Abstract
BACKGROUND Ghrelin and obestatin are derived from the same gene but have different effects: Ghrelin stimulates appetite, and previous-albeit inconsistent-data show that obestatin may be involved in satiety. The present study was designed to test the hypothesis that Roux-en-Y gastric bypass (RYGB) surgery and/or the weight loss that reliably results from this procedure would alter levels of ghrelin and obestatin and ghrelin/obestatin ratios in a cohort of morbidly obese women. METHODS This is a longitudinal follow-up study in 18 morbidly obese women (mean weight 131.2 kg, mean body mass index [BMI] 47.4). Clinical parameters and fasting serum concentrations of ghrelin, obestatin, triglycerides, low-density lipoprotein cholesterol, glucose, and insulin were measured before and 2 years after RYGB surgery, which was associated with body weight reductions of 41.5 +/- 11.6 kg (mean 62.5% excess weight loss). RESULTS Ghrelin concentrations (-12%, p = 0.022) and ghrelin/obestatin ratios (-14%, p = 0.017) were lower after surgery than before, while obestatin levels did not change. Changes in ghrelin concentrations correlated with changes in insulin levels (r = 0.45, p = 0.011). Most cardiovascular risk factors studied improved postsurgically (p < 0.01). CONCLUSION In contrast to previous weight loss studies involving gastric banding, ghrelin levels decreased and obestatin levels remained stable after massive weight loss in long-term follow-up. The favorable gastrointestinal hormone profiles observed are likely to contribute to the long-term weight loss success rate attributed to RYGB.
