Dyslipidemia

Dyslipidemias are known as alterations in lipid metabolism.

Hyperlipidemia is the increase in blood of cholesterol, triglycerides or both at the same time, above the values ​​considered normal.

Hyperlipidemia leads to an elevation of low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL); and to a lesser extent, chylomicrons, intermediate density lipoproteins (IDL) or high density lipoproteins (HDL).

Statistical and clinical criteria such as cardiovascular risk are used to define normal values. The risk of dying from ischemic heart disease is known to increase as cholesterol levels rise.

What are blood lipids?

Blood fats, which are also called lipids, are the main reserve substances in the body, therefore they serve to provide us with energy. Other of its functions is to constitute an integral part of the cell membranes. A part of the fats is produced from the digestion of food and another part is made by our own body.

These fats are transported by the blood to different organs and tissues to be used as an energy source. When their use is not necessary immediately, they are stored. If lipids are high, we can act on them through diet or medications. If we do not act, we run the risk of suffering from cardiovascular diseases. This risk increases when other factors are also associated such as: hypertension, tobacco, diabetes , obesity, sedentary lifestyle, etc.

What are the most important lipids?

The lipids that we can find in human serum are classified into four large groups:

• Free fatty acids.
• Triglycerides.
• Cholesterol.
• Phospholipids.

The first three belong to simple lipids and phospholipids to complex lipids. Of all of them, the best known are cholesterol and triglycerides. Cholesterol is produced for the most part by the body itself. Its level in the blood also depends on the composition of the food eaten, that is, on the kind of dietary fat and its cholesterol content.

Example: egg and butter are high in cholesterol. Triglycerides are also ingested with food (butter, cold cuts, dairy products, etc.), although the body can transform other components of food into triglycerides, especially carbohydrates (sugar). This transformation takes place in the liver and adipose (fat) tissue. They are the body’s main form of energy reserve.

Why does dyslipidemia occur?

The alterations of the lipids in our organism are divided according to the causes that produce it in:
Idiopathic hyperlipemias: of unknown origin.

• Primary hyperlipemias: they are due to genetic disorders. Among them we find:
• Polygenic familial hypercholesterolemia.
• Monogenic familial hypercholesterolemia.
• Combined familial hyperlipemia.
• Familial hypertriglyceridemia.
• Familial dysbetalipoproteinemia.
• Hyperkylomicronemia (familial lipoprotein lipase deficiency).
• Hyperalphalipoproteinemia.
• Familial hyperlipidemia.

Secondary hyperlipemias: they are due to the following factors:

• Mellitus diabetes.
• Drugs and toxins: excessive alcohol consumption, oral contraceptives, diuretics (thiazides), beta-blockers, corticosteroids …
• Endocrinological diseases and metabolic disorders: Cushing’s syndrome, obesity, hyperuricemia, hypothyroidism …
• Chronic renal insufficiency.
• Liver failure.

Symptoms of dyslipidemia

The arteriosclerosis is a multifactorial process in which alterations in lipid metabolism have an essential role. Dyslipidemias are an independent risk factor for the development of cardiovascular disease, especially ischemic heart disease:

• There are multiple studies that have shown a close relationship between elevated levels of total cholesterol and LDL, and the appearance of ischemic heart disease and coronary mortality
• Total cholesterol is one of the main risk factors for ischemic heart disease.
• The effect of the sum of risk factors in patients with dyslipidaemia is multiplicative.
• Total cholesterol levels can be modified with changes in diet.
• Measures that lower plasma cholesterol protect against coronary disease.

There are different classifications, but from a practical point of view, the most interesting is the simplified classification which is based solely on plasma cholesterol and triglyceride concentrations.

• Hypercholesterolemia: total cholesterol greater than 200 mg / dl. and triglycerides below 200 mg / dI.
• Hypertriglyceridemia: total cholesterol below 200 mg / dl. and triglycerides above 200 mg / dl.
• Mixed hyperlipidaemia: total cholesterol above 200 mg / dl. and triglycerides above 200 mg / dI.

