Ghrelin and PYY are gastrointestinal peptides involved in appetite regulation. The cholinergic part of the vagal nerve participate in the regulation of glucose and insulin levels. We aimed to examine the effects of the cholinergic antagonist atropine on ghrelin, PYY, glucose and insulin under basal conditions and after meal ingestion in lean and obese subjects. Eight lean and eight obese subjects received in a randomized, double-blind, placebo controlled crossover study design (1) placebo, (2) placebo+breakfast, (3) atropine and (4) atropine+breakfast. Plasma ghrelin, PYY, insulin and glucose were measured. Hunger and satiety feelings were rated on 10 cm visual analog scales. In lean individuals atropine led to a decrease in plasma ghrelin and to a significant decrease in both basal and meal induced PYY concentrations. In obese subjects atropine did not significantly change ghrelin or PYY concentrations whereas it induced a comparable increase in heart rate and in meal induced glucose concentrations in the two study groups. Only lean, but not obese subjects experienced sustained feelings of satiety after breakfast. We suggest that the impaired cholinergic regulation of the postprandial drop in ghrelin concentrations and rise in PYY concentrations might be part of the deregulated food intake in obese subjects.
03 - 07 May 2008
European Society of Endocrinology