Weight Regain After Gastric Bypass: Influence of Gut Hormones

The Roux-en-Y gastric bypass (RYGB) is the gold standard bariatric operation. However, a major concern in late follow-up is the substantial weight regain. Understanding the role of gastrointestinal hormone secretion in this situation is relevant.

The aim of the present study was to evaluate the influence of gastrointestinal hormones comparing postprandial secretion of ghrelin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1), and leptin between patients with weight regain and those with favorable weight control. Twenty-four patients with follow-up from 27 to 59 months were divided into two groups according to sustained weight loss: group A (14 patients) had sustained weight losses, and group B (10 patients) had significant weight regain. Basal serum levels of ghrelin, GIP, GLP-1, and leptin after fasting and 30, 60, 90, and 120 min after a standard meal were measured.

There was no difference in the ghrelin secretion. There was a difference in the GIP secretion, with a higher percentage increase in 30 min in group A (330% × 192.2%; p = 0.01). There were also differences in the GLP-1 secretion, with higher increases in absolute (p = 0.03) and percentage values after 30 min in group A (124% × 46.5%; p = 0.01). There was also a difference between baseline leptin values, with higher levels in group B (p = 0.02).

The secretion of gut hormones in patients with weight regain after RYGB is different from that in patients with satisfactory weight outcome. After meal stimulation, reduced levels of GIP and GLP-1 may indicate the influence of gut hormones in the process of weight regain.