Polygenic familial hypercholesterolemia

It’s the most frequent form. It affects approximately 5% of the population. It is a consequence of the interaction of genetic and environmental factors (especially dietary). It is generally asymptomatic until adulthood. It does not usually present cutaneous manifestations. It presents an increase in total cholesterol between 250 and 300 mg./dl. Above all, LDL lipoproteins are elevated. Triglycerides are normal. It implies an increased risk of cardiovascular and ischemic heart disease after the age of 50.

Monogenic familial hypercholesterolemia

It has very high levels of total cholesterol and LDL-cholesterol, even above 600 mg / dl. Triglycerides are not usually elevated. High risk of ischemic heart disease: early coronary atheromatosis (before the age of 10 years) that frequently causes death before the age of 30. It occurs with cutaneous manifestations: tendon xanthomas, xanthelasmas. Corneal arch may also appear.

Combined familial hyperlipidemia

Involvement is found in 50% of first-degree relatives. It is usually detected in adulthood (25-30 years). It causes high levels of total cholesterol, triglycerides, or both. It has a high risk of coronary involvement.

Familial hypertriglyceridaemia

Moderate increase in triglycerides. VLDL lipoproteins are greatly increased. Low levels of LDL-cholesterol and HDL-cholesterol. It is usually asymptomatic, although it can present symptoms when associated with risk factors such as alcohol consumption, hypothyroidism or diabetes, causing a hyperchylomicronemic syndrome that consists of: abdominal pain, hepatosplenomegaly (enlargement of the liver and spleen), xanthomas, lipemia retinalis. It does not appear to be associated with an increased risk of ischemic heart disease.

Familial dysbetalipoproteinemia

Increase in total cholesterol and triglycerides. It is not usually detected before the age of 20 and is clinically characterized by the appearance of flat xanthomas and striated palmar xanthomas on the palms of the hands. It also presents with tuberous xanthomas on the elbows and knees and xanthelasmas. High risk of atheromatous vascular disease: early ischemic heart disease, cerebrovascular disease and lower limb arteriopathy.

Hyperkylomicronemia or familial lipoprotein lipase deficiency

It is a very rare form. It is characterized by increased triglycerides and chylomicrons. It presents with eruptive xanthomas and enlargement of the liver and spleen. High risk of pancreatitis.

Hyperalphalipoproteinemia

It is characterized by HDL-cholesterol levels between 100-200 mg / dl. It is associated with a low risk of coronary heart disease and does not require any treatment.

How is it diagnosed?

A determination of total cholesterol is recommended before the age of 35 years in men and 45 years in women, and then every 5-6 years until age 65. In people over 65 years it is recommended to determine total cholesterol at least once. The determination of total cholesterol is also recommended in those people with risk factors, regardless of their age. The risk factors to consider are, among others:

1. Family history of: coronary heart disease, sudden death or hyperlipemia.
2. Personal history of: arterial hypertension , diabetes mellitus, tobacco abuse and obesity. Regarding triglycerides, there are no specific recommendations for their systematic determination. The elevated value of HDL-cholesterol above 60 mg / dl, is considered a protective effect.

Treatment for dyslipidemia

DIET low in saturated fat.

• Avoid being overweight.
• Avoid foods that contain a lot of cholesterol, such as meats and sausages rich in fat, offal, as well as shellfish, crabs, prawns, etc.
• Avoid fatty dairy products, such as butter, cream, high-fat cheeses, etc.
• Use vegetable oils in the preparation of meals, avoiding fats and oils of animal origin. You should also do without mayonnaise and butter.
• Excess carbohydrates are transformed into fat, therefore, sweets, jam, cakes, ice cream, candies, chocolates, etc. should be avoided.
• Get regular exercise.
• If your doctor has prescribed any medication, you should take it regularly.

How to avoid it?

Hygienic-dietary measures

They are all those measures aimed at modifying the lifestyle.

Its objective is to achieve healthy habits with a positive influence on plasma lipid levels as well as on other cardiovascular risk factors:

• Smoking cessation.
• Decrease in alcohol consumption and in certain cases suppress it.
• Correction of obesity and reduction of overweight.