Abstract
BACKGROUND For decades, fasting for 8 to 12 hours has been recommended for measurement of lipid profiles. The effect of fasting on low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) has been described in healthy cohorts and those with stable disease states. Recently, guidelines suggested that fasting may not be necessary due to its small effect on lipid measures. Little is known, however, regarding whether the impact of fasting is altered in the setting of an acute coronary syndrome (ACS). HYPOTHESIS We hypothesized that the post-ACS period would minimally effect the impact of fasting status on lipid measurements. METHODS We evaluated the association of fasting on lipid and other biomarkers at the randomization visit, which occurred at a median of 7 days after the onset of an ACS, as well as during follow-up, in a cohort of 4177 subjects from the Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis In Myocardial Infarction 22 (PROVE IT-TIMI 22) trial. RESULTS Fasting samples were independently associated with a higher LDL-C of 4.1 mg/dL and apolipoprotein-B 100 of 2.6 mg/dL as well as a lower TG of 21.0 mg/dL and high-sensitivity C-reactive protein of 0.48 mg/dL. The relative difference was 3.8% for LDL-C and -11.3% for TG. Fasting did not change total cholesterol, high-density lipoprotein cholesterol, apolipoprotein A-I, lipoprotein(a), or apolipoprotein C-III. CONCLUSIONS Although fasting does impact lipid measurements, the effect on LDL-C is small (about 4 mg/dL), both early after ACS and during follow-up. These data provide support for recent guidelines that no longer advocate for fasting lipid samples, including in the setting of ACS.
