Changes in gut hormone profile and glucose homeostasis after laparoscopic sleeve gastrectomy

Changes in glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) levels after bariatric surgery have been proposed as a mechanism for long-term maintenance of weight loss and improvement in glucose homeostasis postoperatively. The objective of the present study was to assess the changes in GLP-1, PYY, insulin, and glucose levels after laparoscopic sleeve gastrectomy (SG).

Ten morbidly obese patients without type 2 diabetes (3 male, 7 female; body mass index [BMI] 47.92±2.06 kg/m(2)) were evaluated preoperatively and at 6 weeks, 6 months, and 12 months after SG. Total GLP-1, total PYY, insulin, and glucose were measured in fasting state and every 30 minutes after ingestion of 75 g glucose for a total time of 120 minutes.

BMI decreased markedly postoperatively (P<.001). Postprandial total GLP-1 and total PYY responses, measured by the area under the curve (AUC), were significantly increased by the sixth postoperative week compared with preoperative period (P<.001). Fasting insulin levels were markedly decreased postoperatively at all time points (all P<.01). Insulin AUC decreased progressively throughout the first postoperative year (P = .04), whereas glucose AUC decreased significantly at 6 and 12 months postoperatively (both P<.01). Insulin sensitivity measured by the Matsuda index increased progressively postoperatively. First phase insulin secretion remained unchanged.

Postprandial total GLP-1 and total PYY levels increased significantly at 6 weeks post-SG and remained elevated for at least 1 year. These findings may indicate their involvement in better glucose homeostasis and weight loss maintenance after SG.