Booze hampers the hemoglobin's ability to carry oxygen thru your body. Increasing the cabin altitude (can't really do that in an MD-88 without going manual) in a real round-a-bout way decreases the amount of oxygen (well, air actually) which may in fact push the already oxygen deprived (intoxicated?) passenger over the edge and into the murky goo of unconsciousness.
Or umm, something like that.
