The oligosaccharide α-cyclodextrin has modest effects to slow gastric emptying and modify the glycaemic response to sucrose in healthy older adults

In healthy older subjects, the glycaemic response to carbohydrate-containing meals is dependent on gastric emptying and intestinal absorption; when the latter is slowed, the magnitude of the rise in glucose is attenuated. The oligosaccharicle alpha-cyclodextrin has been reported to diminish the glycaemic response to starch in young adults; this effect has been attributed to the inhibition of pancreatic amylase. We examined the effects of alpha-cyclodextrin on gastric emptying of, and the glycaemic and insulinaemic responses to, oral sucrose in healthy older subjects; as sucrose is hydrolysed by intestinal disaccharides, any effect(s) of alpha-cyclodextrin would not be attributable to amylase inhibition. A total of ten subjects (seven males and three females, age 68-76 years) were studied on 2d. Gastric emptying, blood glucose and serum insulin were measured after ingestion of a 300 ml drink containing 100g sucrose, labelled with Tc-99m-sulphur colloid, with or without 10 g alpha-cyclodextrin. Gastric emptying was slowed slightly by alpha-cyclodextrin; this effect was evident between 135 and 195 min and was associated with a slight increase (P < 0.05) in distal stomach retention. After alpha-cyclodextrin, blood glucose was slightly less (P < 0.05) at 60 min, and serum insulin was less (P < 0.0005) at 90 and 120 min. There was no difference in the incremental areas under the curve (iAUC) for blood glucose, but there was a trend for the iAUC for serum insulin to be lower (P=0.09) after alpha-cyclodextrin. We conclude that in a close of 10 g, alpha-cyclodextrin has modest effects to slow gastric emptying of, and modify the glycaemic and insulinaemic responses to, oral sucrose, probably clue to delayed intestinal carbohydrate absorption.