Dyslipidemia: what is it, symptoms, how to treat, nutrition

What is dyslipidemia?

Dyslipidemia(hyperlipidemia) Is a high level of lipids (cholesterol, triglycerides, or both) or low level of high density lipoprotein (HDL) cholesterol.

Lipoproteins - particles of proteins and other substances. They contain fats such as cholesterol and triglycerides that cannot circulate freely in the blood.

There are different types of lipoproteins, including:

• chylomicron;
• very low density lipoproteins (VLDL);
• low density lipoprotein (LDL);
• high density lipoproteins (HDL).

Levels of lipoproteins, and therefore lipids, in particular low-density lipoprotein (LDL) cholesterol, increase slightly with age. Levels are usually slightly higher in men than in women, but levels in women increase after menopause. The increase in lipoprotein levels that occurs with age can lead to dyslipidemia.

As total cholesterol levels rise, the risk of developing atherosclerosis increases, even if the level is not high enough to cause dyslipidemia.

Atherosclerosis can affect arteries that supply blood to the heart (causing coronary artery disease), arteries that supply blood to the brain (causing stroke), and the arteries supplying the rest of the body (causing peripheral arterial disease). Hence, high total cholesterol levels also increase the risk heart attack or a stroke.

Low total cholesterol is generally considered better than high. However, very low cholesterol levels (hypolipidemia) can also be unhealthy.

Although there is no natural limit between normal and abnormal cholesterol levels, a total cholesterol level of less than 200 milligrams per deciliter of blood (mg / dL) is desirable for adults. And many people benefit from keeping lipid levels even lower. In some parts of the world (such as China and Japan) where the average cholesterol level is 150 mg / dL, coronary heart disease occurs less often than in countries such as Russia, the United States. The risk of heart attack more than doubles when total cholesterol levels approach 300 mg / dL.

Total cholesterol levels are only a general guide to the risk of atherosclerosis. The levels of total cholesterol components, especially LDL and HDL cholesterol, are more important. High LDL (bad) cholesterol increases your risk. High HDL (good) cholesterol is generally not considered a disorder because it lowers the risk of atherosclerosis. However, low HDL cholesterol (defined as less than 40 mg / dL) is associated with an increased risk of cardiovascular disease. Experts believe an LDL cholesterol level of less than 100 mg / dL is desirable.

Whether elevated triglycerides increase the risk of heart attack or stroke is unclear. Triglyceride levels above 150 mg / dL are considered abnormal, but high levels do not appear to increase risk in all people. For people with high triglyceride levels, the risk of heart attack or stroke is increased if they also have low good cholesterol levels. diabetes, chronic kidney disease or many close relatives who have had atherosclerosis (family history).

High levels of HDL, the good cholesterol, can be beneficial and is not considered a disorder. Too low HDL levels increase the risk of atherosclerosis.

Lipoprotein is a combination of LDL with an additional protein added to it. Levels above about 30 mg / dL (or 75 nmol / L) are associated with an increased risk of atherosclerosis. High levels are often inherited. Lipoprotein does not depend on nutrition or most lipid-lowering drugs. Usually it only needs to be measured once.

Causes and risk factors for dyslipidemia

The factors that cause dyslipidemia are divided into:

• Primary: genetic (hereditary) causes;
• Secondary: lifestyle and other reasons.

Both primary and secondary causes contribute to dyslipidemia to varying degrees. For example, a person with hereditary hyperlipidemia may have even higher lipid levels if the person also has secondary causes of hyperlipidemia.

Primary (hereditary) dyslipidemia

Primary causes include gene mutations that cause the body to produce too much LDL cholesterol or triglycerides, or mutations that affect the removal of these substances from the body. Some causes include underproduction or excessive removal of HDL cholesterol. Primary causes tend to be inherited and thus spread across families.

Cholesterol and triglyceride levels are highest in people with primary dyslipidemias, which affect the body's metabolism and lipid excretion. People can also inherit a tendency for their HDL cholesterol levels to be unusually low.

The consequences of primary dyslipidemia may include premature atherosclerosis, which can lead to angina pectoris or heart attacks. Peripheral artery disease is also a consequence, often resulting in decreased blood flow to the legs, with pain when walking. Stroke is another possible consequence. Very high triglyceride levels can cause pancreatitis.

