bempedoic acid, and PCSK9 inhibitors. These drugs work through different mechanisms to lower LDL cholesterol[10][15].
If necessary, other treatments such as LDL apheresis (a procedure to remove LDL from the blood) or even surgery may be performed for particularly severe subtypes of familial hypercholesterolaemia[7].
How to prevent high cholesterol
By living a healthy lifestyle, you can help keep your cholesterol in a healthy range and prevent high cholesterol[18].
Eat a heart-healthy diet: Your body makes all the cholesterol it needs, so you do not need to obtain cholesterol through foods. Limit foods high in saturated fat, and choose foods that are low in saturated fat, trans fat, sodium, and added sugars[18].
Stay physically active: Make physical activity a part of each day. Take the stairs instead of the elevator, park a little farther away, walk to the store, or do jumping jacks during commercials[18].
Maintain a healthy weight: Work with your doctor on a food and fitness plan to help you reach or maintain a healthy weight[18].
Don’t smoke: If you don’t smoke, don’t start. If you do smoke, talk with your doctor about ways to help you quit[18].
Limit alcohol: Avoid drinking too much alcohol, as it can raise cholesterol and triglyceride levels[18].
Work with your healthcare team: You and your healthcare team can work together to prevent high cholesterol. Get regular cholesterol screenings and discuss your other medical conditions and any medicines you are taking[18].
Following these prevention steps is especially important if you have a family history of high cholesterol or heart disease. Making healthy lifestyle changes for your family can benefit your children who may be at risk and promote healthy habits that they will continue as adults[6].
