Endocrine Abstracts

Objective: Assess the effect of bariatric surgery on serum glucagon like peptide-1 (GLP-1) concentration and metabolic and biochemical parameters pre and postoperatively.

Methods: This prospective study comprised 50 subjects divided into 3 groups. Group 1: 20 obese subjects with T2DM (BMI >35) that underwent Roux-en-y gastric bypass surgery; Group 2: 20 lean subjects with T2DM and Group 3: 10 lean subjects as healthy controls.

Body weight, BMI and waist/hip ratio were analyzed. Fasting and 2hPP plasma glucose, HbA1c, lipid profile, fasting serum insulin and glucagon like peptide-1 (GLP-1) were tested.

For Group 1, tests were done twice, preoperative and 3 months after surgery. Insulin resistance was quantified using HOMA-IR.

Results: Fasting GLP-1 levels were lower in group 1 subjects compared to the other 2 groups (4.33±1.10 vs 5.21±0.89, 6.14±0.42 ng/ml, P<0.001). 2hPP GLP-1 levels were lower in Group 1 compared to the other 2 groups respectively (4.94±1.17 vs 6.04±0.99, and 9.32±0.97 ng/ml, P<0.001); also the difference between groups 2 and 3 was statistically significant. Fasting and 2hPP GLP-1 levels showed significant negative correlation with all metabolic parameters except HDL-C, which showed highly significant positive correlation. In Group 1, mean preoperative BMI was 47.3±4.2 vs 42.10±3.05, 3 months postoperatively. FBS was 145.9±19.2 vs 98.25±16.03 mg/dl, 2hPP was 208.9±33.2 vs 137.85±14.90 mg/dl, HbA1c was 9.6 vs 7.1% and fasting insulin was 20.9 vs 7.25 μIU, There were increase in the 2 hPP GLP-1 levels (4.9±1.2 vs 9.78±1.9 ng/ml) and HDL (34.1 vs 48.05 mg/dl). The level of significance was P<0.001 for all variables.

Conclusion: Bariatric surgery resulted in a statistically significant reduction in BMI and all metabolic parameters. 2h PP GLP-1 is low in diabetic patients. Postoperative 2hPP GLP-1 levels increased, possibly responsible for the metabolic benefits.