Test Code 222
Test Details
Direct Low Density Lipoprotein Cholesterol (LDL-C)
LDL-C is a measure of the amount of cholesterol in the atherogenic low-density lipoproteins. The direct measurement of LDL-C is not affected by non-fasting state. Values are somewhat higher than calculated LDL-C.
Methodology
Enzymatic colorimetric.
Patient Preparation
8-12 hour fast prior to collection. Patient may drink water only. (If ordered as part of a stand-alone test, fasting is not required.)
Preferred Specimen
1.0 mL serum (0.5 mL minimum) collected in serum separator tube (SST/Tiger Top)
Alternate Specimen
- 1.0 mL EDTA plasma (0.5 mL minimum) collected in plasma separator tube (Pearl Top)
- Dried Blood collected on an AdvanceDx 100 card
Transport Temperature
Refrigerated (ship on frozen cold packs)
Stability
Refrigerated: 7 days
Lab Values
Direct Low Density Lipoprotein Cholesterol (LDL-C)
| Age | Optimal | Borderline | Increased Risk |
| ≤18 yrs | <100 mg/dL | 100 – 129 mg/dL | >129 mg/dL |
| >18 yrs with CVD | <70 mg/dL | 70 – 100 mg/dL | >100 mg/dL |
| >18 yrs without CVD | <100 mg/dL | 100 – 160 mg/dL | >160 mg/dL |
Clinical Significance
Direct Low Density Lipoprotein Cholesterol (LDL-C)
Elevated LDL-C is a primary, independent risk factor for CVD per NCEP-ATP III.1
References:
- Goff DC Jr, Lloyd-Jones DM, Bennett G, et al. 2013 ACC/AHA Guideline on the Assessment of Cardiovascular Risk: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2014;129(25 Suppl 2):S49-73.
Treatment Options
Direct Low Density Lipoprotein Cholesterol (LDL-C)
- Lifestyle modification
- Statins
- Fibrates
- Soluble Fiber
- Niacin
- Cholesterol absorption inhibitor
- Bile acid sequestrants
- PCSK9 inhibitor (if indicated for a very high LDL-C)
