Written by Ada’s Medical Knowledge Team
It’s important you understand how cholesterol works. If you’re looking to learn more about cholesterol, then this is the article for you.
What is cholesterol?
- Production by the liver.
- Dietary cholesterol from the food you eat.
- Supporting cell membrane structure.
- Absorbing fat-soluble vitamins as a component of bile.
- Regulating cellular processes.
- Aiding vitamin D production.
- Producing hormones such as estrogen, testosterone, and cortisol.
Cholesterol is a lipophilic molecule, which means it is attracted to lipids, another word for fats. 1 Because of this, cholesterol cannot dissolve in blood. So it needs to be transported by molecules called lipoproteins. 5
There are different types of lipoproteins. These include: 2
- High-density lipoproteins (HDL)
- Low-density lipoproteins (LDL)
- Very low-density lipoproteins (VLDL)
HDLs and LDLs are the main lipoproteins involved in transporting cholesterol in the blood. 6
- LDL cholesterol, often nicknamed “bad cholesterol,” can be deposited in arterial walls, which can lead to the buildup of plaques, which can develop into atherosclerosis. 7
- HDL cholesterol, or “good cholesterol,” transports excess LDL cholesterol back to the liver for breakdown and removal from the body. 8
What causes high cholesterol?
- A family history of high cholesterol or atherosclerotic cardiovascular disease.
- Poor diet.
- Excess consumption of saturated fats, trans-fatty acids, and cholesterol.
- Being overweight.
- Alcohol consumption.
What cholesterol blood markers to watch out for?
The test for cholesterol levels is called a lipid profile. A lipid profile includes: 12
- Total cholesterol (TC)
- LDL cholesterol (LDL-C)
- HDL cholesterol (HDL-C)
- Non-HDL cholesterol (TC minus HDL-C)
- TC: <200 mg/dL
- LDL-C: <100 mg/dL
- HDL-C: ≥60 mg/dL
- Triglycerides: <150 mg/dL
The following lipid profile results indicate high cholesterol levels: 12
- TC: >200 mg/dL
- LDL-C: >100 mg/dL
- <40 mg/dL for men
- <50 mg/dL for women
- TC minus HDL-C <3.4 mmol/L (<130 mg/dL)
- Triglycerides >1.7 mmol/L (>150 mg/dL)
The results of a lipid profile can be affected by acute illness and inflammation. 12
Genetic testing can help confirm the diagnosis of inherited high blood cholesterol, or familial hypercholesterolemia. 12
What are the symptoms of high cholesterol?
- Atherosclerotic cardiovascular disease.
- Peripheral vascular disease.
The symptoms of these complications can include: 14
- Chest pain.
- Shortness of breath.
- Claudication, which is muscle pain following movement.
Which cholesterol medications are there?
- Statins, which slow down cholesterol production in the liver and increase LDL cholesterol removal from the bloodstream. These are the most commonly used cholesterol-lowering medications.
- Bile acid sequestrants, which help lower cholesterol by stopping the gut from reabsorbing bile acids. LDL cholesterol is broken down in this process.
- Niacin, or nicotinic acid, which can increase HDL-C while lowering LDL, TC, and triglycerides.
- Fibrates, which can lower triglycerides.
- Injectable medicines, including a new type of medication, called PCSK9 inhibitors, which are used to treat familial hypercholesterolemia.