Not really. According to a recent study involving 209,180 individuals, fasting times showed little association with lipid levels in a community-based population (Arch Intern Med 2012; 172: 1707-10).
Although current guidelines suggest obtaining lipid levels after fasting, lipid levels do not vary much between fasting and nonfasting states. Furthermore, fasting may not be reflective of the patient’s typical metabolic state.
Design: cross-sectional study over a 6-month period in 2011 (Calgary) using a large community-based cohort. The average age of the participants was 52.8 years.
Results: In tables 1 and 2, the authors provide the cholesterol values for fasting times that varied from 1 hour to 16 hour. The vast majority fasted for 10 hours or more. For example, less than 1% of the cohort fasted for only 1 hour. However, fasting time showed little association with lipid subclass levels, suggesting that fasting for routine levels is not necessary.
There were several limitations of the study. The meal choices in the nonfasting groups were not known and the study was not randomized. In addition, LDL values were not calculated when triglycerides were >400 mg/dL; this represented 1.5% of the study population. The authors recommend that in individuals with triglycerides >400 mg/dL that fasting lipid levels could be considered.
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