Plasma cholecystokinin levels after vertical banded gastroplasty : effects of an acidified meal

BACKGROUND: Although cholecystokinin (CCK) is involved in the short-term regulation of satiety, it has not been investigated in obese patients subjected to bariatric restrictive operations. METHODS: 8 morbidly obese patients (BMI 49.1 +/- 6.9), 7F and 1M, were investigated before and after vertical banded gastroplasty (VBG). 6 healthy lean volunteers served as the control group. CCK was determined (RIA) after an overnight fast and after the administration of an acidified (pH 3) liquid meal. Blood samples were taken 45 min before the meal, 5 min after it and then every 30 min for 3 hours. RESULTS: There were no differences between groups in basal CCK levels. However, the peak of CCK after the meal was significantly higher (P <0.01) in obese patients after VBG (24.9 +/- 18 pmol/l) than before VBG (9.8 +/- 6.7 pmol/l) and when compared with the control group (8.0 +/- 6.3 pmol/l).The time needed to reach the peak was longer in healthy volunteers (105 +/- 24.9 min) than in obese patients before VBG (45 +/- 40 min) and after VBG (7.5+/- 12 min) (P<0.01). CONCLUSIONS: VBG increases the peak of CCK secretion and shortens the time to reach it. These changes could contribute to the satiety effects of gastric restrictive operations.