What Is Non-HDL Cholesterol?

What is non-HDL cholesterol?

Cholesterol is a waxy substance that is both made in the body and present in food.

It is made up of different classes of lipoproteins: high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and chylomicrons.

HDL cholesterol is sometimes called the ‘good’ cholesterol; it is the type of cholesterol you want in your body. It is good because it removes LDL cholesterol¹ (‘bad’ cholesterol) from the bloodstream.

It does this by absorbing LDL cholesterol and transporting it to the liver, where it is then removed from the body. Removing LDL from the blood also reduces the risk of heart disease and stroke.

Non-HDL cholesterol is simply all types of cholesterol that are not HDL. You might like to consider it a measure of the ‘bad’ cholesterol in your body. 

Dyslipidemia is a condition in which there is an imbalance of lipids in the body, such as high levels of non-HDL cholesterol or low levels of HDL cholesterol.

Types of non-HDL cholesterol

There are four lipoprotein classes that make up non-HDL cholesterol. Each has a functional role in the body, meaning it needs them. However, issues can arise when levels of these lipoproteins rise too high. 

Low-density lipoprotein

Low-density lipoprotein² (LDL) circulates in the body via the blood to where the body needs it for cell repair. LDL can also deposit on the inside of the walls of arteries. This can cause problems when the blood contains high levels of LDL, as these deposits can build up, forming what is known as ‘plaque’ within the arteries. 

The buildup of plaque in the artery walls means there is increasingly less space for the blood to pass through the artery, essentially narrowing the artery. This narrowing of arteries raises blood pressure and blocks blood from reaching your vital organs. This increases the risk of chest pain (angina), strokes, and heart attacks. 

Very low-density lipoprotein

Very low-density lipoprotein (VLDL) transports triglycerides obtained from food to cells in the body. It is produced in the liver.

VLDL is converted into IDL when muscle and fat tissues remove triglycerides from VLDL molecules. IDL is then converted into LDL in the bloodstream. Therefore, VLDL contributes to the amount of ‘bad’ cholesterol in the blood. 

Intermediate-density lipoprotein

Intermediate-density lipoprotein (IDL) is metabolized from VLDL. Its role is to aid fats and cholesterol in moving through the bloodstream. 

Chylomicrons

Chylomicrons transport triglycerides and cholesterol that are obtained from the diet into the tissues and the liver. Chylomicrons are synthesized in the liver. 

How important is the ratio of non-HDL and HDL cholesterol?

The ratio of HDL to non-HDL cholesterol is very important for your health. The role of HDL in the body is to remove LDL from the body, reducing the levels of ‘bad’ cholesterol in the bloodstream. A healthy adult should have high HDL and low non-HDL cholesterol levels. 

The presence of high levels of non-HDL and low levels of HDL is a risk factor for heart disease. This is because having high levels of LDL in the blood increases the LDL plaques that can form, while a lower concentration of HDL reduces the body’s ability to transport the LDL away. 

Clinical trials³ have shown that lowering LDL cholesterol levels significantly reduces cardiovascular disease. It is important, though, to remember that while LDL is known as the ‘bad’ cholesterol, other non-HDL cholesterol are also important in indicating dyslipidemia.

Research⁴ has shown that non-HDL cholesterol levels are a better indicator of cardiovascular disease than simply testing LDL cholesterol levels alone.

Risk factors for high non-HDL cholesterol

Although anyone can develop high non-HDL cholesterol due to a high-fat diet, some risk factors raise the likelihood of this developing.

Obesity

In people with obesity, the LDL cholesterol particles are often dense and small. These small and dense LDL particles don’t bind as well and have less affinity for the LDL receptors than large LDL particles.

LDL receptors bind the LDL and remove it from the blood. This means that the small LDL particles remain in the bloodstream and are more likely to deposit in the arterial wall, forming plaque. 

Sedentary lifestyle

Research⁵ has shown that exercise can decrease the levels of LDL in the bloodstream. Additionally, excess body fat can slow the removal of LDL from the body. Maintaining a sedentary lifestyle increases the risk of high levels of ‘bad’ cholesterol.