In people with a genetic disorder that causes elevated triglyceride levels (for example, familial hypertriglyceridemia or familial combined hyperlipidemia), certain disorders and substances can raise triglycerides to extremely high levels. Examples of disorders include poorly controlled diabetes mellitus and kidney disease. Examples of substances include excessive alcohol consumption and the use of certain drugs, such as estrogens (taken by mouth), which increase triglyceride levels.

Symptoms may include body fat (eruptive xanthomas) in the skin on the front of the legs and the back of the arms, enlarged spleen and liver, abdominal pain and decreased sensitivity to touch due to nerve damage. These disorders can cause pancreatitis, which is sometimes fatal.

Limiting your fat intake (to 50 grams per day) can help prevent nerve damage and pancreatitis. Losing weight and stopping alcohol will also help. Lipid-lowering drugs may also be effective.

- Lipoprotein lipase deficiency and apolipoprotein C2 deficiency.

Lipoprotein lipase deficiency and apolipoprotein C2 deficiency are rare disorders caused by a lack of certain proteins required to remove triglyceride-containing particles. In these disorders, the body is unable to remove chylomicrons from the bloodstream, resulting in very high triglyceride levels. Without treatment, levels often well exceed 1000 mg / dL.

Symptoms appear during childhood and early adolescence. These include recurring bouts of abdominal pain, enlarged liver and spleen, and pinkish yellow bumps on the skin on the elbows, knees, buttocks, back, front of the legs, and back of the arms. These rashes, called eruptive xanthomas, are deposits of fat. Eating fat makes symptoms worse.

Although the disorder does not lead to atherosclerosis, it can cause pancreatitis, which is sometimes fatal. People with this disorder must strictly limit the amount of all types of fat - saturated, unsaturated, and polyunsaturated - in their diet. People may need to take vitamin supplements to make up for nutrient deficiencies in their diet. Several treatments for lipoprotein lipase and apolipoprotein C2 deficiency are under development.

- Familial hypercholesterolemia.

At familial hypercholesterolemia total cholesterol rises. People can inherit one abnormal gene, or two abnormal genes, one from each parent. People who have two abnormal genes (homozygotes) are more affected than people who have only one abnormal gene (heterozygotes).

Approximately 1 in 200 people are heterozygotes, and 1 in 250,000 - 1 in 1 million people are homozygous. Affected people may have fatty deposits (xanthomas) in tendons in the heels, knees, elbows, and fingers. Rarely, xanthomas appear by age 10.

Familial hypercholesterolemia can lead to rapidly progressive atherosclerosis and early death due to coronary artery disease. Children with two abnormal genes can have a heart attack or angina by age 20, and men with one abnormal gene often develop coronary artery disease by age 30-50. Women with one abnormal gene are also at increased risk, but the risk usually begins about 10 years later than men. People who smoke or have arterial hypertension, diabetes or obesitymay develop atherosclerosis even earlier.

Treatment for familial hypercholesterolemia begins with a diet low in saturated fat and cholesterol. It is recommended to lose weight, quit smoking and increase physical activity if necessary. One or more lipid-lowering drugs are usually required. Some people need apheresis, a method of filtering blood to lower LDL levels. Some people with homozygous familial hypercholesterolemia may benefit from liver transplants. Early diagnosis and treatment can reduce the increased risk of heart attack and stroke.

- Familial combined hyperlipidemia.

In familial combined hyperlipidemia, levels of cholesterol, triglycerides, or both may be high. This disorder affects 1-2% of people. Lipid levels usually become abnormal after age 30, but sometimes at a younger age, especially in people who are overweight, have a high fat diet, or metabolic syndrome.

Treatment for familial combination hyperlipidemia includes limiting the intake of saturated fat, cholesterol, and sugar, as well as exercise and, if necessary, weight loss. Many people with the disorder must take lipid-lowering drugs.

- Familial dysbetalipoproteinemia.

