The effects of miglitol on glucagon-like peptide-1 secretion and appetite sensations in obese type 2 diabetics.
BACKGROUND
Previous studies reported that administration of first generation alpha-glucosidase inhibitors (AGIs), such as voglibose or acarbose, produced exaggerated and sustained postprandial responses of glucagon-like peptide-1 (GLP-1), an incretin hormone from the enteroinsular axis, in healthy humans. Little is known about the postprandial release of GLP-1 after AGI therapy in diabetics. GLP-1 plays a role to mediate satiety. Any agent that substantially elevates GLP-1 levels may theoretically reduce hunger, increase satiation and limit food intake.


OBJECTIVE
This study was performed to analyse the effect of miglitol, a more potent second generation AGI with fewer gastrointestinal side-effects, on the regulation of meal-related GLP-1 secretion and on the change of insulin-glucose dynamics as well as the release of gastric inhibitory polypeptide (GIP), another incretin hormone, after stimulation by an ordinary meal in obese type-2-diabetic subjects. Miglitol's subsequent influences on appetite sensations and food intake were also measured.


METHODS
In total, 8 obese type-2-diabetic women were randomized to receive treatment with 100 mg of miglitol or placebo three times a day for 2 days (six doses total) in a double-blind fashion. On day 3 of each treatment period (miglitol or placebo), measurements of GLP-1, GIP, insulin and glucose were taken periodically during 3 h after eating a 720 kcal breakfast. Appetite ratings with visual analogue scales (VASs) were used to assess ingestive behaviour hourly just before breakfast and hourly after for 6 h until immediately before lunch. The number of tuna sandwiches eaten at lunch was used to measure food consumption.


RESULTS
The plasma GLP-1, glucose, insulin and GIP levels in response to the mixed meal were compared after the miglitol and placebo treatment. Miglitol effectively enhanced postprandial GLP-1 release and suppressed plasma GIP secretion. The ingestion of a mixed meal induced a remarkable rise in GLP-1 after miglitol as compared with placebo in overweight diabetic subjects. The meal-related rise in GLP-1 after miglitol was significantly greater at all time-points between 30 and 180 min than after the placebo. The postprandial incremental area under the curve for GLP-1 with miglitol treatment was about twofold that with the placebo. The GLP-1 level reached a maximum at 120 min after the mixed meal and steadily rose throughout the rest of the 3-h study period. In the miglitol-treated condition, the average caloric intake at lunch during a 30-min eating period was 12% lower (p < 0.05) as compared with that after the placebo in six out of the eight subjects who exhibited a GLP-1 rise after the breakfast meal by greater than 30% from the placebo-treated condition. Correspondingly, the average rating scores were significantly lower for hunger feelings and markedly greater for sensations of satiety under the miglitol treatment; beginning 2 and 3 h, respectively, before the lunch test.


CONCLUSIONS
Miglitol induced an enhanced and prolonged GLP-1 release at high physiological concentrations after ingesting an ordinary meal in glycaemic-controlled diabetics. The excessive postprandial GLP-1 elevation after miglitol therapy modified feeding behaviour and food intake, and thereby has potential value in regulating appetite and stabilizing body weight in obese type-2-diabetic patients.
Lee
A
A
Department of Medicine, St Louis University Medical Center, and GRECC, St Louis VA Medical Center, St Louis, MO, USA.
Patrick
P
P
Wishart
J
J
Horowitz
M
M
Morley
J E
JE
D017485:1-Deoxynojirimycin / Q000031:analogs & derivatives; D000328:Adult; D000368:Aged; D001066:Appetite / Q000187:drug effects*; D003920:Diabetes Mellitus / Q000188:drug therapy* / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D005749:Gastric Inhibitory Polypeptide / Q000378:metabolism; D005934:Glucagon / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D050112:Imino Pyranoses; D008875:Middle Aged; D009765:Obesity; D010446:Peptide Fragments / Q000378:metabolism*; D019518:Postprandial Period / Q000187:drug effects; D011498:Protein Precursors / Q000378:metabolism*
D007004:Hypoglycemic Agents; D050112:Imino Pyranoses; D010446:Peptide Fragments; D011498:Protein Precursors; C045621:miglitol; D017485:1-Deoxynojirimycin; D005749:Gastric Inhibitory Polypeptide; D052216:Glucagon-Like Peptide 1; D005934:Glucagon; D005944:Glucosamine