Behavior of plasma gastrin in obese subjects subjected to biliopancreatic bypass [Comportamento della gastrina plasmatica in soggetti obesi sottoposti a bypass biliopancreatico]

Biliopancreatic bypass for obesity entails a 2/3 distal gastrectomy with Roux-en-Y reconstruction, small bowel being transected at its midpoint and the enteroenterostomy placed 50 cm proximal to the ileocecal valve. Plasma fasting and meal-stimulated gastrin concentrations were measured by radioimmunoassay in 13 nonobese healthy volunteers, 13 pre-surgery obese patients, 11 patients within two months, 12 patients between four and twelve months and 7 patients between fifteen and twenty months after operation. There were no significant differences in fasting and meal-stimulated peak plasma gastrin levels between obese group and the control group and between any of the postoperative groups and the preoperative group. The 15-20 month post-surgery group mean fasting value was lower than in the other groups, whilst the mean peak value was unchanged. Integrated gastrin response was significantly higher in this group than in the preoperative group.