Dyslipidemia

Epidemiology

Lipid abnormalities are the big concern in modern days, and their association with cardiovascular diseases and atherosclerosis is well established. Their prevalence is increasing all over the world for the last few decades, but many large medical studies have shown us that this sole, but relevant problem can be modified. In the United States, the prevalence is also very high, and it is getting larger and larger every year. It’s estimated that the 53 % of the US population have lipid abnormalities, 23% have low HDL (the good cholesterol), while 27% have high LDL (the bad cholesterol), and over 30% people have a high level of triglycerides (body fat used for energy).

Often called hyperlipidemia or the high cholesterol in clinical practice, dyslipidemia is the term that is more related to high level of Low-density lipoprotein Cholesterol (LDL-C) and triglycerides opposed to the low level of High-density lipoprotein Cholesterol (HDL-C).

dyslipidemia

Lipoproteins

So what are lipoproteins actually? They are big macromolecular complexes with many different roles such as resorption of cholesterol, long chain fatty acids, and fat-soluble vitamins; the transport of cholesterol, triglycerides, and fat-soluble vitamins from the liver to peripheral tissues, and transport from peripheral tissues to liver back. So they are not your enemy. Lipoproteins are natural products of your organism with an important function, but the problem is introduced when their balance changes. These particles are in spherical shape and are made of lipids and specific proteins – apolipoproteins. The exterior, polar part of the spherical particle is made of free cholesterol, apolipoproteins, and phospholipids. While the interior (the central part) includes cholesteryl esters and triglycerides. Lipoproteins come in various sizes, and their distinction relies on density and apolipoprotein and lipid type. Classification by density separates:

Chylomicrons

Very low-density lipoproteins – VLDL

Intermediate density lipoproteins – IDL

Low-density lipoproteins – LDL

High-density lipoproteins – HDL

Chylomicrons and VLDL have a function of transporting the triglycerides, while the LDL and HDL are responsible for transporting the cholesterol. HDL move cholesterol from peripheral tissues. It’s called good cholesterol because it cleans the blood from the excess of cholesterol deposits. The LDL move cholesterol from the liver to blood vessels, muscles, and heart. If it’s in higher concentration, it leads to atherosclerosis.

Cholesterol in itself is not bad for your health. Some of the cholesterol is made in your organism and some is ingested via food. Approximately 2/3 of all cholesterol is made in body and 1/3 comes through the food, but the other one is where you can make a mistake and overflow your blood with unnecessary fat. Anyway, you can’t possibly live without cholesterol, because it is incorporated in every cell structure in the cell membrane and intracellular membrane. It is important for the synthesis of sex hormones, bile acids in hepatocytes, and for transporting of fat-related substances mentioned above.

Dyslipidemia is an insidious condition. There are no shown symptoms to this disorder, and years can go by before you are diagnosed with it. Today is recommended that the best way to postpone atherosclerosis for the later part of your life is to live your life by the formula of 0, 3, 5, 140, 5, 3, 0, where those numbers mean:

0 – a life without smoking

3 – 3 km of walking daily (1.86 miles)

5 – 5 of a smaller meals during the day

140 – systolic pressure under 140 mm Hg

5 – total cholesterol under 5

3 – LDL – C lower than 3

0 – absence of obesity and diabetes

Diagnosis

Dyslipidemia diagnosis is based on a serum lipid concentration which is measured in the morning on an empty stomach. It is important that there was no big difference in a weight change, because if you lost weight some of the fat is relocated from adipocytes to blood, and it does not correspond to clear picture of lipid concentration in serum. The inquiry of lipid status represents the measurement of total cholesterol, LDL, HDL, and triglycerides. Elevated values for total cholesterol are the ones > 6.28mmol/L, for LDL > 4.11 mmol/L, for triglycerides > 2.28 mmol/L while the concentration for HDL should be kept between 1.03 – 1.55 mmol/L.

