Cholesterol in serum and its fractions - general information, analytical methods, interferences, risk limits, interpretation of results
Cholesterol is present in all animal cells. cholesterol is the most common type of steroid in the body. Cholesterol is an essential nutrient necessary for many functions, including repairing cell membranes. Cholesterol is also necessary to the normal permeability and function of cell membranes. It is essential to the formation hormones (Oestrogens, Androgens) Bile acids, Manufacturing vitamin D.
Most of the cholesterol that the body needs are produced by the liver. The remaining, approximately 20 percent of the total, is derived from food. Total cholesterol as a laboratory parameter comprises all the cholesterol in blood found in various lipoproteins. The body uses low density lipoprotein (LDL) and high-density lipoprotein (HDL) to transport cholesterol through the blood.
Analytical method: Direct enzymatic concentrations measurements for LDL, HDL, and cholesterol
Interferences: Factors that affect blood cholesterol levels include age, sex, body weight, diet, alcohol and tobacco use, exercise, genetic factors, family history, medications, menopausal status, the use of hormone replacement therapy, and chronic disorders such as hypothyroidism, obstructive liver disease, pancreatic disease (including diabetes), and kidney disease.
Indication for analysis: For evaluation of the risk of developing cardiovascular disease and atherosclerosis. As a rule, the higher the LDL cholesterol level, the greater the risk to health.
Preparation of the patient and specimen: Current standards recommend that testing be done in fasting condition. For 9 to 12 hours before the test, only water is permitted. In addition, alcohol should not be consumed for 24 hours just before the test. Sitting down for at least five minutes before the blood is taken.
Recommended Ranges:
- Total cholesterol (TC) - 5.2 mmol/l or less.
- LDL after an overnight fast: 3.4 mmol/l or less.
- HDL 1.2 mmol/l or more.
- TC/HDL ratio: 4.5 or less
Interpretation of results:
Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease. It is closely related to the terms "hyperlipidemia" (elevated levels of lipids in the blood) and "hyperlipoproteinemia" (elevated levels of lipoproteins in the blood). When cholesterol levels rise in the blood, they can have dangerous consequences, depending on the type of cholesterol. In many individuals, an elevated blood cholesterol level constitutes an increased risk of developing coronary artery disease.
A hereditary form of high LDL is familial hypercholesterolemia (FH). Increased LDL is termed hyperlipoproteinemia type II.