Hypothyroidism

Hypothyroidism is a condition in which the thyroid does not synthesize and release enough thyroid hormones into the blood. Thyroid hormones are important for regulating cholesterol levels as these hormones stimulate the activity of the LDL receptors. These receptors remove LDL from the bloodstream. 

When the thyroid is underactive, there are fewer thyroid hormones in the bloodstream, leading to less activity of the LDL receptors, causing an increase of LDL circulating in the blood. This increased amount of LDL in the bloodstream may lead to the formation of plaque in the arteries.

Chronic kidney disease

With chronic kidney disease, the function of the kidney is impaired. The role of the kidney is to remove toxins and waste from the body. When the function of the kidney is impaired, clearance of VLDL from the bloodstream is reduced. This raises the level of non-HDL cholesterol in the body.

Type 2 diabetes

When you have type 2 diabetes, the body either is resistant to or does not make enough insulin. Insulin stimulates the expression of the LDL receptor. This means that insulin can activate the process of LDL receptors appearing.

With less insulin being produced in the body, there is less stimulation of LDL receptor expression, resulting in fewer LDL receptors taking up LDL from the bloodstream. This causes an increase in LDL circulating in the blood.

Additionally, in people with type 2 diabetes, the LDL particles tend to be small and dense, similar to people with obesity. These small and dense LDL particles are less likely to be taken up by the LDL receptors than larger LDL particles that are more common in healthy people. This causes an increase in LDL in the bloodstream, raising non-HDL cholesterol levels.

Infection and inflammation

Similar to what happens in obesity and type 2 diabetes, infection and inflammation can cause LDL particles to be small and dense.

This causes the LDL to be retained in the bloodstream as small, dense particles are less likely to be taken up by the LDL receptor than larger particles. This raises the overall non-HDL cholesterol levels in the blood.

Symptoms of high non-HDL cholesterol

Generally, high non-HDL cholesterol does not cause any symptoms. However, some symptoms may occur in some cases, usually the more severe ones.

Hypertension

Hypertension is a condition in which the blood pressure is too high. This can happen as a result of high non-HDL cholesterol as the formation of cholesterol plaques in the arteries narrows the arteries, raising blood pressure.

Although high blood pressure is often symptomless, you may have hypertension if you are experiencing the following symptoms:

• Dizziness

• Facial flushing

• Blurred vision

• Headache

These symptoms are not always linked to high blood pressure; however, if you are experiencing them, you should visit your doctor.

Xanthomas

Xanthomas⁶ are yellowish nodules or plaques filled with lipids (including cholesterol). Sometimes, in cases of severe hypercholesterolemia — high cholesterol — xanthomas can develop on the skin. Common places for these to develop are on the Achilles tendon or the eyelids.

Diagnosis of high non-HDL cholesterol

To be diagnosed with high non-HDL cholesterol, you need to visit a doctor.

The doctor will do a non-HDL cholesterol blood test and will be able to provide support and guidance if you do have high non-HDL cholesterol.

Non-HDL cholesterol test

A doctor will do a lipid panel test⁷ to diagnose high non-HDL cholesterol, which is obtained by a simple blood draw. The blood will be tested for total cholesterol, HDL, LDL, and triglyceride levels. To determine the level of non-HDL cholesterol, the HDL count will be subtracted from the total cholesterol measurement. 

Generally, for this test, you will not need to have fasted in preparation. However, in some cases, a doctor may recommend you fast for 8 to 12 hours before a blood test. This can be if you have a condition that affects the levels of triglycerides and lipids in your blood.

This includes: 

• Family history of high cholesterol

• Early onset heart disease

• Hypertriglyceridemia

• Pancreatitis

• Type 2 diabetes

• Obesity

• Medications such as thiazides or beta-blockers

What are optimal cholesterol levels?

The following table demonstrates the optimal cholesterol levels. Cholesterol is measured in milligrams per deciliter (mg/dL).

How to lower your non-HDL cholesterol levels

There are many lifestyle changes that you can make to help lower your levels of non-HDL cholesterol. These tips are also beneficial for those who do not have high cholesterol or are waiting on confirmation from test results, as it is all about maintaining a healthy lifestyle.

