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HelpTest ID NEFA Free Fatty Acids, Total, Serum
Useful For
Evaluation of metabolic status of persons with endocrinopathies
Detection of pheochromocytoma and of glucagon-, thyrotropin-, and adrenocorticotropin-secreting tumors
Monitoring of control of diabetes mellitus (serum-free glycerol is a very useful companion test in assessing diabetes and may be ordered by special request from Mayo Medical Laboratories). The correlation with insulin resistance and downstream cardiovascular risk may be a useful treatment aid in some patients.
Method Name
Enzymatic Colorimetric
Reporting Name
Free Fatty Acids, Total, SSpecimen Type
SerumCollection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Fasting-overnight (12-14 hours).
2. Patient must not consume any alcohol for 24 hours before the specimen is drawn.
3. Spin down within 45 minutes of draw.
4. Immediately freeze specimen.
Forms: If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen http://www.mayomedicallaboratories.com/it-mmfiles/cardiovascular-request-form.pdf).
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Frozen | |
Clinical Information
All but 2% to 5% of serum fatty acids are esterified. The "nonesterified" or "free" fatty acids are protein-bound. The amount of free fatty acids in the serum rises after a fatty meal, but tends to fall after ordinary meals. Levels are elevated in obesity.
Lipoactive hormones such as epinephrine, norepinephrine, glucagon, thyrotropin, and adrenocorticotropin release free fatty acids. Tumors producing such hormones cause release of excessive quantities of free fatty acids. Serum free fatty acids are also increased in patients with uncontrolled type 2 diabetes mellitus and are an indicator of insulin resistance. Free fatty acids are associated with increased reactive oxygen species (ROS), probably mediated by free fatty acid activation of NADPH oxidase. The link between increased ROS and decreased nitric oxide production is a contributor to endothelial dysfunction.
Reference Values
≥16 years: 0.00-0.72 mmol/L
Reference values have not been established for patients who are <16 years of age.
Cautions
Patient should fast for 12 to 14 hours; however, in prolonged fasting or starvation, free fatty acid levels rise as much as 3-fold.
Patient should abstain from alcohol for at least 24 hours.
In order to eliminate the generation of free fatty acids from triglycerides by serum lipases (causing erroneous elevations), serum should be frozen soon after it is drawn and shipped frozen.
Day(s) Performed
Monday through Friday; 7 a.m.-5 p.m.
Report Available
1 day (not reported on Saturday or Sunday)Performing Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82725