1. Circulating glucagon-like peptide-1 increases in response to short-term overfeeding in men
- Author
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Guang Sun, Danny Wadden, Jon G. Church, Peyvand Amini, Farrell Cahill, Edward Randell, Sudesh Vasdev, and Yanqing Yi
- Subjects
Nutritional regulation ,medicine.medical_specialty ,endocrine system ,Calorie ,Endocrinology, Diabetes and Metabolism ,Medicine (miscellaneous) ,Clinical nutrition ,Overweight ,Energy homeostasis ,Insulin resistance ,Internal medicine ,Diabetes mellitus ,medicine ,Obesity ,Overfeeding ,Nutrition and Dietetics ,business.industry ,Research ,digestive, oral, and skin physiology ,Diabetes ,medicine.disease ,Glucagon-like peptide-1 ,Endocrinology ,medicine.symptom ,business ,GLP-1 ,hormones, hormone substitutes, and hormone antagonists - Abstract
Background Glucagon-like Peptide-1 (GLP-1) is an incretin hormone secreted from the gastrointestinal tract that facilitates the glucose-dependent insulin response. Additionally, GLP-1 is thought to be involved in energy homeostasis. Currently little is known about GLP-1’s responsiveness to an energy surplus, a fundamental cause of obesity and diabetes. Our objective was to examine the response of serum GLP-1 to short-term (7 day) overfeeding in young men. Methods Seventy-two young men from the Canadian province of Newfoundland were recruited for the study. For 7-days, the subjects consumed 70% more calories than required at baseline. Various measurements including: anthropometrics, body composition, markers of glucose/lipid metabolism and serum total GLP-1, were taken at a fasted state before (day 1) and after (day 8) the challenge. Paired t-test analyses were used to assess the change in variables after the overfeeding period. Additionally, the relationship between serum GLP-1 and the measured variables at baseline and change due to overfeeding were analyzed. Results Serum GLP-1 was significantly increased in all groups in response to the 7-day energy surplus, indicating the increase was independent of adiposity status. There was no significant difference in fasting GLP-1 at baseline between the normal weight and overweight/obese groups. At baseline, GLP-1 concentration negatively correlated with HDL-cholesterol and positively correlated with triacylglycerols and markers of insulin resistance in the overweight/obese group. Also GLP-1 was negatively correlated with change in percent gynoid fat in the overweight/obese subjects. Percent change in GLP-1 was negatively associated with percent change in gynoid fat in the normal weight group and positively associated with percent change in cholesterol in the overweight/obese group. Percentage change of circulating triacylglycerols was positively associated with percent change in GLP-1 in both adiposity groups. Conclusion Our findings showed that GLP-1 serum concentration is not a significant factor in determining obesity status. The increase of GLP-1 in all subjects regardless of obesity status, suggest GLP-1 serves as a protective role, counteracting energy surplus.
- Published
- 2013