High Cholesterol

Cholesterol is a fat made by your liver. There are two types of cholesterol: HDL and LDL. HDL (high-density lipoprotein) cholesterol is often referred to as ‘good cholesterol’, because it helps to reduce your levels of LDL (low-density lipoprotein) cholesterol, which is ‘bad cholesterol. If you have high cholesterol, you have a high level of LDL cholesterol, which is involved in blocking up your arteries. This causes your arteries to narrow and thicken, increasing your blood pressure and putting you at risk of stroke, heart attack and heart disease.

High cholesterol is often treated by statins and lifestyle changes such as quitting smoking. The goal is to reach an LDL value of less than 100mg/dL which is especially important in patients who have other cardiac risk factors that could raise the risk of coronary artery disease (CAD). These risk factors are diabetes, cigarette smoking, hypertension, low HDL, and a family history of CAD.

High cholesterol is usually caused by a genetic defect that interferes with the ability of HDL to clear away the LDL, allowing it to build up inside the arteries. However, consuming a diet of high-fat foods and food containing high levels of cholesterol is an additional factor, that often contributes -though rarely causes - high cholesterol. Foods that contain high levels of cholesterol include: eggs, cheese, shellfish, liver, red meat etc.

Most people with high cholesterol do not have any signs or symptoms unless there is a genetic cause. This can cause cholesterol to build up the skin, creating yellowish patches, known as xanthomas. Other symptoms of high cholesterol include:

• Pain with walking from decreased blood flow to the legs from clogged arteries
• Transient ischemic attack (TIAs) temporary reduction in blood flow to the brain
• Chest pain
• Difficulty breathing

High cholesterol is diagnosed by a simple blood test that measures the levels of both LDL and HDL cholesterol in your blood as well as the levels of other lipids (fats) called triglycerides. A high level of triglycerides combined with either a high LDL level or a low HDL level is linked to the build-up of cholesterol inside your arteries. You will be asked not to eat (9-12 hours before your blood test, for this reason, these blood tests are normally done in the morning).

The results of your blood test will be compared to a range of normal levels of cholesterol. The ATP III guidelines categorise cholesterol levels as follows: [1]

• < 100 mg/ dL - Optimal
• 100-129 mg/dL - Near optimal/above optimal
• 130-159 mg/dL - Borderline high
• 160-189 mg/dL - High
• >190 mg/dL - Very high

There are several factors that increase your risk of high cholesterol and coronary artery disease. These are:

• Age: For men, being 45 years old and for women, being55 years old, increases your risk of high cholesterol, as your body systems age, reducing their ability to clear cholesterol from the blood.
• Gender
• Family history of early onset heart disease (in a first-degree male relative < 55 y or female relative < 65 y)
• Smoking: Smoking raises the levels of LDL (‘bad cholesterol) in your blood. If you quit smoking, your HDL (‘good cholesterol’) will go up, improving the ratio between LDL and HDL in your body.
• High blood pressure: People with high blood pressure commonly also have high cholesterol, as there are factors that connect both conditions such as poor diet, smoking and lack of exercise.
• Diabetes: Diabetes is often associated with other risk factors for high cholesterol, such as obesity, increased age and lack of exercise.
• Obesity: Obesity increases your level of triglycerides and LDL cholesterol and reduces your levels of the protective HDL cholesterol.
• Lack of exercise: Lack of exercise can increase fat deposition, which is a risk factor for high cholesterol.

Lifestyle changes

High cholesterol is often treated by cholesterol lowering medications and lifestyle changes.

The following lifestyle changes can help reduce high cholesterol:

• Lowering the intake of red meat, fatty foods, eggs, dairy, and fried foods
• Increasing your intake of fiber with fruits and vegetables.
• Use olive oil and canola oil instead of butter.
• Exercise 30 minutes daily if possible. Or exercise until you feel out of breath at least twice a week.
• Eat only whole grains not refined flour.
• Broil or bake meats.
• Eat more fish and poultry.
• Maintain normal weight/BMI.

Cholesterol lowering medications

There are a variety of medications that can be used to lower cholesterol, with statins being the most popular. Other medications may be prescribed for people who do not wish to take statins, or for people who are unsuitable  due to other pre-existing conditions.

Statins

Statins work by blocking an enzyme in the liver that is involved in making LDL cholesterol. Statins can reduce LDL levels by 25-60%. Most people find that low-intensity statins such as Simvastatin, Fluvastatin and Pravastatin are enough to help reduce their cholesterol. But some patients with very high cholesterol levels may need high-intensity statins such as Atorvastatin or Rosuvastatin.

Bile acid binders

Bile acid binders such as Cholestyramine, Colesevelam and Colestipol help to lower LDL by binding to the bile duct and helping to prevent the LDL from reaching the bloodstream where it can clog up the arteries.

Fibrates

Fibrates help to encourage the breakdown of VLDL (very-low-density lipoprotein), one of the types of LDL cholesterol. Fibrates also help to eliminate triglycerides from the blood. A high level of triglycerides and LDL is linked to a build-up of cholesterol inside the arteries. Gemfibrozil, Fenofibrate, Fenofibrate (micronized) and Fenofibric Acid are types of fibrate medication.

Nicotinic agents

Nicotinic agents, such as Niacin (Vitamin B3) lower the levels of triglycerides and LDL cholesterol, whilst raising the levels of HDL cholesterol. Of all the cholesterol-lowering drugs, nicotinic agents have the strongest effect on HDL levels.

Cholesterol absorption inhibitors

Cholesterol absorption inhibitors help to prevent cholesterol being absorbed from food by the intestines. Ezetimbe is an example of a cholesterol absorption inhibitor.

Apolipoprotein B antisense oligonucleotide

This type of medication blocks the production of a substance, that reduces the liver’s production of some harmful lipids (fats) including LDL. Mipomerson, is an example of an Apolipoprotein B antisense oligonucleotide.

MTP inhibitor

MTP inhibitors, such as Lomitapide, impair the absorption of lipids and also blocks the conversion of triglycerides into a substance called apo-B, which is involved in the production of VLDL (very low density lipoprotein) - a type of LDL cholesterol.

Omega 3 acids

Omega 3 is found in many foods and over-the-counter dietary supplements, however ASCEPA ® (icosapent ethyl) is the first prescription Omega-3, that has been clinically proven to lower high triglyceride levels without raising the levels of bad cholesterol.

Combination drugs

Combinations of statins with high blood pressure medications or other lipid-lowering medications can also be used to treat high cholesterol. Combination drugs are used when one anti-cholesterol drug isn’t working well enough, or if you have both high blood pressure and high cholesterol. These combination drugs include:

• Atorvastatin and Amlodipine  
• Lovastatin and Niacin (nicotinic acid)  
• Simvastatin and Niacin  
• Atorvastatin and Ezetimibe  
• Simvastatin and Ezetimibe