In familial dysbetalipoproteinemia, levels of very low density lipoproteins (VLDL) and total cholesterol and triglycerides are high. These levels are high because an unusual form of VLDL builds up in the blood. Fat deposits (xanthomas) can form in the skin above the elbows and knees and in the palms of the hands, where they can cause yellow folds. This unusual condition leads to the early development of severe atherosclerosis. In middle age, atherosclerosis often leads to blockage of the coronary and peripheral arteries.

Treatment of familial dysbetalipoproteinemia includes reaching and maintaining the recommended body weight and limiting the intake of cholesterol, saturated fat and carbohydrates. It is also necessary to take lipid-lowering drugs. With treatment, lipid levels can be improved, the progression of atherosclerosis can be slowed down, and fatty deposits on the skin can become less or disappear.

- Familial hypertriglyceridemia.

In familial hypertriglyceridemia, triglyceride levels increase. This disorder affects about 1% of people. In some families affected by this disorder, atherosclerosis tends to develop at a young age. When applicable, weight loss and alcohol restriction and carbohydrates often reduce triglycerides to normal levels. If these measures are ineffective, the use of a lipid-lowering drug can help. For people who also have diabetes, good diabetes control is important.

- Hypoalphalipoproteinemia.

With hypoalphalipoproteinemia, HDL cholesterol is lowered. Low HDL cholesterol levels are often inherited. Many different genetic abnormalities can cause low HDL cholesterol. Because drugs that increase HDL cholesterol do not reduce the risk of atherosclerosis, hypoalphalipoproteinemia is treated by lowering LDL cholesterol.

Secondary dyslipidemia

Secondary causes contribute to many cases of dyslipidemia.

The most important cause of secondary dyslipidemia is:

• a sedentary lifestyle with excessive consumption of saturated fat, cholesterol, and trans fats.

Some other common secondary causes include:

• diabetes;
• consuming large amounts of alcohol;
• chronic kidney disease;
• hypothyroidism;
• primary biliary cirrhosis;
• taking certain medications.

Some people are more sensitive to the effects of diet than others, but most suffer from the effects in one way or another. One person can eat large amounts of animal fat, and the total cholesterol level does not rise above the desired level. Another person can follow a strict low-fat diet and their total cholesterol will not fall below the high level. This difference appears to be mainly due to genetics.

A person's genetic makeup affects the rate at which the body produces, uses, and removes these fats. Plus, body type doesn't always predict cholesterol levels. Some overweight people have low cholesterol levels and some thin people have high cholesterol levels. Eating extra calories can lead to high triglyceride levels, as well as high alcohol consumption.

Some disorders cause lipid levels to rise. Poorly controlled diabetes or chronic kidney disease can lead to high total cholesterol or triglycerides. Certain liver diseases (especially primary biliary cirrhosis) and insufficient activity of the thyroid gland (hypothyroidism) can lead to an increase in total cholesterol levels.

Use of drugs such as estrogens (taken by mouth), oral contraceptives, corticosteroids, retinoids, thiazide diuretics (to some extent), cyclosporine, tacrolimus, and antiviral drugsused to treat human immunodeficiency virus (HIV) and AIDS, may increase cholesterol and / or triglyceride levels.

Cigarette smoking, HIV infection, poorly controlled diabetes, or kidney disease (such as nephrotic syndrome) can help lower good cholesterol levels. Medications such as beta blockers and anabolic steroids can lower HDL levels.

Signs and symptoms of dyslipidemia

High blood lipids usually do not cause symptoms. Sometimes, when levels are particularly high, fat is deposited in the skin and tendons and forms bumps called xanthomas. Sometimes people develop opaque white or gray rings at the edge of the cornea.

Very high triglyceride levels can cause an enlarged liver or spleen, a tingling or burning sensation in the hands and feet, difficulty breathing and confusion and may increase the risk of developing pancreatitis. Pancreatitis can cause severe abdominal pain and is sometimes fatal.

Diagnosis of dyslipidemia

To diagnose dyslipidemia, levels of total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides (lipid profile) are examined. Because eating or drinking can cause a temporary rise in triglyceride levels, people should abstain for at least 12 hours before taking a blood sample.

