Effects of metformin on glucagon-like peptide-1 levels in obese patients with and without Type 2 diabetes.
Metformin has been shown to increase glucagon-like peptide-1 (GLP-1) levels after an oral glucose load in obese non-diabetic subjects. In order to verify if this effect of the drug was also present in obese Type 2 diabetic patients who have never been treated with hypoglycemic drugs, 22 Type 2 diabetic and 12 matched non-diabetic obese patients were studied. GLP-1 was measured before and after a 100 g glucose load at baseline, after a single oral dose of 850 mg of metformin, and after 4 weeks of treatment with metformin 850 mg three times daily. Post-load GLP-1 levels were significantly lower in diabetic patients. A single dose of metformin did not modify GLP-1 levels. After 4 weeks of treatment, fasting GLP-1 increased in diabetic patients (3.8 vs 4.9 pmol/l; p<0.05), while the incremental area under the curve of GLP-1 significantly increased in both diabetic [93.6 (45.6-163.2) vs 151.2 (36.0-300.5) pmol x min/l; p<0.05] and non-diabetic [187.2 (149.4-571.8) vs 324.0 (238.2-744.0) pmol x min/l; p<0.05] subjects. In conclusion, GLP-1 levels after an oral glucose load in obese type 2 diabetic patients were increased by 4 weeks of metformin treatment in a similar fashion as in obese subjects with normal glucose tolerance.
Mannucci
E
E
Section of Diabetology, Geriatric Unit, Department of Critical Care, University of Florence, Italy.
Tesi
F
F
Bardini
G
G
Ognibene
A
A
Petracca
M G
MG
Ciani
S
S
Pezzatini
A
A
Brogi
M
M
Dicembrini
I
I
Cremasco
F
F
Messeri
G
G
Rotella
C M
CM
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications; D005215:Fasting; D005260:Female; D005934:Glucagon / Q000097:blood*; D052216:Glucagon-Like Peptide 1; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000097:blood; D008297:Male; D008687:Metformin / Q000008:administration & dosage*; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000150:complications*; D010446:Peptide Fragments / Q000097:blood*; D011498:Protein Precursors / Q000097:blood*
D001786:Blood Glucose; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; D010446:Peptide Fragments; D011498:Protein Precursors