For decades, fasting for 8 to 12 hours prior to blood draw has been the recommended guideline for measurement of lipid profiles. But does fasting have a clinically significant outcome on the results of lipid level measurement in patients? Using data provided by the Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis in Myocardial Infarction 22 (PROVE-IT-TIMI 22) trial, our group examined this question.
In a cohort of 4,177 subjects from the PROVE-IT-TIMI 22 trial, the association of fasting status on lipid measurements and other biomarkers were evaluated at randomization (a median of 7 days after the onset of an acute coronary syndrome [ACS]) and during follow-up. The impact of fasting compared with non-fasting, with and without multivariate adjustment, showed mean fasting levels were significantly higher for low-density lipoprotein-cholesterol (LDL‑C; 4.1 mg/dL) and apolipoprotein-B 100 (apoB; 2.6 mg/dL), but lower for triglycerides (21.0 mg/dL) and high-sensitivity C-reactive protein (hs‑CRP; 0.48 mg/dL). This association was observed at baseline and follow-up time points.
Our research supports a minimal impact on the lipid profile by requiring prior routine fasting. Advantages of not requiring fasting include making lipid assessment less burdensome for providers and patients, and decreasing laboratory resources needed to handle a large bolus of morning tests. The data from this trial provide support for recent guidelines that no longer advocate for fasting lipid samples, including in the setting of ACS.