Additionally, several studies suggest that females eliminate systemic alcohol faster than males (205). Because most ethanol is metabolized in the liver, Kwo and collaborators (1998) investigated potential sex-related differences in liver volume and their relationship to AER. Using an intravenous alcohol clamp and radiological computerized tomography, they found no sex differences in liver volume or AER per unit liver volume, with both males and females eliminating, on average, 7.3 grams of ethanol per hour. However, because females typically have a larger liver volume relative to their lean body mass than males, they exhibited greater ethanol clearance per unit of lean body mass (206). A follow-up study using similar methods, which also included younger and older groups of males and females, found that regardless of the age group, males and females had similar AER per unit of liver volume (207). This study also replicated the finding that females, compared to males, have a larger liver volume relative to lean body mass. However, females in this sample had smaller absolute liver volumes and slower AER than males, highlighting the influence of liver volume as a source of variability in AER (207).