Levels of lipids in bloodstream

If the total cholesterol is in range between 5.0 – 6.4 mmol/L the low hypercholesterolaemia is recognized

6.5 – 7.5 mmol/L indicates the moderate hypercholesterolaemia,

 and concentration in blood >7.5 mmol/L represents the high hypercholesterolaemia

Desirable levels of cholesterol in blood are:

< 4.5 for people at high risk, and

< 4.0 for people at very high risk

recommended concentration for LDL is < 3 mmol/L

2.5 mmol/L for people who are at high risk, and

< 1,8 mmol/L for people under very high risk

recommended value for triglycerides in blood is < 1.7 mmol/L

Desirable levels for HDL are

> 1.0 mmol/L for men, and

> 1.3 mmol/L for women

You can’t really have a surplus of HDL. Here goes the rule – the more the better. Some people are even lucky enough to have a higher concentration of HDL intrinsically.

Recommendations

United States preventive services task force recommend:

  • Checking your serum lipid levels on a regular basis if you are 45 or older female or 35 years or older male person. People with a risk for cardiovascular diseases should be treated according to test results.
  • Blood tests are recommended to younger persons of 20 – 45 years for females and 20 – 40 years for males if they have cardiovascular disease risks. This includes persons with diabetes, family history of heart diseases in male relatives younger than 50 years or female relatives younger than 60 years, people with family history of hyperlipidemia or personal medical history of several heart disease factors (smoking, hypertension…).
  • There are no recommendations for stopping the testing at a particular age or lifestyle.
  • Testing should be conducted even for the older people who had never done any testing, although the sequential testing is not needed because the lipid levels will not increase so much after the age of 65.
  • The optimal time range between two testing is not definitely specified, but it’s usually done on every 5 years, with narrower intervals in case of patients with abnormal levels and with wider intervals with low risk or normal serum lipid levels.

Types

Primary types of dyslipidemia are caused by one or multiple gene mutation which changes the way of apolipoprotein production or elimination. Specifically to hyperproduction and inadequate elimination of LDL as well as triglycerides, and hypoproduction or over-elimination of HDL. The doctors suspect primary dyslipidemia when a family history of early diagnosed atherosclerosis exists, atherosclerosis has appeared before the age of 60, or the cholesterol levels are > 6.2 mmol/L. There are various possibilities in gene changes, but these changes appear in children almost every time, rarer in older age.

Secondary dyslipidemia comes in older age, and it is caused by various reasons. The main one is a sedentary way of life and an unhealthy diet with a lot of cholesterol, saturated fats, and trans fats income. Trans fats are an utterly bad thing. They have no nutritional value but are often used in the processed food industry. They are made by adding H atoms in unsaturated fats which changes the appearance of the chemical structure. They have a big potential for causing atherosclerosis and should be avoided by any chance mean. The other causes include diabetes (increases the VLDL apolipoprotein synthesis in the liver), obesity, lipodystrophy, renal insufficiency, hepatitis, low thyroid hormones, and some drugs.

Treatment

Before you will get any type of prescriptions, your doctor will suggest you to change the way of your life. A healthy diet and physical exercises are your best friends in lowering LDL and triglycerides. They are always recommended before any medicines. Your diet should be well balanced, which means protein intake of 15 – 20%, fat intake less than 35% where saturated fats are kept under 7%, and carbohydrate intake of 45 – 50% of your daily diet. We are talking about the healthy carbohydrates here. Avoid refined sugar such as one in sweets, cakes, fizzy drinks, and eat more whole grain bread, rice, fruits, and vegetables. Try to eat fish meals at least 2 times a weak, especially the blue sea fish which is rich in healthy omega 3 fatty acids. Avoid full-fat cheese, egg yolks, lard, margarine, fried potatoes… The meat should be cooked, not fried, lean meat is recommended. Generally, a Mediterranean diet is what you should aim for. It is based on olive oil use, moderate use of fish, a low intake of red meat, and a high intake of fruits and vegetables.

