Nonfasting Sample for the Determination of Routine Lipid Profile: Is It an Idea Whose Time Has Come?

Abstract

For many years the determination of a routine lipid profile (total, LDL, and HDL cholesterol and triglycerides) has been done routinely in the clinical laboratory using a blood specimen that is collected in the fasting state. The rationale for such a requirement includes 1) the postprandial changes in lipoprotein composition known to occur, particularly the increases in triglycerides (TG)10 concentration which have a direct relation to the meal fat and carbohydrate content, 2) the clinically significant effects of increased TG (>400 mg/dL; 4.5 mmol/L) on the calculation of LDL cholesterol (LDL-C) when using the Friedewald equation, and 3) the use of fasting samples for lipid measurement in many clinical trials and epidemiological studies on which treatment goals are based. However, because most of each person's lifetime is spent in the postprandial state, the wisdom of collecting a fasting sample to determine future risk of cardiovascular disease has been challenged. In addition, recent evidence has demonstrated that nonfasting TG concentrations are a better predictor of future coronary events compared to fasting TG, in both men and women. The Danish Society for Clinical Biochemistry, in 2009, and the UK National Institute of Clinical Excellence (NICE), in 2014, recommended the use of a nonfasting specimen for the determination of routine lipid profile; both entities acknowledge that in certain situations a fasting sample is required. The European Atherosclerosis Society and the European Federation of Clinical Chemistry and Laboratory Medicine will be making a similar recommendation. In contrast, the 2013 guidelines released by the American College of Cardiology/American Heart Association (ACC/AHA) preferred a fasting specimen for lipid testing. Such inconsistencies in published guidelines will complicate the interpretation of the literature and confound metaanalyses. The decision of whether to use a fasting or nonfasting sample, however, will be driven not only by the strong epidemiologic …