Abstract 11268: Fasting Low Density Lipoprotein Cholesterol (LDL-C) Levels Stratified by Fasting Time Do Not Have Significant Improvement in Prognostic Value versus Non-fasting LDL-C
Introduction: National guidelines recommend patients obtain fasting lipid panels for risk stratification. No studies have examined whether specific fasting time cut-points provide better prognostic ability for cardiovascular (CV) events in a national sample.
Hypothesis: We tested the hypothesis that fasting and non-fasting prognostic ability for all-cause and CV mortality is different within groups stratified by length of fast definition (4, 8, or 12 hours).
Methods: 16,161 individuals enrolled in the National Health and Nutrition Survey III linked to the National Death Index were stratified based on fasting status (<4 hours vs. ≥4 hours, <8 hours vs. ≥8 hours, <12 hours vs. ≥12 hours). CV and all-cause mortality were assessed after a mean of 14.0 (+/- 0.22) year follow-up. Risk of outcomes as a function of LDL-C and fasting status were stratified by cut-point and assessed using receiver operating characteristic (ROC) curves. Propensity score matching was performed after controlling for covariables in the 8 hour cut-point.
Results: For cardiovascular mortality, fasting LDL-C with a cut-point of 4 hours yielded similar prognostic value as that of non-fasting LDL-C (C statistics = 0.62 [95% CI 0.60-0.64] vs. C statistics = 0.65 [95% CI 0.59-0.70]; P=0.34), as did a cut-point of 8 hours (C-statistics = 0.62 [95% CI 0.60-0.64] vs. 0.62 [95% CI 0.59-0.64]; P=0.8) and 12 hours (C statistics = 0.61 [95% CI 0.59-0.63] vs. C statistics = 0.63 [95% CI 0.61-0.65]; P=0.27). Similar results were seen for the primary outcome for all cut-points. Propensity score matched models failed to reveal a significant difference between fasting and non-fasting cohorts.
Conclusions: This study shows similar prognostic value of fasting vs. non-fasting LDL-C on long-term mortality in a nationally representative U.S. cohort. National and international agencies should consider re-evaluating the recommendation that patients fast before obtaining a lipid panel.
Author Disclosures: B. Doran: None. Y. Go: Other Research Support; Modest; New York University School of Medicine Cardiovascular Outcomes Group. X. Xu: Other Research Support; Modest; New York University School of Medicine Cardiovascular Outcomes Group. H. Weintraub: None. S. Mora: Research Grant; Modest; Atherotech, AstraZeneca. Consultant/Advisory Board; Modest; Quest Diagnostics, Cerenis Therapeutics, Genzyme, Lilly. S. Bangalore: Consultant/Advisory Board; Modest; Pfizer Advisory Board.
- © 2014 by American Heart Association, Inc.