What is Cholesterol?
Cholesterol is a wax-like substance that circulates in the bloodstream. The body needs cholesterol to build, grow, and repair cells; however, high levels of cholesterol can cause cholesterol disease, which increases an individual’s risk of developing cardiovascular diseases.
What causes Hypercholesterolemia?
The liver produces cholesterol in the body, but an individual can also obtain cholesterol from the foods they eat. High cholesterol, also known as cholesterol disease, is caused by a buildup of plaques known as atherosclerosis in your blood vessels. The continuous growth of these plaques blocks the blood flow through major arteries in the body leading to fatal consequences.
High cholesterol levels can be attributed to both environmental and genetic factors. Though cholesterol disease is heritable, it is usually a consequence of an unhealthy diet, stress, and other choices that can be possibly avoided and prevented.
What are the different types of Hypercholesterolemia?
Lipoproteins are substances produced in the liver made from proteins and fat that transport cholesterol in the blood. There are two major types:
- Low-density lipoprotein (LDL): This type is often known as the “bad cholesterol” because it carries cholesterol to the arteries. If LDL levels in the blood are high, they are often a sign of cholesterol disease. High levels of LDL cause a buildup of fat deposits on the arteries. This can cause the narrowing of the arteries, which limits the blood flow to other areas of the body. According to the Centers for Disease Control and Prevention, approximately 33% of Americans have high LDL cholesterol levels.
- High-density lipoprotein (HDL): This type is often known as the “good cholesterol” because it helps remove LDL from the body back to the liver and can potentially reverse the buildup of plaques in the arteries. Studies have demonstrated that desirable levels of HDL are associated with lower risks of cardiovascular disease.
There are certain risk factors that can increase an individual’s likelihood of developing cholesterol disease. These factors include:
- Obesity: It has been demonstrated that an increased body mass index (BMI) of 30 or above impedes the clearance of LDL from your blood and allows for the buildup of plaques in the arteries.
- Poor diet: Consumption of food with saturated fat and trans fat can increase your cholesterol levels, specifically LDL levels. Moreover, the consumption of food that contains cholesterol will also contribute to increased cholesterol levels.
- Lack of physical activity: Daily physical activity helps increase the production of “good cholesterol” or HDL in the body. Therefore, lack of physical activity is associated with increased LDL levels.
- Age: Aging is a debilitating process and causes many changes to the body, one of which is related to less liver clearance of LDL cholesterol. Thus, LDL levels are likely to climb as we age.
- Comorbidities: Certain comorbidities such as type II diabetes is linked to cholesterol disease. T2DM, a condition based on high blood glucose, causes damage to arteries and contributes to an increase in levels of dangerous cholesterol named low-density lipoprotein.
- Family history: If one or more of your family members are diagnosed with either cholesterol or cardiovascular disease, then that contributes to an increased risk of developing cholesterol disease.
- Genetics: Familial hypercholesterolemia is a genetic disease that causes high cholesterol levels. The basis of the disease is a mutation in either the LDL receptor gene, variant of the PCSK9 gene, or APOB gene.
High levels of cholesterol are preventable and avoidable, through these measures:
- Eat good fats and avoid foods with bad fats
- Maintain a healthy diet and lifestyle
- Quit smoking
- Moderate alcohol intake
- Lower stress levels
Cholesterol disease causes a buildup of fat deposits that block the flow of blood in arteries, which can lead to severe complications. If left untreated, cholesterol disease is estimated to cause more than 2 million deaths annually, according to the World Health Organization.
These complications include:
- Angina: The narrowing of the arteries can cause chest pain known as angina due to the limited blood supply.
- Peripheral arterial disease (PAD): This is most common in arteries around the legs or kidneys and reduced blood supply can lead to PAD.
- Heart Attack: If the artery is completely clogged and blood flow stops, then you can have a heart attack.
- Stroke: If the artery that transports oxygen and important nutrients is completely obstructed, then blood flow to the brain stops, and you can have a stroke.
Symptoms and Diagnosis
There is no set of symptoms of cholesterol disease. Routine blood tests are the only diagnosis for cholesterol disease. This blood test is known as a lipid panel that reports four essential parameters: total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides in units of milligrams per deciliter (mg/dL). It is preferable that patients fast between nine to twelve hours before the test. These blood tests will be frequently performed depending on the risk factors discussed above and the physician’s recommendations.
