August 19th, 2014
Do Patients Really Have to Fast Before Lipid Testing?
CardioExchange’s Harlan M. Krumholz interviews Sripal Bangalore about his research group’s study of the prognostic value of non-fasting lipid panels. The study is published in Circulation.
Krumholz: Please briefly describe the high points of your article.
Bangalore: We questioned the value of “fasting” lipid panel measurement, given that people spend very little of their everyday lives fasting. Using NHANES-III data, we found that in terms of predicting long-term all-cause and cardiovascular mortality, fasting LDL was no better than non-fasting LDL. This also held true for total cholesterol and for triglycerides, thereby challenging the age-old practice of requiring people to fast before a lipid panel.
Krumholz: How does what you found align with prior reports?
Bangalore: Our report is aligned with prior reports that show similar results for triglycerides. Our findings confirm the data on triglycerides and expand the evidence base to LDL cholesterol and total cholesterol.
Krumholz: Non-fasting LDL may be predictive — but how should we think about it with regard to risk scores? Does it matter?
Bangalore: If one were to base it on the 2013 ACCF–AHA guidelines, the definition of 3 out of the 4 statin-benefit groups is based on LDL cholesterol levels. Risk scores are important, but the baseline LDL cholesterol level is also important.
Krumholz: What are you doing with your patients?
Bangalore: I am comfortable using a non-fasting lipid panel to make treatment decisions. It is convenient for the patient, and the prognostic value, as we show, is no different than that of the fasting lipid panel.
Krumholz: Finally, for non-fasting LDL, are there any calibration issues?
Bangalore: Prior studies have shown that LDL-cholesterol variability between fasting and non-fasting status is minimal, usually less than 10%. One would therefore not expect fasting lipid status to yield a significant reclassification of patients.
JOIN THE DISCUSSION
Do you think the age-old practice of making patients fast for a lipid panel is on its way out?