Short-term effects of gastric bypass surgery on circulating ghrelin levels.
OBJECTIVE
To prospectively evaluate the short-term effects of Roux-en-Y gastric bypass (RYGBP) on ghrelin secretion and its relevance on food intake and body weight changes.


METHODS
Ghrelin response to a standardized test meal was evaluated in eight obese patients (BMI, 43.5 to 59.1 kg/m2) before and 6 weeks after RYGBP. Ghrelin response was compared with that of an age-matched group of six normal weight individuals (BMI, 19.6 to 24.9 kg/m2).


RESULTS
Fasting serum ghrelin levels were lower in obese subjects compared with controls (p < 0.05). Meal ingestion significantly suppressed ghrelin concentration in controls (p < 0.05) and obese subjects (p < 0.05), albeit to a lesser degree in the latter group (p < 0.05). Despite a 10.3 +/- 1.5% weight loss, fasting serum ghrelin levels were paradoxically further decreased in obese subjects 6 weeks after RYGBP (p < 0.05). Moreover, at this time-point, food intake did not elicit a significant ghrelin suppression. The changes in ghrelin secretion after RYGBP correlated with changes in insulin sensitivity (p < 0.05) and caloric intake (p < 0.05).


CONCLUSIONS
This study showed that the adaptive response of ghrelin to body weight loss was already impaired 6 weeks after RYGBP. Our study provides circumstantial evidence for the potential role of ghrelin in the negative energy balance in RYGBP-operated patients.
Obesity Unit, Hospital Clínic Universitari, Villarroel, Barcelona, Spain.
Rosa
R
Morínigo
Roser
R
Casamitjana
Violeta
V
Moizé
Antonio M
AM
Lacy
Salvadora
S
Delgado
Ramon
R
Gomis
Josep
J
Vidal
D000328:Adult; D015992:Body Mass Index; D004435:Eating / Q000502:physiology; D002149:Energy Intake; D004734:Energy Metabolism; D005215:Fasting; D005260:Female; D005502:Food; D015390:Gastric Bypass; D054439:Ghrelin; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000601:surgery*; D036361:Peptide Hormones / Q000097:blood* / Q000502:physiology; D013997:Time Factors; D015431:Weight Loss / Q000502:physiology
D054439:Ghrelin; D007328:Insulin; D036361:Peptide Hormones