As a general guideline, the box below shows the desirable values for each parameter based on the Centers for Disease Control and Prevention. However, it is crucial for patients to see physicians and refrain from attempting to diagnose themselves.
Parameter Values Results
Total Cholesterol (mg/dL) < 200 mg/dL is Desirable
LDL Cholesterol (mg/dL) < 70 mg/dL is Best but <100 mg/dL is Optimal
HDL Cholesterol (mg/dL) 40-59 mg/dL in men and 50-59 mg/dL in women
Triglycerides (mg/dL) < 150 mg/dL is Desirable
Cholesterol ratio is the ratio that indicates your likelihood of developing cardiovascular diseases. This ratio is calculated by dividing your total cholesterol by your HDL cholesterol. According to the American Heart Association, a desirable ratio is around 3.5, but anything below 5 is acceptable. Therefore, a higher ratio means a higher risk of heart disease.
The first line of treatment to combat high levels of cholesterol include easy changes to diet and frequent exercise. Nevertheless, if these changes have been made, and levels remain high, then a more potent treatment is needed, such as medications.
The type of medications is based on multiple factors and depends on the risk factors such as gender, age, medical history, and side effects. Common classes of drugs include:
- Statins (HMG-CoA reductase inhibitors): These drugs are the gold-standard treatment, introduced around the 1980s, and target the liver’s production of cholesterol. Frequent medications used in this class include atorvastatin (Lipitor), lovastatin (Altoprev), rosuvastatin (Crestor), and pravastatin (Pravachol).
- Fibrates: This class of drugs targets triglycerides by removing them from the blood and reducing VLDL. Frequent medications used in this class include fenofibrate (TriCor) and gemfibrozil (Lopid).
- Niacin: This class of drugs, vitamin B, aims to lower the production of LDL and VLDL. However, there have been significant side effects of the use of this medication, such as liver damage. This is vitamin B3, but Niacin supplements come in three forms that include nicotinic acid, nicotinamide, and inositol hexanicotinate.
- PCSK9 inhibitors: This class of drugs inactivates an important protein that lowers LDL levels in the blood. Frequent medication used in this class is repatha (evolocumab) and praluent (alirocumab).
- Cholesterol absorption inhibitors: This class of drugs focuses on reducing the absorption of cholesterol from food. Frequent medication used in this class is the ezetimibe (Zetia), which can be used in combination with a statin.
- Bile-acid Sequestrants: This class of drugs aims to increase the production of bile acids from cholesterol, which in turn lowers the levels of cholesterol in the blood. Frequent medications used in this class include colestipol (Colestid), cholestyramine (Prevalite), and colesevelam (Welchol).
- Bempedoic acid: This is the newest class of drugs recently approved by the Food and Drug Administration in February of 2020. Bempedoic acid decreases LDL levels and increases the absorption of cholesterol. It has been recommended to take this in combination with statins. However, potential side effects have been associated with this class of drugs such as gout, kidney stones, and tendon rupture. Two medications that were approved are Nexletol and Nexlizet.
Alternative Medicine Options
There has been evidence surrounding the potential use of natural substances to lower cholesterol levels. It is advisable to check with your physician regarding what is recommended. These substances include red yeast rice, oat bran, and barley.
Cholesterol disease is caused by an accumulation of fat deposits (atherosclerosis)that reduce the blood flow in arteries and can cause life-threatening complications and possibly death. Certain risk factors, such as poor diet and lack of exercise, can contribute to an increased chance of the development of cholesterol disease. Therefore, vigilance and continuous monitoring are important to detect any minor changes. Cholesterol disease is preventable with appropriate lifestyle modifications, and patients need to attempt to make those changes prior to any treatment with medications.
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Consumer Reports; Drug Effectiveness Review Project (March 2013). “Evaluating statin drugs to treat High Cholesterol and Heart Disease: Comparing Effectiveness, Safety, and Price” (PDF). Best Buy Drugs. Consumer Reports: 9. Retrieved 27 March 2013.
Vincent, Melissa J.; Allen, Bruce; Palacios, Orsolya M.; Haber, Lynne T.; Maki, Kevin C. (2019-01-01). “Meta-regression analysis of the effects of dietary cholesterol intake on LDL and HDL cholesterol”. The American Journal of Clinical Nutrition. 109 (1): 7–16. doi:10.1093/ajcn/nqy273. ISSN 0002-9165.
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