Fasting versus Nonfasting Triglycerides and the Prediction of Cardiovascular Risk: Do We Need to Revisit the Oral Triglyceride Tolerance Test?

Historically, triglycerides have been measured in the fasting state for 2 reasons. First, because of the marked increaseintriglyceridesafterfatingestion,thevariabil- ity in triglyceride measurements is much smaller in the fasting state. Second, before the availability of direct assays for LDL cholesterol (LDL-C),1 estimation of LDL-Cwasperformedinclinicalpracticealmostexclu- sively by use of the Friedewald equation, which re- quires that both the HDL-C concentration and the fasting triglyceride concentration divided by 5 be sub- tracted from the total cholesterol concentration. The recommendations to measure triglycerides in the fasting state did not, however, derive from a con- sistent set of prospective cohort studies showing that fasting concentrations were superior to nonfasting concentrations for the detection of cardiovascular risk. Instead, following screening guidelines, most epidemi- ologic investigations simply relied on fasting triglycer-