Gender differences in pharmacokinetics of alcohol.
Level 3 - non-randomized controlled study
Non-randomized controlled physiological and pharmacokinetic comparative study in healthy human volunteers
What was done
Sixty-five healthy male and female volunteers drank 0.3 g ethanol/kg body weight (as 5%, 10%, or 40% solutions) postprandially. Blood alcohol concentrations were measured by breath analysis and compared against intravenous infusion of the identical dose to quantify first-pass metabolism via Michaelis-Menten kinetics. Gastric emptying was evaluated via nuclear scanning using technetium-labeled DTPA in 10% ethanol, and alcohol dehydrogenase isozyme activities (gamma-ADH, sigma-ADH, and chi-ADH) were assessed in 58 gastric biopsies.
What was found
Women had less first-pass metabolism than men with 10% or 40% alcohol, but not 5% alcohol, which was associated with lower gastric chi-ADH activity in women. Alcohol gastric emptying was 42% slower in women, hepatic oxidation was 10% higher, and the volume of alcohol distribution was 7.3% smaller compared to men.
Why it matters
This study indicates that sex differences in blood alcohol levels are driven primarily by reduced gastric first-pass metabolism via lower chi-ADH activity rather than differences in gastric emptying or hepatic oxidation, explaining concentration-dependent vulnerabilities in women.
Limits
The abstract does not provide the sex breakdown of the 65 volunteers or the 58 biopsied subjects. Only a single dose (0.3 g/kg) in a postprandial state was evaluated, and statistical dispersion metrics (confidence intervals, p-values) were not reported in the abstract.
Cited by
- supports Women generally have lower gastric levels of alcohol dehydrogenase compared to men.