Hyperlipidemia is an elevation of lipids (fats) in the bloodstream. These lipids include cholesterol, cholesterol esters (compounds), phospholipids and triglycerides. They're transported in the blood as part of large molecules called lipoproteins.
These are the five major families of blood (plasma) lipoproteins:
- very low-density lipoproteins (VLDL)
- intermediate-density lipoproteins (IDL)
- low-density lipoproteins (LDL)
- high-density lipoproteins (HDL)
Types of Hyperlipidemia
When hyperlipidemia is defined in terms of a class or classes of elevated lipoproteins in the blood, the term hyperlipoproteinemia is used. Hypercholesterolemia is the term for high cholesterol levels in the blood. Hypertriglyceridemia refers to high triglyceride levels in the blood.
Causes and Risk Factors of Hyperlipidemia
Common secondary causes of hypercholesterolemia (specifically, high LDL cholesterol) include hypothyroidism (that is, low thyroid hormone levels), pregnancy, and kidney failure.
Common secondary causes of hypertriglyceridemia include diabetes, excess alcohol intake, obesity, and certain prescription medications (such as glucocorticoids and estrogen).
Hyperlipidemia, along with diabetes, hypertension (high blood pressure), positive family history, and smoking are all major risk factors for coronary heart disease.
Symptoms of Hyperlipidemia
Hyperlipidemia usually has no noticeable symptoms and tends to be discovered during routine examination or evaluation for atherosclerotic cardiovascular disease. However, deposits of cholesterol (known as xanthomas) may form under the skin (especially around the eyes or along the Achilles tendon) in individuals with familial forms of the disorder or in those with very high levels of cholesterol in the blood. Individuals with hypertriglyceridemia may develop numerous pimple-like lesions across their body. Extremely high levels of triglycerides may also result in pancreatitis, a severe inflammation of the pancreas that may be life-threatening.
Diagnosis of Hyperlipidemia
Diagnosis is typically based on medical history, physical examination, and blood tests (done after overnight fasting) in order to determine the specific levels of LDL cholesterol, HDL cholesterol, and triglycerides.
Treatment of Hyperlipidemia
It is necessary to first identify and treat any potential underlying medical problems, such as diabetes or hypothyroidism, that may contribute to hyperlipidemia. Treatment of hyperlipidemia itself includes dietary changes, weight reduction and exercise. If lifestyle modifications cannot bring about optimal lipid levels, then medications may be necessary.
Current national guidelines suggest a LDL cholesterol goal of <100 mg/dl for individuals already with heart disease or diabetes, <130 mg/dl for those with moderate risk of heart disease, and <160 mg/dl for everyone else. Your doctor can calculate your? Risk score? For heart disease.
Although there are no firm treatment targets for HDL cholesterol or triglycerides, most experts agree that optimal HDL cholesterol and triglyceride levels are >40 mg/dl and <200 mg/dl, respectively.