Hypertriglyceridemia

Hypertriglyceridemia is an elevation of triglyceride levels in the bloodstream. Triglycerides are the main constituents in natural fats and oils and human body fat. In addition to the intake of dietary fats as a source of triglycerides, they are also produced by the liver. High concentrations of triglycerides in the blood are associated with increased risk of heart disease and stroke.

Hypertriglyceridemia is a common disorder in the United States, affecting 33% of the population.

It is attributed to consumption of a high-fat, high carbohydrate diet, the so-called Western diet. Elevated triglycerides and other lipids such as cholesterol are more common in industrialized countries in which the Western diet is consumed, rather than in developing countries where mainly whole foods, not refined foods, are consumed. Hypertriglyceridemia is even more damaging to overall health when accompanied by a sedentary lifestyle and low levels of physical activity. Triglyceride levels increase gradually in men until about age 50 and then decline slightly. In women they continue to increase with age.

Triglycerides are the main chemical constituent of more than 90% of dietary fats and body fat and are also produced in the body by the liver. These fats circulate constantly with other lipoproteins found in the blood, including:

Hypertriglyceridemia refers to elevated triglyceride levels in the blood. Using the Fredrickson classification of hyperlipidemias (elevated levels of all types of lipids), hypertriglyceridemia is classified into four different types:

Because elevated triglycerides are usually accompanied by elevations in other circulating fats, measurement of blood lipids (lipid profile) is usually sufficient for identifying hypertriglyceridemia. Laboratory tests are performed for total cholesterol, LDL, HDL, and triglyceride levels. The American Heart Association endorses the National Cholesterol Education Program (NCEP), a program of the National Institutes of Health (NIH), and supports its guidelines for the detection of high cholesterol. Normal results for lipids are as follows:

Additionally, the NCEP has identified triglyceride levels that can be used to determine whether hypertriglyceridemia treatment is required or if diet alone may lower levels sufficiently. The NCEP defines triglyceride levels as follows:

When triglyceride levels exceed 150 mg/dL, healthcare practitioners usually recommend a diet aimed at reducing lipid levels. Because there are different types of hypertriglyceridemia, which are often associated with other diseases or disorders (diabetes mellitus, obesity, metabolic syndrome), diets must be tailored individually. Individuals with hypertriglyceridemia are typically advised to lose weight and limit the consumption of processed and refined foods, simple sugars, alcohol, and saturated fats. Specific dietary guidelines for reducing triglyceride levels include:

Fats are molecules composed of two types of smaller molecules, glycerol and/or fatty acids. The three types of fats in the diet are saturated (including trans fats), monounsaturated, and polyunsaturated. Most foods contain several different types of fats, and some dietary fats are better than others for contributing to overall health. The three main types of fats are:

The National Heart, Lung, and Blood Institute (NHLBI), through its National Cholesterol Education Program (NCEP), recommends that the triglycerides of diabetic individuals be checked regularly. Diabetes can increase triglycerides significantly, especially when blood sugar is out of control. Healthy adults over age 40 should have a lipid profile performed at least once a year, and more often if triglyceride and cholesterol levels have been consistently high.

Fat restriction should be carefully evaluated. When weight loss occurs after reducing fat intake, triglyceride levels usually improve as body weight decreases. If triglycerides are severely elevated (1,000 mg/dL), a low-fat diet will decrease chylomicron and VLDL, but if triglycerides are only moderately elevated, a low-fat diet may increase these lipids and may also decrease HDL levels.

Women of childbearing age whose triglycerides are elevated before becoming pregnant are at risk for developing severe hypertriglyceridemia, with levels well above 1,000 mg/dL and the associated risk of pancreatitis. A woman with hypertriglyceridemia is advised to obtain counseling for diet, exercise, and weight management before becoming pregnant and requires close monitoring during pregnancy.

Hypertriglyceridemia has been found to be independently associated with the risk of developing cardiovascular disease and with multiple conditions that contribute to diabetes and metabolic syndrome. Medical experts agree that lowering elevated triglycerides is beneficial, and over certain levels essential. For a long time, triglycerides have been overshadowed by other blood lipids, especially choesterol, as contributing factors to cardiovascular disease. A Danish study involving 3,000 healthy men concluded that the risk of having a first heart attack was twice as high for men with the highest triglyceride levels as it was for those with the lowest levels. The connection between high triglycerides and heart disease is now established. The relationship between triglycerides and HDL, however, remains uncertain.

One way to keep triglyceride levels in check is to follow an antihypertriglyceridemia diet to reduce triglyceride levels to normal levels (less than 150 mg/dL), which will benefit the individual in a number of ways. Triglycerides carry fat-soluble vitamins A, D, E, and K to body organ systems that require them, help with the synthesis of certain hormones, and help protect cell membranes. The fat tissues in which they are stored also cushion and protect organs such as the kidneys and provide thermal insulation.

Unsaturated, monounsaturated, and polyunsaturated fats help to lower total and LDL cholesterol levels and are associated with a lower risk for heart disease. Polyunsaturated fats such as olive oil and canola oil are recommended for their effects on heart health by the Dietary Guidelines for Americans spon-sored by the National Institutes for Health (NIH). The dietary guidelines describe a healthy diet as one that includes a variety of vegetables (dark green leafy, red and orange, legumes, and starchy vegetables); whole fruits; grains, with at least half as whole grains; fat-free or low-fat dairy (milk, yogurt, cheeses) and soy beverages; and a variety of proteins, including seafood, lean meats, poultry, eggs, legumes, nuts, seeds, soy products, and oils such as olive oil and canola oil but not saturated fats or trans fats.

The American Heart Association (AHA) reports that omega-3 fatty acids benefit the heart by decreasing the levels of triglycerides, reducing the risk of arrhythmias and abnormal heartbeats that can lead to sudden death, and helping to lower blood pressure levels. Tips to limiting fat in the diet are focused on reducing foods high in saturated and trans fats. Guidelines offered by the Mayo Clinic include the following tips:

See also Dietary cholesterol ; Fats ; Low-fat diet ; Metabolic syndrome ; Metabolism ; Obesity ; Omega-3 and omega-6 fatty acids ; Protein ; Triglycerides ; Vitamins .