Preoperative oral rehydration therapy with 2.5 % carbohydrate beverage alleviates insulin action in volunteers

Preoperative carbohydrate loading enhances insulin action by approximately 50 %. In some Japanese hospitals, preoperative oral rehydration therapy is performed for preventing dehydration during surgery. We hypothesized that preoperative oral rehydration therapy with a 2.5 % carbohydrate beverage that is widely used in Japan can enhance insulin action. Therefore, we investigated the effect of this 2.5 % carbohydrate beverage on insulin action in volunteers. Six healthy volunteers participated in this crossover randomized study. The participants were segregated into 2 groups: an oral rehydration therapy with 2.5 % carbohydrate beverage group (group A) and a control group (group B). Subjects in group B were allowed to drink only water from 9 pm the day before the test; conversely, group A fasted from 9 pm onward and drank 500 ml of the beverage containing 2.5 % carbohydrate (OS-1; Otsuka Pharmaceutical Factory, Tokushima, Japan) between 9 and 12 pm and again at 6.30 am. At 8.30 am, a hyperinsulinemic normoglycemic clamp was initiated using an artificial pancreas STG-22 (Nikkiso, Tokyo, Japan). Insulin action was evaluated in both groups using the glucose infusion rate. Blood glucose levels at the initiation of the clamp procedure were similar. However, the glucose infusion rate for group A was significantly higher than that of group B (8.6 ± 1.5 vs. 6.8 ± 2.0 mg/kg/min, p = 0.009). In conclusion, the hyperinsulinemic normoglycemic clamp using an artificial pancreas showed that the administration of a 2.5 % carbohydrate oral rehydration solution for preoperative oral rehydration therapy improves insulin action in volunteers.