The oligosaccharide a-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 oligosaccharide a-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 a-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 a-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 2 d. Gastric emptying, blood glucose and serum insulin were measured after ingestion of a 300 ml drink containing 100 g sucrose, labelled with Tc-sulphur colloid, with or without 10 g a-cyclodextrin. Gastric emptying was slowed slightly by a-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 a-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 (P1⁄40·09) after a-cyclodextrin. We conclude that in a dose of 10 g, a-cyclodextrin has modest effects to slow gastric emptying of, and modify the glycaemic and insulinaemic responses to, oral sucrose, probably due to delayed intestinal carbohydrate absorption.