No effect of glucagon-like peptide-1 on short-term satiety and energy intake in man.
Centrally administered glucagon-like peptide-1 (GLP-1) inhibits feeding in fasted rats, but its role in human satiety has been largely unexplored. The present study investigated the effect of peripheral GLP-1 infusion on gastric emptying and satiety in man. Ten non-obese male subjects were infused in a randomized single-blind within-subject crossover study using saline infusion as control. They received either a GLP-1 infusion (1.2 pmol/kg per min) or a saline infusion for 1 h, at 18.00 hours. At 20 min after starting the infusion the gastric emptying of a 400 ml water load was measured. Subjects completed behavioural self-rating scales to assess hunger and satiety. After 40 min subjects were given a buffet meal ad libitum and their food intake was recorded. GLP-1 infusion raised circulating GLP-1 concentrations to approximately twice those seen following a meal. It did not affect circulating insulin levels but caused a small fall in glucose levels. Gastric emptying of the water load was significantly delayed by the GLP-1 infusion. Energy intake from the buffet was unaffected by GLP-1 infusion. Self-assessment of hunger and satiety was similarly unaffected by the infusion before the buffet meal, although subjects tended to be less hungry after the buffet meal following GLP-1 infusion (P < 0.09). GLP-1 infusion delayed gastric emptying but had a minimal effect on food intake and satiety. This study casts doubts on whether GLP-1 is a major satiety factor in man, although a raised circulating plasma glucose level, as would normally occur postprandially, might be necessary for GLP-1 to increase satiety.
Long
S J
SJ
School of Biological Sciences, University of Surrey, Guildford, UK.
Sutton
J A
JA
Amaee
W B
WB
Giouvanoudi
A
A
Spyrou
N M
NM
Rogers
P J
PJ
Morgan
L M
LM
D000328:Adult; D001069:Appetite Regulation / Q000187:drug effects; D018592:Cross-Over Studies; D004326:Drinking; D002149:Energy Intake / Q000187:drug effects*; D005746:Gastric Emptying / Q000187:drug effects; D005934:Glucagon / Q000097:blood / Q000494:pharmacology*; D052216:Glucagon-Like Peptide 1; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010446:Peptide Fragments / Q000097:blood / Q000494:pharmacology*; D011498:Protein Precursors / Q000097:blood / Q000494:pharmacology*; D012527:Satiation / Q000187:drug effects*; D016037:Single-Blind Method
D010446:Peptide Fragments; D011498:Protein Precursors; D052216:Glucagon-Like Peptide 1; D005934:Glucagon