LDL
About Test
The Low-Density Lipoprotein (LDL) test measures the level of LDL cholesterol, commonly known as "bad" cholesterol, in the blood. LDL cholesterol is responsible for transporting cholesterol from the liver to the cells. However, high levels of LDL can lead to the accumulation of cholesterol in the walls of arteries, forming plaque and increasing the risk of cardiovascular diseases such as heart attacks, strokes, and atherosclerosis.
The LDL test is an important component of a lipid profile and helps assess an individual’s risk of heart disease. Elevated LDL levels are often associated with other risk factors like high blood pressure, diabetes, and a family history of cardiovascular conditions. Managing LDL levels through lifestyle changes such as diet and exercise, or with medications like statins, is crucial for reducing cardiovascular risk and improving overall heart health.
Regular monitoring of LDL cholesterol levels allows healthcare providers to evaluate the effectiveness of treatment strategies, make necessary adjustments, and ensure that patients maintain healthy cholesterol levels for long-term cardiovascular health.
Sample Requirements
Gold SST Tube
Stability
Serum: 7 days 2-8°C, 12 months -20°C
Turnaround Time
4 hours
Assay Interferences
Interferences
Lipemia: No significant interference up to an L index of 1000. There is poor correlation between the L index (corresponds to turbidity) and triglycerides concentration.
Icterus: No significant interference up to an I index of 60 for conjugated and unconjugated bilirubin (approximate conjugated and unconjugated bilirubin concentration: 1026 µmol/L or 60 mg/dL).
Haemolysis: No significant interference up to an H index of 1000 (approximate hemoglobin concentration: 621 µmol/L or 1000 mg/dL).
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Other: No significant interference from HDL‑C (≤ 3.03 mmol/L or ≤ 117 mg/dL), VLDL‑C (≤ 3.63 mmol/L or ≤ 140 mg/dL), or chylomicrons (≤ 22.6 mmol/L or ≤ 2000 mg/dL triglycerides).
Nicotinic acid (Niacin), statins (Simvastatin) and fibrates (Clofibrate) tested at therapeutic concentration ranges did not interfere.
Acetaminophen intoxications are frequently treated with N‑acetylcysteine. N‑acetylcysteine at the therapeutic concentration when used as an antidote and the acetaminophen metabolite N‑acetyl-p‑benzoquinone imine (NAPQI) independently may cause falsely low LDL‑C results. Venipuncture should be performed prior to the administration of metamizole. Venipuncture immediately after or during the administration of metamizole may lead to falsely low results.
Abnormal liver function affects lipid metabolism; consequently HDL and LDL results are of limited diagnostic value. In some patients with abnormal liver function, the LDL‑cholesterol result is significantly negatively biased versus beta quantification results. EDTA plasma may cause decreased values compared to serum.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Reference Range (mmol/L):
Healthy: < 3.0
Critical Value:
Not applicable