Effect of Gastric Bypass on Spontaneous Growth Hormone and Ghrelin Release Profiles

• Published in: Obesity (Silver Spring, Md.) Vol. 14; no. 3; pp. 383 - 387
• Main Authors: Mancini, Marcio C., Costa, Ana P.A.C., Melo, Maria Edna, Cercato, Cintia, Giannella‐Neto, Daniel, Garrido, Arthur B., Rosberg, Sten, Albertsson‐Wikland, Kerstin, Villares, Sandra M.F., Halpern, Alfredo
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.03.2006
• Subjects: Adult; Body Composition; Body Weight - physiology; Female; Gastric Bypass; Ghrelin; growth hormone; Growth Hormone - blood; Growth Hormone - secretion; hormone profile; Humans; Insulin Resistance - physiology; Longitudinal Studies; Middle Aged; Obesity - blood; Obesity - physiopathology; Obesity - surgery; Peptide Hormones - blood; Peptide Hormones - secretion; Postprandial Period - physiology; Prospective Studies; Roux‐en‐Y gastric bypass; severe obesity
• ISSN: 1930-7381; 1930-739X
• DOI: 10.1038/oby.2006.51

Objective: The purpose of this study was to analyze growth hormone (GH) concentrations in obese women before and after Roux‐en‐Y gastric bypass (RYGBP) and how resulting changes in weight, fat mass, ghrelin levels, and insulin sensitivity affect GH secretion. Research Methods and Procedures: Blood was sampled at 20‐minute intervals for 24 hours in 10 non‐diabetic premenopausal severely obese women before and 6 months after RYGBP. GH concentrations were measured in all samples, and serum ghrelin was collected at five time‐points. Results: After a 27% BMI drop (55.9 ± 6.2 to 40.7 ± 5.8 kg/m2), blunted GH profiles underwent partial recovery. Basal, postprandial, and mean ghrelin concentrations were not changed. A negative correlation was found between mean GH levels and insulin and homeostasis model assessment (p < 0.01). BMI accounted for 54% of GH variation. Discussion: Partial recovery of GH secretion after RYGBP‐induced weight loss suggests that a blunted secretion is not a causal factor of obesity but a consequence of the obese state and does not seem to be ghrelin‐level dependent.