Fatty Acids, Free (Nonester)
Also known as: Free Fatty Acids, Nonesterified Free Fatty Acids
Use
Knowledge of the level of nonesterified fatty acids (NEFA) in blood plasma can be helpful in the diagnosis and management of certain diseases and disorders of metabolism and in the evaluation of prospective causes of hyperlipoproteinemia. A disorder of disease that causes excessive release of a lipoactive hormone (epinephrine, ACTH, GH, etc) can induce an elevation of blood level of fatty acids. A sustained release of fatty acids from adipose cells in excess of energy needs can contribute to the development of secondary hyperlipoproteinemia.
Special Instructions
Sample should be collected in the early morning after a 12-hour fast. Blood for the NEFA procedure should be collected following this fast, as food ingestion strongly influences circulating nonesterified fatty acid levels. If fasting is not properly adhered to, NEFA levels will be elevated and incomparable to normal fasting ranges.
Limitations
The NEFA level in serum may increase while remaining at room temperature due to enzymatic action. Heparin must not be used, as it stimulates lipoprotein lipase activity, altering NEFA levels. Blood from patients on heparin therapy or collected in heparinized containers is unsuitable for this test.
Methodology
Automated Analyzer
Biomarkers
LOINC Codes
- 15066-4
- 15066-4
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.2 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
After clotting, separate serum and freeze immediately following centrifugation. Serum is the specimen of choice. Transfer the specimen to a plastic transport tube before freezing.
Patient Preparation
Sample should be collected in the early morning after a 12-hour fast.
Storage Instructions
Freeze. The NEFA level will increase in serum at room temperature.
Causes for Rejection
Heparin plasma received; specimen not frozen. Blood from patients on heparin therapy is unsuitable.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 hours |
| Refrigerated | 1 day |
| Frozen | 105 days |