Facts about and Definition of Triglycerides
Triglycerides are one of the types of fats (lipids) transported in the bloodstream. Most of the body's fat is also stored in the tissues as triglycerides. Triglyceride blood levels are commonly measured along with other lipid levels, such as cholesterol.
- Triglycerides are also present in foods like vegetable oils and animal fats. The triglycerides in our blood are a mixture of triglycerides obtained from dietary sources and triglycerides produced by the body as sources of energy.
- Elevated triglyceride levels can be caused by a variety of disease processes.
- Elevated triglyceride levels are considered to be a risk factor for developing hardening of the arteries (atherosclerosis) because many of the triglyceride-containing lipoproteins that transport fat in the bloodstream also transport cholesterol, a known contributor to atherosclerosis.
- Often, elevated triglyceride levels are present along with elevated cholesterol levels. This condition is referred to as a mixed hyperlipidemia.
What Is a Triglyceride Test?
Triglyceride levels in the blood are measured by a blood test. Fasting for 8 to 12 hours before the test is required, since recent eating and digestion can often cause the results to be temporarily elevated. Triglycerides can be measured as part of a lipoprotein panel or lipid panel in which cholesterol, HDL (high-density lipoprotein) and LDL (low-density lipoprotein) are also measured.
Normal Triglyceride Levels (Values)
According to the U.S. National Cholesterol Education Program, the guidelines for interpreting triglyceride levels are:
- Normal: <150 mg/dl
- Borderline to high: 150-199 mg/dl
- High: 200-499 mg/dl
- Very high: ≥500 mg/dl
Causes of Elevated (High, Abnormal) Triglyceride Levels
An elevated level of triglycerides in the blood is medically known as hypertriglyceridemia. Diseases that can lead to elevation of triglyceride levels include
- poorly-controlled diabetes,
- kidney disease,
- liver diseases including cirrhosis, obesity,
- some medications (for example, birth control pills, estrogens, beta-blockers, immunosuppressive medications), and
- familial (genetic) disorders of lipid metabolism.
Diet and Other Lifestyle Changes to Lower Triglycerides
Lifestyle modifications can be very effective in lowering blood triglyceride levels and are often the first-line treatment for borderline high levels. Lifestyle changes and self-care steps that have been proved to be effective in reducing triglyceride levels include
- weight loss,
- regular aerobic exercise,
- limiting intake of food with trans fats and saturated fats; substitute with polyunsaturated or monounsaturated fats rather than carbohydrates or sugar,
- reducing alcohol intake, and
- consuming fatty fish such ash mackerel, lake trout, herring, sardines, albacore tuna and salmon, which are high in omega-3 fatty acids.
It is important to control diabetes or other conditions that may be the underlying cause of elevated triglycerides. Reduction in other risk factors for cardiovascular disease, such as quitting smoking, is also important to decrease the risk of complications from elevated blood lipid levels.
Treatment for Elevated (High) Triglycerides
The treatment goals for any individual with elevated blood lipids must take into account the severity of the abnormalities and the specific lipid levels that are abnormal, as well the medical history and presence of additional risk factors for cardiovascular disease.
Treatments to reduce triglyceride levels are lipid altering medications, which are used to reduce levels of undesirable blood lipids, such as LDL cholesterol and triglycerides, and increasing blood levels of desirable lipids, such as HDL cholesterol. If triglyceride levels are extremely elevated, treatment may primarily address this problem in order to avoid pancreatitis (inflammation of the pancreas), which can be a complication of extremely high triglyceride levels.
There are different types of lipid altering medications, but only some of these are effective in lowering triglycerides.
Medications to Lower Triglyceride Levels
HMG CoA reductase inhibitors, fibric acide derivitaves, and nicotinic acid (Niacin) are classes of drugs that have effects on triglyceride levels.
- HMG CoA reductase inhibitor medications (statins) are most effective in lowering LDL cholesterol, mildly effective in increasing HDL cholesterol, and mildly effective in lowering triglycerides. Examples include pravastatin (Pravachol), lovastatin (Mevacor), atorvastatin (Lipitor), rosuvastatin (Crestor), and simvastatin (Zocor).
- Fibric acid derivative medications such as gemfibrozil (Lopid) and fenofibrate (Tricor) are most effective in lowering triglycerides, effective in increasing HDL, and minimally effective in lowering LDL levels.
- Nicotinic acid (Niacin), known by the names Niacin, Niaspan, or Slo-Niacin, is most effective in increasing HDL, effective in lowering triglycerides, and mildly to moderately effective in lowering LDL levels.
Omega-3 Fatty Acids to Lower Triglyceride Levels
Omega-3 fatty acids have also been shown to reduce triglyceride levels. The American Heart Association recommends eating fish (particularly fatty fish) at least two times (two servings) a week. If you have high triglyceride levels or other risk factors for cardiovascular disease, your health care professional may advise you to take omega-3 fatty acids in supplement (fish oil) form.
Harrison's Principles of Internal Medicine, 20th ed. (Vol.1 & Vol.2). McGraw-Hill Education 2018.
NIH. High Blood Triglycerides. NIH; National Heart, Lung, and Blood Institute. 2018.