Differences in the Synthesis and Elimination of Phosphatidylethanol 16:0/18:1 and 16:0/18:2 After Acute Doses of Alcohol.

ABSTRACT

BACKGROUND: The purpose of this study was to examine the synthesis and elimination of phosphatidylethanol (PEth) 160/181 and 160/182 following the consumption of alcohol among 56 light and heavy drinkers. METHODS: A transdermal alcohol monitor was used to promote alcohol absence 7 days prior, and 14 days after, alcohol consumption in the laboratory. Participants consumed a 0.4 or 0.8 g/kg dose of alcohol in 15 minutes. Blood and breath samples were collected before, at various times up to 360 minutes postconsumption, and 2, 4, 7, 11, and 14 days after alcohol consumption. Initial rates of PEth synthesis, 360 minutes area under the PEth pharmacokinetic curves (AUCs), and elimination half-lives were determined. RESULTS: (i) Nonzero PEth levels were observed before alcohol dosing for most participants, despite 7 days of alcohol use monitoring; (ii) 0.4 and 0.8 g/kg doses of alcohol produced proportional increases in PEth levels in all but 1 participant; (iii) the initial rate of synthesis of both PEth homologues did not differ between the 2 doses, but was greater for PEth 160/182 than PEth 160/181 at both doses; (iv) the mean AUC of both PEth homologues was higher at 0.8 g/kg than at 0.4 g/kg; (v) the mean AUC of 160/182 was greater than that of PEth 160/181 at both alcohol doses; (vi) the mean half-life of PEth 160/181 was longer than that of PEth 160/182 (7.8 ± 3.3 [SD] days and 6.4 ± 5.0 [SD] days, respectively); and (vii) there were no sex differences in PEth 160/181 or 160/182 pharmacokinetics. CONCLUSIONS: The results of this study support the use of PEth 160/181 and 160/182 as biomarkers for alcohol consumption. Because of consistent pharmacokinetic differences, the levels of these 2 PEth homologues may provide more information regarding the quantity and recentness of alcohol consumption than either alone.