Ghrelin and Obestatin Levels in Severely Obese Women Before and After Weight Loss After Roux-en-Y Gastric Bypass Surgery

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. C.L. Roth and T. Reinehr contributed equally to this work.