Hyperlipidemias (HI-purr-LIP-id-EE-me-uhs) are disorders in which there are abnormally high levels of fatty substances called lipids—primarily cholesterol and triglycerides—in the blood. They increase the risk for atherosclerosis * and heart disease.
Hyperlipidemias are lipid metabolic *
Fats in the blood can come from food or from the liver, which manufactures cholesterol, triglycerides, and other fats. Fats in food are broken down and digested in the stomach and small intestine by a chemical called bile and by digestive enzymes * . These broken-down fats are then absorbed through the small intestine walls into the bloodstream for transport throughout the body. Cholesterol is used to build cells and certain hormones * . Triglycerides are stored in fat cells until the body needs to burn fats for energy.
Cholesterol and triglycerides are transported through the blood as part of particles called lipoproteins * :
About 98.9 million Americans age 20 and above have total blood cholesterol levels greater than the recommended maximum value of 200 milligrams per deciliter (mg/dL) of blood. Of these individuals, 31.9 million have high cholesterol, which is defined as levels equal to or greater than 240 mg/dL. High cholesterol puts people at high risk for coronary artery disease. This risk increases with age, since cholesterol levels usually rise as people get older.
Hyperlipidemias are more common in men than in younger women, because the female hormone estrogen tends to raise HDL levels. But after women go through menopause * and estrogen levels fall, their HDL levels decrease and their risk for hyperlipidemias increases.
Most hyperlipidemias are acquired conditions that come from other disorders such as diabetes or obesity. The other main category of hyperlipidemias, familial hyperlipidemias, result from certain gene mutations * . The two most common familial hyperlipidemias, familial combined hyperlipidemia and familial hypertriglyceridemia, occur in 1 percent of the population.
The primary cause of hyperlipidemias is a diet that is high in fat and cholesterol. Other factors that contribute to hyperlipidemias include:
Because acquired hyperlipidemias may have no symptoms until complications develop, they are generally detected through regular blood screenings. A fasting lipoprotein profile is recommended every five years beginning at age 20. Inherited hyperlipidemias and consequent heart disease usually develop at an earlier age than acquired hyperlipidemias.
A fasting lipoprotein profile measures total cholesterol, LDL cholesterol, HDL, and triglycerides to assess the risk of cardiovascular disease.
Treatment of hyperlipidemias aims to lower lipid levels in the blood to reduce the risk or slow the progression of atherosclerosis and heart disease and possibly reverse damage that has already occurred. A diet that is low in saturated fats and cholesterol and high in fruits and vegetables, along with regular exercise, is the frontline treatment. Losing weight and treating underlying diseases or conditions such as diabetes or high blood pressure are also important elements of treatment.
If lifestyle modifications are not sufficiently effective, medications that lower LDL cholesterol and/or triglycerides may be necessary. Statins are the most common and most effective drugs for treating high cholesterol. They lower LDL levels by slowing the rate at which cholesterol is produced in the liver. They can also slightly reduce triglycerides and raise HDL levels, and are the only lipid-lowering drugs proved to reduce the risk of heart attacks.
Other drugs for treating hyperlipidemias include the following:
To control cholesterol the daily diet should include no more than:
Since the body converts excess calories into triglycerides, not eating more calories than needed can help prevent hypertriglyceridemia. Doctors also recommend limiting simple carbohydrate (white bread, candy, doughnuts) intake, since these foods raise blood sugar levels quickly, triggering the release of large amounts of insulin, which raises triglyceride levels. In addition, regular exercise—30 minutes most days of the week—raises HDL and lowers LDL and triglycerides, so it plays an important role in preventing hyperlipidemias.
See also Metabolic Disease
Nardo, Don. Cardiovascular Disease and Diet. Farmington Hills, MI: Lucent Books, 2014.
Center for Young Women's Health. “Dietary Fat and Cholesterol.” http://youngwomenshealth.org/2012/12/10/dietary-fat-andcholesterol/ (accessed April 13, 2016).
MedlinePlus. “Triglycerides.” U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/triglycerides.html (accessed April 13, 2016).
American Heart Association. 7272 Greenville Ave., Dallas, TX 75231. Toll-free: 800-242-8721. Website: http://heart.org (accessed April 13, 2016).
National Heart, Lung, and Blood Institute. PO Box 30105, Bethesda, MD 20824-0105. Telephone: 301-592-8573. Website: http://www.nhlbi.nih.gov (accessed April 13, 2016).
* atherosclerosis (aah-thuh-roskluh-RO-suhs) is a condition in which plaque builds up in arteries. This can lead to narrowing and hardening of these arteries, which can slow or block blood flow to the heart and other organs and increase the risk of heart disease.
* metabolic (meh-tuh-BALL-ik) pertains to the processes in the body (metabolism) that convert food into energy and waste products.
* enzymes (EN-zimes) are proteins that trigger or speed up biochemical processes and reactions in the body.
* hormones are chemical messengers produced by various glands and sent into the bloodstream to act on certain body parts in specific ways.
* lipoproteins (LIE-po-PRO-teenz) are particles made of fats and proteins that transport cholesterol and triglycerides through the bloodstream. They are classified by their size and density. The larger lipoproteins are the least dense because they contain more fat relative to the amount of protein.
* obesity (o-BEE-suh-tee) is an excess of body fat. People are considered obese if their body mass index (BMI), is 30 or higher.
* syndrome is a group or pattern of symptoms or signs that occur together.
* risk factors are characteristics or events that increases the chance of developing a disease.
* high blood pressure, also called hypertension, is a condition in which blood being pumped by the heart through the arteries pushes against the artery walls with greater than normal force. This extra force can damage and weaken arteries and strain the heart, thereby increasing the risk of heart disease.
* menopause refers to the cessation of menstruation in women. Levels of the female hormone estrogen decline with menopause.
* gene mutations are changes in genes, which are the parts of deoxyribonucleic acid (DNA) molecules that transmit hereditary information from parents to their offspring.
* corticosteroids (kor-tih-ko-STEERoyds) are human-made drugs that resemble the hormone cortisol, which is produced by the adrenal glands in response to stress or low blood sugar. Cortisol raises blood sugar, decreases inflammation, and plays a role in metabolizing proteins, fats, and carbohydrates. Corticosteroid medications are usually given to decrease inflammation.
* diuretics (dye-yoor-EH-tiks) are medications that increase the body's output of urine.
* beta-blockers are drugs that lower blood pressure by blocking the effects of the hormone epinephrine. Epinephrine raises the heart rate, so blocking it reduces the heart rate and lessens the force with which blood flows through blood vessels.
* genetic (juh-NEH-tik) refers to heredity and the ways in which genes control the development and maintenance of living creatures.
* insulin is a hormone produced by beta cells in the pancreas that is critical for controlling blood glucose (sugar) levels. Insulin allows cells to take in glucose from the bloodstream and to use this glucose for energy. People who lack insulin or whose cells are resistant to insulin must inject it or must take medications that diminish insulin resistance.
* puberty (PU-ber-tee) is the period during which sexual maturity is attained.