Endocrine Abstracts

Different hypothesis exist about the mechanism of glycose control after bariatric surgery involving intestinal bypass. The aim of our study was to determine the insulin and C-peptide response after test meal (Fresubin drink a 200 ml; 200 kcal, 15% protein, 30% fat and 55% carbohydrate) before (day 0) and 5 days after gastric by pass surgery. Glycaemia (mmol/l; glucose oxidase), insulin (ECLIA, Roche Diagnostics, pmol/l) and C-peptide (ECLIA, Roche Diagnostics, pmol/l) were determined in 22 obese patients (age: 36.22±12.66; BMI: 44.60±4.31 kg/m²) in two separate days in 0, 15, 30, 45, 60, 90 and 120 min. There were no significant difference between areas under the glucose curve (X±S.D.; 645.562±20.545 vs 621.600±24.071 mmol/l per min; P=0.304) and under the C-peptide curve (293 074.125±23 539.975 vs 267 750.375±19 685.409 pmol/l per min; P=0.317) while there was significant lower area under the insulin curve in day 5 (38 263.075±6079.509 vs 23 539.875±2571.388 pmol/l per min; P=0.032). There was significant difference between basal glucose in 0 vs 5 day (4.695±0.168 vs 4.090±0.177; P=0.0113) while there were no significant difference between basal insulin (100.514±24.191 vs 61.229±7.166; P=0.118) and C-peptide (1400.952±180.160 vs 1074.571±96.986; P=0.097). There were no significant difference between peak levels in glucose (6.330±0.218 vs 6.165±0.236; P=0.482), insulin (635.555±103.576 vs 416.145±52.408; P=0.066) and C-peptide (3300.900±279.453 vs 3286.800±280.226; P=0.960) in day 0 and 5. In conclusion, insulin response after test meal is significantly decreased after gastric by pass surgery after 5 days without significant difference in glucose response, indicating early improvement in insulin sensitivity.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.