Nonfasting LDL-C as a Predictor of Cardiovascular Event Risk
ABSTRACT
Background: Cardiovascular health is often assessed through predictive tools that rely upon measured lipid values. It has long been held that lipids were most accurately measured with the patient in the fasting state; however, mounting evidence has suggested that nonfasting lipid measurements are not significantly different from fasting. This systematic review examined the cardiovascular disease predictive value of nonfasting lipid levels, specifically LDL-C, compared to fasting lipid measurements.
Methods: An exhaustive literature search was conducted using the following search engines: MEDLINE-Ovid, Web of Science, and CINAHL. The following keywords were used: fasting, nonfasting, cholesterol, lipids, and cardiovascular. Eligible studies were assessed for quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).
Results: Three studies met inclusion criteria. Two were prospective cohort studies and one was a combined cross-sectional and prospective cohort study. Two of the studies agreed that nonfasting lipid values were of similar prognostic value with regards to cardiovascular events. The third article concluded that nonfasting LDL-C was not of predictive value and should not be used.
Conclusion: Nonfasting LDL-C levels, when elevated, correlated with an increase in cardiovascular events and have similar predictive power to fasting measurements. Total cholesterol and HDL-C levels do not deviate significantly between fasting and nonfasting states and it is reasonable to use these values to calculate 10-year cardiovascular disease risk. Thus requiring the patient to fast prior to phlebotomy for lipid measurement is an unnecessary practice.
Keywords: Nonfasting LDL cholesterol, cardiovascular risk
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REVIEWED STUDIES:
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Doran B, Guo Y, Xu J, et al. Prognostic value of fasting versus nonfasting low-density lipoprotein cholesterol levels on long-term mortality: Insight from the national health and nutrition examination survey III (NHANES-III). Circulation. 2014;130(7):546-553. Accessed 20140812.
Mora S, Rifai N, Buring JE, Ridker PM. Fasting compared with nonfasting lipids and apolipoproteins for predicting incident cardiovascular events. Circulation. 2008;118(10):993-1001. Accessed 20080903.
AUTHOR: Richard Nile is currently completing his second year in the School of PA Studies at Pacific University, Oregon. He will graduate with an MS degree in August, 2016.