LDL cholesterol

It is a blood test for determining the level of LDL cholesterol using the direct method.

It is used to determine the concentration level of LDL cholesterol fraction (low-density lipoproteins), or the so-called “bad” cholesterol. Elevated LDL cholesterol levels are associated with the risk of cardiovascular diseases.

The causes of elevated LDL concentration levels include:

• improper lifestyle (poor diet, lack of physical activity),
• secondary dyslipidaemia.

Decreased LDL cholesterol levels may be caused by:

• hyperthyroidism,
• cirrhosis and liver damage,
• septicaemia and cachexia.

What is bad cholesterol and when should it be tested?

LDL cholesterol is one of the fractions of total cholesterol. Its blood concentration levels are primarily determined to specify the risk of developing ischaemic heart disease. Healthy individuals are advised to have their cholesterol levels analysed on a preventive basis. The frequency of the test in individuals from the risk group is determined by the physician. Elevated levels of LDL cholesterol are observed, amongst others, in individuals who are obese, have bad eating habits, smoke tobacco and are chronically ill.

What is LDL cholesterol?

LDL cholesterol transports cholesterol in the blood. Its excess is deposited in the walls of blood vessels, thereby contributing to atherosclerosis and ischaemic heart disease, and hence the name “bad” cholesterol.

Cholesterol is an essential component of cellular membranes and fatty acids, and without its adequate concentration in the body, it is impossible for the nervous and endocrine systems to function properly. What is dangerous, however, is the excess of cholesterol in the body and the disproportion between the “good” and the “bad” cholesterols.

Risk factors for cardiovascular diseases

High concentration levels of LDL cholesterol represent a risk for the vascular system and the heart. It represents a risk factor for myocardial infarction (MI), stroke and ischaemic heart disease. Assessing the levels of total cholesterol and its particular fractions – LDL and HDL – is part of the prevention measures against circulatory diseases, and – in the case of chronically treated patients – a method for monitoring the progress of treatment, including the diet-based treatment.

It is considered that improper concentration levels of LDL cholesterol in the blood are mainly caused by a poorly-balanced diet rich in animals fats and processed food products. Chronic diseases are not insignificant either – obesity, diabetes and other factors related to lifestyle – inadequate levels of physical activity and smoking cigarettes.

How often should LDL cholesterol be tested?

As a prevention, healthy individuals are indicated to have their cholesterol concentration and complete lipid profile tested once every 3–5 years when aged 25 years and more, and every 2 years when aged 50 years and more), as well as in patients at risk of developing circulatory diseases. In the event of chronic treatment or in patients at a higher risk of developing atherosclerosis and circulatory diseases, it is the physician that determines the frequency of the tests.

What does the LDL cholesterol test look like?

The concentration level of this cholesterol fraction is usually assessed upon analysis of a blood sample collected from the patient.

Patients should have their blood collected while being on an empty stomach (10–12 hours after your last meal). The day before, it is necessary to refrain from consuming fat and heavy food. Patients must refrain from drinking alcohol a few days (2-3) before the test. In certain cases, it is not necessary to be on an empty stomach for the test. However, it is the physician who decides how you should prepare for the test, so it is necessary to follow his/her instructions.

Patients are advised to appear at the blood collection point earlier to be able to sit down and rest for 10–15 minutes before sample collection.

The process of blood sampling lasts a few dozen seconds. Upon disinfection of the injection site and application of a tourniquet, a blood sample is collected from the ulnar vein. Directly after removing the needle, the blood collection site should be compressed for a few minutes using a sterile gauze pad to prevent bruising of the injection site.

• The blood collection itself lasts from several to a few dozen seconds.
• The procedures related to blood sample collection, including skin disinfection, tourniquet application and compression at the injection site after needle removal, last a few minutes.
• There are no contraindications to this test.

1-2 weeks before the test

• Keep a normal diet and constant body weight, and lead a habitual lifestyle.

A few days before the test

• Do not drink alcohol for 2–3 days before the test.
• Refrain from drinking coffee and tea for at least 12 hours before blood collection.
• Where possible, eliminate the sources of stress.

On the day of the test

• Stay on an empty stomach – which means you should refrain from consuming any meals for about 12 hours before the test.
• Drink some water in the morning, but not more than a glass.
• The blood sample for the test should be collected in the morning hours.
• Unless otherwise directed by the physician, blood should be sampled before intake of morning medications.
• Relax in a sitting position for 10-15 minutes directly before your blood is collected.

In the event of improper preparation for the blood test, the results will not be fully reliable.

Acceptable LDL cholesterol levels for adults

The test results should not be interpreted on your own. It is the physician that can assess whether the results and treatment progress are correct, based on the other parameters determined in the test, information about the patient’s health and his/her medical and treatment histories.

The overall acceptable level of LDL cholesterol for healthy individuals is 100 mg/dl. In patients with diabetes and ischaemic heart disease, the purpose is to achieve lower values.

Individuals with abnormal concentration levels of LDL cholesterol are, in the first place, recommended to change their lifestyle and diet. It is important to minimise the consumption of animal fats and highly processed foodstuff. Tobacco users should receive support to help them gradually cut down on the number of cigarettes smoked and eventually quit smoking at all. Patients are recommended to get involved in daily physical activity adapted to their preferences and health condition – they are recommended to go for a walk, a walk/run, ride a bike, swim, and dance.

Chronically ill patients, for whom it is not enough to change the lifestyle, are put on pharmacological treatment.

• Test results are available within 3 working days.
• It is possible to collect them at the reception desk of a selected centre.
• The results can be accessed online. For this to be possible, it is necessary to collect a password at the reception desk of a selected centre.