Non-fasting versus fasting lipid profiles: A consensus recommendationNews - May 17, 2016
Fasting is not routinely required for determination of a lipid profile: clinical and laboratory implications including flagging at desirable concentration cut-points—a joint consensus statement from the European Atherosclerosis Society and European Federation of Clinical Chemistry and laboratory Medicine
Nordestgaard BG, Langsted A, Mora S, et al.
Eur Heart J 2016; April 26, published online ahead of print
It has never been proven that non-fasting lipid profiles are non-superior over fasting lipid profiles. Nevertheless, in clinical practice the lipid profile is conventionally measured after 8 hours of fasting. As most people regularly consume during the day and the postprandial state holds for over 24 hours, the 8 hours fasted lipid measurement may not reflect the daily average plasma lipid and lipoprotein concentrations [1,2]. Also for patients, laboratories, general practitioners and hospital clinicians, it would be more convenient and efficient to measure lipid levels in a non-fasting setting [3-7]. However, limitations of non-fasting lipid levels include (i) that levels may be less standardized, (ii) that they may be less accurate and therefore invalid for the Friedewald equation for LDL-c estimation, (iii) abnormal/normal lipid cut-points are not established.
This consensus paper states a critical evaluation of using non-fasting lipid profiles versus fasting lipid profiles and proposes recommendations on (i) situations when fasting is not required for a lipid profile and (ii) lipid levels that should be flagged as abnormal.
The paper briefly describes measurements of the lipid profile and several clinical studies that have been done regarding the response on lipids and lipoproteins following food intake. In addition, they mention several cohort studies that related non-fasting lipid profiles to the risk for CV events.
Based on these data, it is recommended by this joint consensus to use non-fasting lipid profiles in the majority of patients, while fasting samples may be considered with non-fasting plasma triglyceride levels >5 mmol/L (440 mg/dL). Exceptions are briefly mentioned. However, arguments against the use of non-fasting samples are also discussed, including the minor chance of CV risk misclassification and error in initiating statin therapy.
Non-fasting sample cut-points are recommended for abnormal triglyceride, total cholesterol, LDL-c, calculated remnant cholesterol, calculated non-HDL-c, HDL-c, apolipoprotein A1, apoB and Lp(a) levels, as well as these for fasting samples and life-threatening levels of these lipids and lipoproteins.
As of 2009, the Danish Society for Clinical Biochemistry already recommended using non-fasting lipid profile measurements over fasting profiles [8,9]. This was accompanied by the option to re-measure triglyceride concentrations in the fasting state, if non-fasting values were too high. To evaluate this approach, this joint consensus further updated, analysed and discussed the Danish study data. Moreover, an implementation strategy of such a system in individual countries is proposed.
Find this article online at http://www.ncbi.nlm.nih.gov/pubmed/27122601
1. Rifai N,Warnick GR. Lipids, lipoproteins, apolipoproteins, and other cardiovascular risk factors. In: Burtis CA, Ashwood ER, Bruns DE, (eds), Tietz Textbook of Clinical Chemistry and Molecular diagnostics, 4th ed. Philadelphia: Elsevier Saunders; 2006, p903–982.
2. Simundic AM, Cornes M, Grankvist K, Lippi G, Nybo M. Standardization of collection requirements for fasting samples: for the Working Group on Preanalytical Phase (WG-PA) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM). Clin Chim Acta 2014;432:33–37.
3. Langsted A, Freiberg JJ, Nordestgaard BG. Fasting and nonfasting lipid levels: influence of normal food intake on lipids, lipoproteins, apolipoproteins, and cardiovascular risk prediction. Circulation 2008;118:2047–2056.
4. Mora S, Rifai N, Buring JE, Ridker PM. Fasting compared with nonfasting lipids and apolipoproteins for predicting incident cardiovascular events. Circulation 2008;118: 993–1001.
5. Watts GF, Cohn JS. Whither the lipid profile: feast, famine, or no free lunch? Clin Chem 2011;57:363–365.
6. Gaziano JM. Should we fast before we measure our lipids? Arch Intern Med 2012; 172:1705–1706.
7. Khera AV, Mora S. Fasting for lipid testing: is it worth the trouble? Arch Intern Med 2012;172:1710–1712.
8. Nordestgaard BG, Hilsted L, Stender S. Plasmalipider hos ikkefastende patienter og signalværdier pa° laboratoriesvar. Ugeskr Laeger 2009;171:1093.
9. Langsted A, Nordestgaard BG. Nonfasting lipids, lipoproteins, and apolipoproteins in individuals with and without diabetes: 58 434 individuals from the Copenhagen General Population Study. Clin Chem 2011;57:482–489.