Effects of glucose supplementation on gastric emptying, blood glucose homeostasis, and appetite in the elderly

The aims of this study were to evaluate the effects of dietary glucose supp lementation on gastric emptying (GE) of both glucose and fat, postprandial blood glucose homeostasis, and appetite in eight older subjects (4 males, 4 females, aged 65-84 yr). GE of a drink (15 ml olive oil and 33 g glucose d issolved in 185 ml water), blood glucose, insulin, gastric inhibitory polyp eptide (GIP) and glucagon-like peptide-1 (GLP-1), and appetite (diet diarie s, visual analog scales, and food intake at a buffet meal consumed after th e GE study) were evaluated twice, after 10 days on a standard or a glucose- supplemented diet (70 g glucose 3 times a day). Glucose supplementation acc elerated GE of glucose (P < 0.05), but not oil; there was a trend for an in crease in GIP (at 15 min, P = 0.06), no change in GLP-1, an earlier insulin peak (P < 0.01), and a subsequent reduction in blood glucose (at 75 min, P , 0.01). Glucose supplementation had no effect on food intake during each d iet so that energy intake was greater (P < 0.001) during the glucose-supple mented diet. Appetite ratings and energy intake at the buffet meal were not different. We conclude that, in older subjects, glucose supplementation 1) accelerates GE of glucose, but not fat; 2) modifies postprandial blood glu cose homeostasis; and 3) increases energy intake.