EFFECT OF GLUCOSE SUPPLEMENTATION ON APPETITE AND THE PYLORIC MOTOR RESPONSE TO INTRADUODENAL GLUCOSE AND LIPID

The effects of different macronutrients on appetite and pyloric motili ty and the impact of short-term dietary glucose supplementation on the se responses were evaluated. Ten males (aged 19-38 yr) received isocal oric (2.9 kcal/min) intraduodenal infusions of glucose and lipid while antropyloroduodenal motility and appetite were assessed by manometry and visual analog scales, respectively. Effects of each intraduodenal nutrient on appetite and motility were evaluated before and after 7 da ys of dietary supplementation with glucose (400 g daily). Initially, b oth nutrients caused a similar rise in pyloric tone, but intraduodenal lipid was a more potent stimulus of phasic pyloric motility (P = 0.05 ) and suppressed appetite more (P = 0.013) than intraduodenal glucose. After dietary glucose supplementation, the increase in pyloric tone d uring intraduodenal glucose was attenuated. Although intraduodenal lip id remained a more potent stimulant of phasic pyloric motility (P = 0. 016), it no longer decreased appetite. We conclude that in healthy you ng males 1) intraduodenal infusion of lipid is a more potent stimulus of phasic pyloric motility and suppresses appetite more than intraduod enal glucose and 2) dietary glucose supplementation alters both the ap petite suppressant effect of intraduodenal lipid and the pyloric motor response to intraduodenal glucose infusion.