Low-Density Lipoprotein Cholesterol (Direct)

Test ID:

703018

CPT code:

83721

Synonyms:

Direct LDL
Direct LDLC
LDL Cholesterol, Direct
LDLC, Direct

Clinical Use:

For the direct determination of LDL cholesterol in nonfasting patients or in patients whose fasting triglycerides are >400 mg/dL, where the estimation of LDL by calculation may not be possible or may lead to inaccuracies. LDL cholesterol measurement, in conjunction with other lipid measurements, has been shown to be useful in assessing the risk of coronary heart disease (CHD). The National Cholesterol Education Program (NCEP)1 has stated that LDL cholesterol should be the “key index” in determination of CHD risk. Laboratory estimation of LDL cholesterol is most commonly determined by the use of formulas, such as the Friedewald formula.2 Use of this formula is limited to fasting samples with triglycerides <400 mg/dL. Triglyceride values between 250−400 mg/dL may also be associated with errors in LDL cholesterol estimation by calculation which, in turn, can lead to misclassification of the patient in regard to the NCEP guidelines.

Specimen Type:

Serum (preferred) or plasma

Requested Volume:

0.5 mL

Minimum Volume:

0.4 mL

Container Type:

Red-top tube, gel-barrier tube, lavender-top (EDTA) tube, or green-top (heparin) tube

Patient Preparation:

Patients are not required to fast prior to blood collection. Nonfasting and fasting samples can be used. Nonfasting results are slightly lower than fasting results.