Glucose tolerance in chronic alcoholics after alcohol withdrawal: effect of accompanying diet

The effect of alcoholism or acute alcohol ingestion on carbohydrate metabolism is not clear. The metabolic features of alcoholics cannot be easily achieved in normal men submitted to investigations concerning the effects of alcohol on glucose tolerance. Undernutrition and/or malnutrition characterize the eating behavior of alcoholics. It is also well-known that diet is an important determinant of carbohydrate tolerance. Thus, we studied the effects of a controlled diet on glucose tolerance and insulin release in a group of chronic alcoholics, with or without withdrawal from alcohol. Twenty-two subjects took part in the study; their mean caloric intake was 2,805 +/- 91 kcal/d, 58% of which was due to alcohol. In all subjects five days after an isocaloric diet and no alcohol, we performed an oral glucose tolerance test (OGTT). After that, the subjects were divided into three subgroups: group A, eight subjects with alcohol withdrawal and an 17.5 kcal/kg/d diet; group B, eight subjects with alcohol withdrawal and a 35 kcal/kg/d diet, and group C, six subjects with a 35 kcal/kg/d diet plus ethanol 200 g/d. After 3 weeks a second OGTT was performed. We found a significant improvement of the glucose tolerance and of the release of insulin in group B as well as group C; the alcohol withdrawal per se was irrelevant to the observed modifications of the glucose tolerance. Our data suggest that a poor diet would be a major cause of carbohydrate intolerance in alcoholics.