Change in hunger, fullness, ghrelin, PYY and GLP-1 in relation to a fixed test meal pre and post Rou-en-Y gastric bypass (RYGBS).

Abstract

Bariatric surgery is the most effective treatment for achieving long-term weight loss in clinically severe obese patients. This study examines changes in hunger, fullness and appetite hormones in relation to a fixed meal in patients pre and 5 months post-RYGBS. There were 10 severely obese, otherwise healthy premenopausal women, BMI=45.3±6.8 SD, % body fat (BODPOD)=53.6±6.0, age=35±9.3. Ratings of hunger and fullness immediately preceded blood draws at 0, 15, 30, 60 min in relation to a fixed complete liquid meal of Glytrol, 250 ml, 1kcal/ml, consumed at 0–10 min. The meal was presented at 2 pm following an overnight 18-h fast. Results revealed a decline in hunger prior to the meal ( p =.013) and an increase ( p =.009) in area under the curve (AUC) for fullness from pre to post 5 months. However, fasting ghrelin and AUC for ghrelin did not change from pre to post-5 months. AUC for PYY ( p =.009) and GLP-1 ( p =.004) increased from pre- to 5 months post-surgery. However, the change in hunger did not correlate with the change in fasting ghrelin and the change in fullness AUC did not correlate with the changes in AUC for GLP-1 or PYY. Moreover, the reduction in stomach capacity itself would not be able to help explain the reduction in premeal hunger post-surgery. Thus, other biological mechanisms to explain the changes in hunger and fullness post-RYGBS should be explored. Supported by NIH DK 61519 and MO1 RROO64529.