It has been shown that advanced age results in a decreased first pass metabolism (FPM) of ethanol with elevated serum ethanol concentrations (SECs). It is still unknown if this is due to age by itself or to other factors like for example atrophic gastritis with decreased activity of alcohol dehydrogenase (ADH). To study the effect of age on SECs and on bioavailability of ethanol, 15 volunteers with a mean age of 71 +/- 1 year (8males and 7 females) and 16 volunteers with a mean age of 37 +/- 2 years (8males and 8 females) showing normal gastric histology received ethanol (0.225 g/kg b. w.) intravenously (iv.) and orally.
Results: The difference between the SEC time curves after iv. and oral ethanol administration (so called FPM of ethanol) was significantly increased in elderly subjects (54 +/- 6 vs. 12 +/- 9 %, p < 0.001). The SEC time curves after iv. ethanol application were significantly increased in the elderly (p < 0.001), whereas SECs following oral alcohol administration were significantly lower in elderly as compared to younger individuals (p < 0.02). Peak SECs following iv. application was also significantly elevated with age (52 +/- 4 vs. 31 +/- 1 mg/100 ml, p < 0.001) and occurrence of peak SECs following oral ethanol intake was significantly delayed (47 +/- 4 vs. 28 +/- 4 min, p < 0.001). No gender effect at all was observed.
Conclusion: FPM of ethanol is inexpectedly increased in elderly with normal gastric morphology compared to young people. The elevation of SECs after iv. ethanol administration in the elderly could be explained by the reduction of the water distribution space with age, whereas the increased FPM of ethanol in elderly subjects with normal gastric morphology is probably due to a deceleration of the speed of gastric emptying leading to an increased contact time of alcohol with gastric alcohol dehydrogenase (ADH). Our data do not confirm results from other research groups showing increased SECs in the elderly after alcohol consumption. Increased SECs are therefore not due to age by itself, but are probably caused by other factors as for example atrophic gastritis which is frequently found in the elderly people and which decreases FPM of ethanol.