Effect of Laparoscopic Sleeve Gastrectomy on Static and Dynamic Measures of Glucose Homeostasis and Incretin Hormone Response 4-Years Post-Operatively.

INTRODUCTION: There is limited literature available on the long-term effect of bariatric surgery especially laparoscopic sleeve gastrectomy (LSG) on the incretin hormone response. AIM: Our primary aim was to investigate changes in glucose metabolism and incretin hormone responses in participants with impaired glucose regulation approximately 4 years after LSG. The secondary aim was to examine the long-term incretin hormone changes of biliopancreatic diversion (BPD).
METHOD: A non-randomised prospective study comprising of 10 participants undergoing LSG and 6 participants undergoing BPD. Serial measurements of glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were performed during an oral glucose tolerance test pre-operatively and 1 month, 6 months and at approximately 4-7 years post-operatively. Area under the curve (AUC) was examined at 60 and 120 min.
RESULTS: In the LSG group, a significant reduction in 2-h plasma glucose (2 h PG), HbA1c and HOMA-IR was observed at 4 years. Compared with pre-operative levels, significant increases in post-glucose GLP-1 secretion were observed at 1 and 6 months, but not maintained at 4 years. A linear increase was seen in post-glucose GIP response at 1 month and 6 months and 4 years. Within the BPD group, a reduction in HbA1c along with an increase GLP-1 response was observed at 7 years.
CONCLUSION: An increase in GLP-1 response was not preserved at 4 years, but a significant increase in GIP response was observed along with improved glycaemic control following LSG.