Hyperlipidemia is the condition of having elevated levels of cholesterols and or triglycerides in the blood. This is commonly known as having “high cholesterol.” While cholesterols are necessary for the proper functioning of the body, excessive amounts of this substance can cause detrimental effects to the body and are a substantial risk factor for cardiovascular disease. Cholesterol can deposit inside the lining of blood vessels and form plaques than can block the flow of blood and can cause consequences such as stroke or heart attack.
Blood tests measure the level of your lipids including total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides.
Total cholesterol and HDL cholesterol can be measured at any time of day and it is not necessary to be fasting. LDL cholesterol and triglycerides should be measured after fasting for at least 12 hours.
Total cholesterol — A high total cholesterol level may represent an increased risk of cardiovascular disease but decisions about to treat are usually based upon the level of LDL or HDL cholesterol.
- Less than 5.17 mmol/L (200 mg/dL) is normal.
- Level between 5.17 to 6.18 mmol/L (200 to 239 mg/dL) is borderline high.
- Level higher than 6.21 mmol/L (240 mg/dL) is high.
LDL (low density lipoprotein) cholesterol — The LDL cholesterol or "bad cholesterol" is a better predictor of cardiovascular disease and elevated LDL cholesterol levels elevate your risk of cardiovascular disease.
HDL (high density lipoprotein) cholesterol — HDL cholesterol is your “good” cholesterol. Higher levels of actually decrease or mitigate the risk of cardiovascular disease. A level greater than or equal to 1.55 mmol/L or 60 mg/dL is protective, while levels of HDL cholesterol less than 1.03 mmol/L or 40 mg/dL are lower than desired. There are no treatments for raising HDL cholesterol that has been proven to reduce the risk of heart attacks and strokes.
Triglycerides — High triglyceride levels are also associated with an elevated risk of cardiovascular disease, although this association is usually less relevant once other risks are factored in. Triglyceride levels are divided as follows:
- Normal - less than 1.69 mmol/L (150 mg/dL)
- Borderline high – Level between 1.69 to 2.25 mmol/L (150 to 199 mg/dL)
- High – Level between 2.25 to 5.63 mmol/L (200 to 499 mg/dL)
- Very high – Level higher than 5.65 mmol/L (500 mg/dL)
There are two main types of hyperlipidemia: primary and secondary.
- Primary hyperlipidemia or familial hyperlipidemia is due to genetic defects that lead to abnormalities in the production or metabolism of certain lipids. The genetic abnormalities can cause excessive production or decreased elimination of the lipids leading to accumulation of lipids in the blood.
- Secondary hyperlipidemia or acquired hyperlipidemia is due to other factors like medications, diet, or other medical conditions. Some causes of secondary hyperlipidemia include:
- Diabetes mellitus
- Unhealthy diet
- Thiazide diuretics
- Estrogen pills
Hyperlipidemia can cause deposition of cholesterol in the lining of blood vessels. The deposited cholesterol can form plaques that can affect the dynamics of blood flow. Plaques can obstruct the flow of blood to an organ. It can also can the vessels to lose its elasticity. Plaques can also rupture and can be thrown off in the blood stream in the form of an “embolus.” The embolus can float in the blood and later on lodge in the narrower blood vessels, effectively obstructing the flow of blood through that vessel. All these can lead to fatal conditions depending on which organ is compromised:
- Heart attack - If a plaque blocks the supply to the heart muscles, the heart muscles can die due to lack of oxygen supply.
- Stroke - If a plaque blocks the supply to the brain, or if an embolus is thrown to the brain, the brain can die due to lack of oxygen supply.
Hyperlipidemia itself has no symptoms. It is often detected only incidentally upon testing or only when detrimental sequelae are already present.
When to seek consult
Because hyperlipidemia has no symptoms, it is often ignored until it creates fatal conditions. Do not wait for the fatal complications to happen before you seek consult. In your regular health checkups, ask your doctor if you need to have your lipid levels tested. Doctors who would normally magage issues related to high cholesterol include Family doctors, Internal Medicine specialists, or Cardiologists.
Hyperlipidemia is diagnosed by a simple blood test: lipid profile test. This test will determine the levels of the various kinds of lipids in the blood. Your doctor will interpret these lipid levels in conjunction with the normal expected values.
Hyperlipidemia can be treated by medications and by lifestyle changes. Medications to treat hyperlipidemia include:
- Statins - include lovastatin, simvastatin, pravastatin, and others
- PCSK9 inhibitors — PCSK9 inhibitors are a new class of drugs that can lower LDL cholesterol levels. The PCSK9 inhibitors include evolocumab and alirocumab, which are given via injection every two to four weeks.
- Cholesterol absorption inhibitors - Ezetimibe (brand name: Zetia) limits the body's ability to absorb cholesterol from food.
- Bile-acid binding resins such as cholestyramine, colesevelam, and colestipol
- Fibrates - Fibrate medications (fenofibrate, gemfibrozil, and fenofibric acid) can decrease triglyceride levels and increase HDL cholesterol levels
Your doctor will prescribe one or a combination of these medications depending on your age, risk factors, and lipid levels. Individuals usually take these medications as maintenance medications. Hence, some of these have to be taken for months or years.
In addition to medications, lifestyle modifications are an important part of the treatment of hyperlipidemia. These can include:
- Healthy diet - Eat a high fiber diet. Eat whole grains, fruits, and vegetables. Avoid fatty foods especially those that are rich in saturated fat and trans fats. Eat foods that are rich in omega-3 fatty acids, which are good for the heart. This includes fishes like tuna, salmon, herring, and cod.
- Regular exercise - Regular exercise has been proven to improve cholesterol levels. As your health permits, aim to get at least 30 minutes of exercise a day.
- Weight loss - If you are obese, aim to lose weight. Obesity and hyperlipidemia are a bad combination for many metabolic complications including stroke and heart attack.
- Quit smoking - Smoking can increase your levels of cholesterol in the blood. Smoking can also cause your blood vessels to narrow, amplifying the negative effects of cholesterol on the blood vessels.