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HelpTest Code LABOMEGACK OmegaCheck
Additional Codes
| Test Name in EPIC | EPIC Test Code | Quest Test ID |
|---|---|---|
| OmegaCheck | LABOMEGACK | 92701 |
Useful For/Utility
Clinical use
Determine fatty acid-associated risk for cardiovascular events
Clinical background
Diets rich in omega-3 polyunsaturated fatty acids (PUFAs) are beneficial for heart health and reduce the risk of cardiovascular disease (CVD) and events (eg, myocardial infarction [MI]).1 Because of their beneficial effects, the United States Food and Drug Administration has approved the use of 2 prescription omega-3 fatty acid products for patients with very high triglyceride levels (≥ 500 mg/dL).2,3
The 3 major omega-3 PUFAs are eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA). Another omega-3 PUFA, docosapentaenoic acid (DPA), is an intermediate metabolite formed during the interconversion of EPA and DHA. Fish oil and fatty fish such as salmon, mackerel, herring, and tuna are the primary dietary sources of EPA and DHA. ALA is found in plant-based foods such as green leafy vegetables, beans, and vegetable oils, and after ingestion it is metabolized to EPA.1,4
Because of interindividual differences in genetics and metabolism, dietary intake of omega-3 PUFAs and/or supplements does not strongly correlate with concentrations in the body.4-6 Individuals with the same dietary intake can have different concentrations of omega-3 PUFAs.4-6 To assess whether an individual's omega-3 PUFA levels are sufficient to achieve a reduction in CVD risk, blood testing is needed.5,6 Measuring the sum of EPA and DHA in red blood cells is 1 method used to determine an individual's omega-3 PUFA levels.7 Combined levels ≥8% are associated with reduced CVD risk.1,7,8
The OmegaCheck® test (test code 92701) offered by Quest Diagnostics and Cleveland HeartLab is another method for measuring omega-3 PUFAs and assessing the risk of CVD. The OmegaCheck test uses the sum of EPA, DHA, and DPA in whole blood expressed as a percentage of total fatty acids.9 OmegaCheck and the sum of EPA and DHA in red blood cells (also called the Omega-3 index) values are highly correlated (r=0.91)8 and are used as indicators for sudden cardiac death9 and nonfatal cardiovascular events.
Methodology
LC/MS/MS measurement of EPA, DHA, DPA, LA, and AA, which are reported as a percentage of total fatty acids (PLFAs); total PLFA measurement includes the 19 highest-concentration fatty acids (C14 through C22) present in plasma phospholipids.
Calculations
OmegaCheck = [(EPA + DPA + DHA) ÷ total PLFA] x 100
Omega-6/omega-3 = sum of 6 omega-6 fatty acids ÷ sum of 3 omega-3 fatty acids
AA/EPA = % AA ÷ % EPA
Analytical sensitivity
EPA: 0.03%
DHA: 0.03%
DPA: 0.02%
Specimen Requirements
Preferred Specimen(s)
0.5 mL whole blood collected in an EDTA (lavender-top) tube
Minimum Volume
0.1 mL
Collection Instructions
1. Collect and label sample according to standard protocols.
2. Gently invert tube 8-10 times immediately after draw. DO NOT SHAKE.
3. Do not centrifuge.
4. Store and transport refrigerated.
Transport Container
EDTA (lavender-top) tube
Specimen Transport Temperature
Refrigerated (cold packs)
Performing Laboratory
Quest Diagnoistics
Test Classification and CPT Coding
82542
Reference Values
The CVD risks associated with OmegaCheck values are shown in the Table. Thresholds were established by stratifying data of the studied population into quartiles. Previous population-based studies have shown a dose-dependent decrease in CVD risk with increasing levels of omega-3 PUFAs. Relative to individuals in the highest quartile, individuals in the lowest quartile are at highest risk and those in the second and third quartiles (combined in the Table) are at moderate risk.8,10
Table. Interpretation of OmegaCheck Values
OmegaCheck value, % by weight
Cardiovascular disease risk level
≥5.5
Lowa
3.8-5.4
Moderate
≤3.7
High
a Relative to those with lower OmegaCheck values.
Consumption of foods high in omega-3 fatty acids (EPA and DHA), dietary supplements containing omega-3 fatty acids, and prescription omega-3 fatty acids can increase the OmegaCheck value, which is associated with decreased CVD risk (Table).
A high omega-6/omega-3 ratio is associated with a higher risk of major coronary events but should be interpreted with caution because it does not differentiate fatty acids that have different physiologic properties (eg, effect on platelet function and lowering triglycerides).11
A higher AA/EPA ratio is associated with higher risk for major coronary events (sudden cardiac death, fatal or nonfatal myocardial infarction, unstable angina pectoris with myocardial ischemia, or the need for revascularization procedures).12
References
Elagizi A, Lavie CJ, O'Keefe E, et al, An update on omega-3 polyunsaturated fatty acids and cardiovascular health. Nutrients. 2021;13(1):204. doi:10.3390/nu13010204
Lovaza® (omega-3-acid ethyl esters). Prescribing information. GlaxoSmithKline; 2008. Accessed June 6, 2022. https://www.accessdata.fda.gov/drugsatfda_docs/label/2009/021654s023lbl.pdf
Vascepa®. Prescribing information. Amarin Pharma Inc; 2021. Accessed June 6, 2022. https://amarincorp.com/docs/Vascepa-PI.pdf
Davinelli S, Intrieri M, Corbi G, et al. Metabolic indices of polyunsaturated fatty acids: current evidence, research controversies, and clinical utility. Crit Rev Food Sci Nutr. 2021;61(2):259-274. doi:10.1080/10408398.2020.1724871.
Harris WS, Tintle NL, Imamura F, et al. Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies. Nat Commun. 2021;12(1):2329. doi:10.1038/s41467-021-22370-2
Flock MR, Skulas-Ray AC, Harris WS, et al. Determinants of erythrocyte omega-3 fatty acid content in response to fish oil supplementation: a dose-response randomized controlled trial. J Am Heart Assoc. 2013;2(6):e000513. doi:10.1161/JAHA.113.000513
McDonnell SL, French CB, Baggerly CA, et al. Cross-sectional study of the combined associations of dietary and supplemental eicosapentaenoic acid + docosahexaenoic acid on Omega-3 Index. Nutr Res. 2019;71:43-55. doi:10.1016/j.nutres.2019.09.001.
Harris WS, von Schacky C. The Omega-3 Index: a new risk factor for death from coronary heart disease? Prev Med. 2004;39(1):212-220. doi:10.1016/j.ypmed.2004.02.030
Albert CM, Campos H, Stampfer MJ, et al. Blood levels of long-chain n-3 fatty acids and the risk of sudden death. N Engl J Med. 2002;346(15):1113-1118. doi:10.1056/NEJMoa012918
Siscovick DS, Raghunathan TE, King I, et al. Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. JAMA. 1995;274(17):1363-1367. doi:10.1001/jama.1995.03530170043030
Harris WS. The Omega-6:Omega-3 ratio: A critical appraisal and possible successor. Prostaglandins Leukot Essent Fatty Acids. 2018;132:34-40. doi:10.1016/j.plefa.2018.03.003
Itakura H, Yokoyama M, Matsuzaki M, et al. Relationships between plasma fatty acid composition and coronary artery disease. J Atheroscler Thromb. 2011;18:99-107. doi:10.5551/jat.5876