Make a habit of doing exercises according to your age and physical possibilities. The least you could do is to try walking 30 minutes every day. It does not take much, but it helps a lot. Physical activity increases the production of good HDL cholesterol and is helping you to control your weight, diabetes, and hypertension. Aerobic exercises, the ones which use oxygen to provide the energy for adequate muscle work benefit your heart and lungs.

Other things that you should have in mind are: to stop smoking (it is never enough attention to this problem. While cigarettes have a bad effect on blood vessels, heart, and lungs, they also lower the HDL production), lower overly consumption of alcoholic beverages, regulate your stress level as much as you are able to, and consider some health supplements.

Health supplements

Artichoke supplement

Artichoke is used in the treatment of digestion disorders, stagnation of bile, increased cholesterol and urea levels. It is used in liver diseases and atherosclerosis. The beneficial effects can be seen after 2 – 8 weeks. Artichoke lowers the total cholesterol and LDL thus reducing the LDL: HDL ratio after 6 – 12 weeks.

Ramson (Allium ursinum)

Ramson lowers the blood pressure, improves the full blood count, lowers the cholesterol, triglycerides, and glucose. It is a powerful antioxidant and generally makes the immune system stronger.

Omega-3 fatty acids

Omega-3 fatty acids can reduce the triglycerides in the blood, and lower the risk of death caused by heart diseases. They increase HDL and lower the chance for stroke and cancer.

Vitamin B3

While used as medicine in larger concentration, you can use it as a supplement in lower doses. It lowers the level of triglycerides and increases the level of HDL. Insufficiency of B3 can be caused by chronic alcoholism.

Hibiscus

Hibiscus lowers LDL and has flavonoids, which stop the atherosclerotic plaque in blood vessels. It has an antioxidant effect, decelerates the aging process, and prolongs life.

Pharmacological therapy

If non-pharmacological measures don’t help you, your doctor may prescribe you one of these:

Statins

Most important medicines in reducing cholesterol are statins. They are inhibitors of HMG – COA reductase enzyme which is an important factor in the liver’s cholesterol synthesis. Since the cholesterol is an important substance for the living organism, the liver sends it to other tissues, therefore the receptors for LDL are being expressed on hepatocytes, and thus bind LDL from the blood. With this method, statins can lower LDL for about 40%. Statins can also lower the triglyceride levels, but this effect is not as good as it is in fibrates. Since the cholesterol is made during the night, these medicines are always to be used once per day in the evening.

Studies have shown that statins are beneficial to people with high risk for cardiovascular diseases unrelated to their effect on LDL. They are given in the chronic treatment of stable and unstable angina pectoris as well as after the cardiac arrest. Statins lower the CRP (C-reactive protein found in blood plasma whose levels is risen during the inflammation), they slower the hyperplasia of blood vessels (blood vessel enlargement), they stabilize the atherosclerotic plaque, while improving the endothelial function.

Nicotinic acid

Nicotinic acid, known as niacin or vitamin B3 also has an effect on cholesterol levels in the blood. Niacin’s effect on LDL and triglycerides is weak, but it significantly increases the production of HDL (theoretically by 40%). It inhibits HDL’s catabolism and secretion of VLDL from the liver. The medicine dose for niacin is much higher than its vitamin dose, so it can cause skin redness.

Bile acid sequestrants

Bile acid sequestrants are resins used to bind bile acids and eliminate them with the feces. In this way, they decrease the cholesterol levels, but on the other hand the emulsifiers important for absorbing other fat-soluble substances also. Because the bile acids are being excreted, hepatocytes stimulate the liver to take more cholesterol from food into itself, so LDL receptors are being expressed, and LDL level drops.

Fibrates

These are the medicines that are used for regulating the triglyceride levels. They lower VLDL in circulation, thus manage the triglyceride levels, but their effect on LDL and HDL is low. Fibrates work as PPAR α agonists which stimulate activation of genes responsible for the synthesis of lipoprotein lipase which breaks up the triglycerides. They decrease expression of genes responsible for the synthesis of apoC III which inhibits the hydrolysis and the clearance of VLDL.