Cholesterol, HDL
fS-Kol-HDL KL 2097
Part study of the Lipid profile test package
The HDL particle plays a crucial role in the reverse transport of cholesterol, responsible for transporting cholesterol from peripheral tissues back to the liver. This process involves the formation of HDL particles primarily around the apoA protein secreted by the liver (70%) and the small intestine (30%). These HDL particles take on a plate-like pre-β-HDL structure, comprising phospholipids, cholesterol, and apoA-I protein. In the bloodstream, pre-β-HDL particles collect free cholesterol from cell membranes with the help of transport proteins. These cholesterol molecules are either produced by the tissues themselves or received via an LDL particle.
The pre-β-HDL particle, now filled with cholesterol esters, undergoes a transformation into a spherical shape. Carried by the newly generated HDL particles, the cholesterol is then transported to the liver. This transfer occurs either through the joint action of hepatic lipase and the HDL receptor or via the LDL receptor, where recognition occurs through the apoE protein present in some HDL particles.
HDL-cholesterol measurement is an essential part of the diagnostic tests for dyslipidemia, which pertains to abnormal fat values in the blood. Other tests include fS-Kol, fS-Kol-LDL, and fS-Trigly. To accurately diagnose dyslipidemia, at least two samples must be taken on different days, and the levels of total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides are determined.
Indications
Monitoring the treatment of hypercholesterolemia. Assessment of risk for coronary artery disease.
Sample
1 mL of fasting serum, minimum 0.5 mL.
Storage and delivery
The sample can be refrigerated for up to a week, but for longer storage, it should be kept frozen. Delivery at room temperature, if it arrives within 24 hours.
Method
Photometric, enzymatic. Accredited method.
Turnaround time
1 – 2 weekdays
Reference ranges
recommended value over 1.0 mmol/L
The target value is determined according to the Dyslipidemiat Käypä hoito (Current Care Guidelines for Dyslipidemias) recommendation published on October 27, 2020, by the Finnish Medical Society Duodecim and the Finnish Association of Internal Medicine.
Interpretation of results
An individual’s HDL-cholesterol level is primarily influenced by genetic factors inherited from their parents, while nutrition plays a lesser role. In women, before menopause, HDL cholesterol levels are generally higher compared to men, attributed to the presence of the female sex hormone estrogen.
Regarding external factors, engaging in endurance-level exercise and quitting smoking have a positive impact on HDL-cholesterol levels. Additionally, moderate alcohol consumption can also lead to a slight increase in HDL concentration.
On the other hand, a diet rich in carbohydrates and low in fat (less than 20% of energy), particularly when lacking sufficient fiber content, can result in reduced serum HDL-cholesterol levels. Moreover, low HDL cholesterol values are often observed in individuals with waist obesity and insulin resistance.
Literature:
Dyslipidemiat, Käypä hoito-suositus, 14.12.2022. Suomalaisen Lääkäriseuran Duodecimin ja Suomen Sisätautilääkärien Yhdistys ry:n asettama työryhmä
Ravitsemustiede, Duodecim 2021 (toim. M. Mutanen, H. Niinikoski, U. Schwab, M. Uusitupa)
Inquiries
martin.tornudd@milalab.fi
Last update 8.8.2023