When blood lipid levels are very high, special blood tests are done to check for the specific underlying disorder. Specific disorders include several inherited disorders (primary dyslipidemias) that cause different lipid abnormalities and have different risks.

Dyslipidemia treatment

Usually the best treatment for people is to lose weight if they are overweight, quit smoking if they smoke, reduce the total saturated fat and cholesterol in the diet, increase physical activity, and then, if necessary, take lipid-lowering drugs.

Regular physical activity can help lower triglycerides and raise HDL cholesterol. An example is brisk walking for at least 30 minutes a day.

Lipid-lowering drugs may be given to some patients with very high lipid levels who do not respond to dietary changes, especially those with familial hypercholesterolemia.

- Lipid-lowering diet.

A diet low in saturated fat and cholesterol can lower LDL cholesterol. However, people with high triglyceride levels should also avoid consuming large amounts of sugar (whether in foods or drinks). refined flours (such as those used in most commercial baked goods) and starchy foods (such as potatoes and rice).

The type of fat consumed is important. Fats can be saturated, polyunsaturated, or monounsaturated. Saturated fat raises cholesterol levels more than other forms of fat. Saturated fat should provide no more than 5-7% of the total calories consumed per day. Polyunsaturated fats (which include omega-3 fats and omega-6 fats) can help lower triglycerides and LDL in the blood. The fat content of most foods is indicated on the packaging.

High amounts of saturated fat are found in meat, egg yolks, fatty dairy products, some nuts (such as macadamia nuts), and coconut. Vegetable oils contain less saturated fat, but only a few.

Margarine, which is made from polyunsaturated vegetable oils, is usually a healthier substitute for butter that is high in saturated fat (about 60%). However, some margarine-containing foods contain trans fats that can raise LDL cholesterol (bad) and lower HDL cholesterol (good). Margarines, made primarily from liquid butter, are lower in saturated fat than butter.

It is recommended that you eat lots of vegetables, fruits, and whole grains that are low in fat and do not contain cholesterol. Foods rich in soluble fiber are also recommended, which bind fats in the intestines and help lower cholesterol. Such foods include oat bran, oatmeal, beans, peas, rice bran, barley, citrus fruits, strawberries, and apple pulp. Psyllium (Ispagula), usually taken to relieve constipationmay also lower cholesterol.

- Lipid-lowering drugs.

Treatment with lipid-lowering drugs depends not only on lipid levels, but also on the presence coronary heart disease, diabetes, or other major risk factors for coronary arteries. For people with coronary artery disease or diabetes, the risk of heart attack or stroke can be reduced with lipid-lowering drugs called statins. People with very high cholesterol levels or other risk factors for heart attack or stroke may also benefit from lipid-lowering drugs.

There are different types of lipid-lowering drugs:

• Statins;
• Cholesterol absorption inhibitors;
• Bile acid binder;
• PCSK9 inhibitors;
• Fibric acid derivatives;
• Supplements of omega-3 fats;
• Niacin.

Each type lowers lipid levels in a different way. Therefore, different types of drugs have different side effects and can affect lipid levels in different ways. A diet low in saturated fat is recommended.

Lipid-lowering drugs do more than lower lipids - they help prevent coronary artery disease. In addition, statins have been shown to reduce the risk of early death.

People with very high triglyceride levels and a risk of pancreatitis may need both dietary changes and and drugs that lower triglycerides, usually fibrate or omega-3 fatty acids, dispensed by recipe.

- Procedures to lower cholesterol.

Cholesterol-lowering medical treatments are for people with very high LDL cholesterol who do not respond to diet and lipid-lowering drugs. These people include people with familial hypercholesterolemia. LDL apheresis is the most commonly performed procedure. LDL apheresis is a non-surgical procedure in which a special machine draws blood from a person and then separates the LDL component from the rest of the blood. The blood (minus the LDL component) is then returned to the person.

- Treatment of the causes of high cholesterol.

Any medical conditions that cause or are risk factors for high cholesterol should also be treated. Therefore, people with diabetes must carefully monitor the level of blood glucose. Kidney disease, liver and hypothyroidism are also treated. If a drug is causing your cholesterol to rise, doctors may lower the dose of the drug or prescribe a different drug.