Glucagon-like peptide (GLP)-1 and leptin concentrations in obese patients with Type 2 diabetes mellitus
Version of Record online: 9 OCT 2008
Volume 17, Issue 10, pages 713–719, October 2000
How to Cite
Mannucci, E., Ognibene, A., Cremasco, F., Bardini, G., Mencucci, A., Pierazzuoli, E., Ciani, S., Fanelli, A., Messeri, G. and Rotella, C. M. (2000), Glucagon-like peptide (GLP)-1 and leptin concentrations in obese patients with Type 2 diabetes mellitus. Diabetic Medicine, 17: 713–719. doi: 10.1046/j.1464-5491.2000.00367.x
- Issue online: 9 OCT 2008
- Version of Record online: 9 OCT 2008
- Accepted 25 July 2000
- euglycaemic hyperinsulinaemic clamp;
- glucagon-like peptide-1;
- Type 2 diabetes mellitus
Aims To assess differences in circulating leptin and glucagon-like peptide (GLP)-1 concentrations before and after an oral glucose load, in euglycaemic and isoinsulinaemic conditions, between obese patients with and without Type 2 diabetes mellitus.
Methods Ten male obese (body mass index (BMI) > 30 kg/m2) patients with Type 2 diabetes and 20 matched non-diabetic subjects were studied. Leptin, GLP-1(7–36)amide and GLP-1(7–37) concentrations were measured 0, 30, 60, and 90 min after a 50-g oral glucose load administered 90 min after the beginning of a euglycaemic hyperinsulinaemic clamp.
Results GLP-1(7–36)amide concentrations before the glucose load were significantly lower in diabetic patients than in controls (median (quartiles): 50.5 (44.7–53.2) vs. 128.7(100–172.5) pg/ml; P < 0.01), while no difference was observed in baseline GLP-1(7–37). In non-diabetic subjects, GLP-1(7–36)amide and GLP-1(7–37) concentrations increased significantly after the oral glucose load, while no glucose-induced increase in GLP-1 concentration was observed in diabetic patients. GLP-1(7–36)amide at 30, 60, and 90 min, and GLP-1(7–37) at 30 min, of the glucose challenge, were significantly lower in diabetic patients. Leptin concentrations were not significantly different in diabetic patients when compared to non-diabetic subjects, and they did not change after the oral glucose load.
Discussion Leptin concentrations are not significantly modified in obese Type 2 diabetic patients. GLP-1(7–36)amide baseline concentrations are reduced in Type 2 diabetes; moreover, diabetic subjects show an impaired response of GLP-1 to oral glucose in euglycaemic, isoinsulinaemic conditions. This impairment, which is not the result of differences in glycaemia or insulinaemia during assessment, could contribute to the pathogenesis of hyperglycaemia in Type 2 diabetes mellitus.