Endocrine Abstracts

Background: Food intake and body weight are in a constant sense of balance, which is tightly regulated. The central control of appetite by the hypothalamus and areas in the brainstem has been established. The peripheral regulation of appetite via gut hormones has also been alluded to – previous studies have shown PYY and ghrelin hormones to be altered in obesity. Glucagon-like peptide-1 is a gut hormone released from L-cells in the distal ileum and colon. It has been implicated in the short-term control of appetite and an altered GLP-1 response in obesity has been proposed.

Aim: To assess GLP-1 responses following multiple meals in lean and obese subjects.

Methods: Venous blood samples collected from 20 obese and 20 lean subjects in response to six standard meals at different calories: 250, 500 and 1000 kcal in 500 ml and 1000, 2000, 3000 kcal in 900 ml. Blood samples were taken every 30 min. GLP-1 levels were measured using an in-house RIA. Approved by Local Research and Ethics Committee.

Results: There was no difference in the fasting GLP-1 levels in the obese and lean groups. The peak GLP-1 levels showed no difference between the two groups. The pre- and postprandial GLP-1 response over 180 min was similar between lean and obese subjects.

Conclusion: The GLP-1 response to meals at differing caloric meals was similar between lean and obese subjects. No significant difference was found between fasting GLP-1 levels and peak GLP-1 levels. This suggests that the GLP-1 responses are not altered in obesity.