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 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) 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.
The decision of whether to use a fasting or nonfasting sample, will be driven not only by the strong epidemiologic and clinical evidence and the convenience to clinicians and patients but also by the reliability of the analytical techniques used in the measurement of these analytes. To address this issue, Clinica Chemistry invited a group of experts consisting of cardiologists, epidemiologists, clinical researchers, and clinical chemists to share their views on this topic.
Nonfasting Sample for the Determination of Routine Lipid Profile: Is It an Idea Whose Time Has Come?