Plasma leptin levels after vertical banded gastroplasty for morbid obesity : effects of an acidified meal

Background: Leptin is considered One of the anorectic messengers to the central nervous system in lean subjects. Although it is secreted by the gastric mucosa, there are contradictory evidences of its involvement in mediating the acute satiety effect of the meal in obese patients. The effects of restrictive operations on meal-stimulated leptin secretion are unknown. Methods: The effects of a standard acidified (pH 3) meal on leptin release were investigated in obese patients, before and after vertical banded gastroplasty (VBG). 8 morbidly obese patients (BMI 49.1+/-6.5) had serum leptin determination after an overnight fast. Samples were taken basally and every 30 minutes after the meal for 3 hours. The test was repeated after 20% BMI reduction. 5 lean volunteers (BMI 22.5+/-1.7) served as the control group. Results: In obese patients, basal serum leptin fell from 62+/-20.4 to 23.8+/-15.7 ng/ml after the operation (P<0.01) but still with significant differences vs the control group (5.6+/-3 ng/ml). The meal was associated with a significant decrease of serum leptin (ANOVA test, P<0.01), and significant differences between obese patients after surgery and lean subjects were found. Conclusion: Serum leptin was reduced by the meal in obese patients and VBG did not attain satiety through serum leptin changes.