Dietary changes

Reassessing the food choices you make can have a significant impact on the levels of non-HDL cholesterol in your body. 

High fiber foods

Consuming foods high in fiber can reduce the amount of non-HDL circulating in the blood. Research⁸ has shown that consuming oats, a source of beta-glucan (a type of fiber), can significantly lower non-HDL cholesterol. Other foods high in fiber include: 

• Beans (black, pinto, kidney) 

• Berries

• Avocado 

Unsaturated fats

Saturated fats are often consumed through animal products (fatty meats and full-fat dairy) and palm oil. Foods high in saturated fat may be high in cholesterol. Instead of consuming these products, opt for foods high in unsaturated fats such as: 

• Avocado

• Vegetable oils

• Nuts

Foods with high levels of unsaturated fats may prevent and help manage high amounts of LDL and triglycerides in the blood while also increasing the amount of HDL. 

Sugary drinks

The consumption of sugary beverages has been associated with increased LDL cholesterol levels in the blood. Opting for drinks without added sugar or water will help keep your LDL cholesterol levels down.

Maintain a healthy weight

Maintaining a healthy weight will improve your levels of non-HDL cholesterol as excess body fat serves to slow the removal of LDL from the bloodstream. You can get an estimate of whether your weight is healthy or not by measuring your BMI. 

However, a BMI⁹ is not entirely accurate; there are a number of factors that are important in determining a healthy weight that the BMI does not include.

If you have high cholesterol or are concerned about your weight, it is best to visit your doctor to discuss what a healthy weight for you would be. 

Quit smoking

Smoking damages your blood vessels and increases the hardening of your arteries. This alone increases your risk of cardiovascular disease. If you have high non-HDL cholesterol, your risk of cardiovascular disease is additionally increased.

If you have high non-HDL cholesterol, seek help from your doctor to quit smoking. This will reduce your risk of developing cardiovascular disease as a complication of high non-HDL cholesterol.

Medication

If these lifestyle changes do not lower your non-HDL levels enough or you have very high non-LDL cholesterol in your blood, your doctor may prescribe some medications called statins.

Moderate-intensity statin therapy may reduce LDL cholesterol in the blood by 30–50%. If you and your doctor decide moderate-intensity statin therapy is right for you, you may be prescribed one of the following medications. 

If moderate-intensity statin therapy is not sufficient to reduce your non-HDL cholesterol, your doctor may suggest high-intensity statin therapy. This involves taking larger daily doses of the medication. 

When you should see a doctor

If you are experiencing the symptoms of hypertension or developing xanthomas, you should see a doctor as this may indicate an imbalance in your cholesterol levels.

As high non-HDL cholesterol is mainly symptomless, it is important to visit your doctor for regular cholesterol checks. Healthy adults should get a cholesterol test every four to six years.

Children should have a cholesterol test at least once between the age of nine to 11 years and again between the age of 17–21.

Some conditions raise your risk of developing high non-HDL cholesterol levels, increasing the risk of cardiovascular disease. If you experience any of the following conditions, you will need cholesterol tests more regularly than the general guidelines stated above.

• Heart disease

• Family history of high cholesterol

• Diabetes

• Hypertension

• Obesity

The lowdown

Non-HDL cholesterol collectively describes all of the ‘bad’ cholesterol types. HDL cholesterol is the ‘good’ cholesterol that helps to remove the ‘bad’ cholesterol from the body. Higher HDL levels help protect the heart and lower the risk of plaque buildup in the blood vessels.

There are a number of conditions that increase your risk of developing high non-HDL cholesterol, including obesity, type 2 diabetes, a sedentary lifestyle, and hypothyroidism. High levels of non-HDL cholesterol increase the risk of cardiovascular diseases and heart attacks.

You can reduce your levels of non-HDL cholesterol by maintaining a healthy lifestyle and a healthy weight. Your doctor may also prescribe medication to help lower your cholesterol levels. Speak with your doctor to find the best option for you.