Introduction Fatty Acid Ethyl Esters (FAEEs) are non-oxidative metabolites of ethanol present in serum for at least 24 hours after ethanol ingestion. Ethyl palmitate, ethyl oleate, and ethyl stearate are prominent FAEEs in human serum that may have utility as indicators of ethanol use.
Purpose We assessed for differences in FAEE levels associated with fed and fasting states after acute alcohol ingestion.
Methods Paired data for fed and fasting study phases were obtained for four males and seven females after informed consent, as approved by our institutional review board. In the fed phase, participants ingested a standard alcoholic drink (0.3 g EtOH/kg body weight) after a standard meal. Participants in the fasting phase ingested a standard alcoholic drink after a 5-hour fast. Meals standardized for caloric content (kcal/kg body wt.) and macronutrients were served on the day of the study. Serum lipids were sampled prior to alcohol ingestion. Blood alcohol level (BAL) and FAEE concentration analyzed by gas chromatography-mass spectrometry were determined 30 min. after ingestion.
Results Total FAEE levels (ethyl palmitate, ethyl oleate, and ethyl stearate) varied widely and were not significantly different in the fed, 543±149 nM (95% CI, a = 0.05) vs. fasting phases, 779±245 nM (p = 0.16, n=11, paired data). Correlations between total FAEE and BAL did not vary widely between the fed, r = 0.812 (95% CI: 0.414-0.949) and fasting state, r = 0.714 (0.200-0.920). In the fasting state, ethyl palmitate/HDL and ethyl stearate/HDL best correlated with BAL (r=0.814, 0.803, respectively, p=0.002,0.003). In the fed state, ethyl oleate/triglyceride best correlated with BAL (r=0.894, p≤0.000).
Conclusion We observed no significant differences in peak FAEE levels associated with feeding status after acute ingestion of alcohol.Normalization for certain serum lipids can slightly improve correlation of FAEE and BAL. Fed or fasting status is not likely to have a large impact on the use of FAEEs as indicators of ethanol ingestion.