Early-phase insulin hypersecretion associated with weight loss outcome after LSG: a prospective cohort study in Asian patients with BMI ≥28 kg/m2.

ABSTRACT

BACKGROUND: Obesity has become a global problem that poses a serious threat to human health. Laparoscopic sleeve gastrectomy (LSG) is an effective long-term treatment. However, the weight loss of some patients after LSG is still insufficient. It is necessary to investigate the factors associated with inadequate weight loss after LSG. OBJECTIVE: The objective of this study was to explore whether preoperative insulin secretion could be associated with weight loss after LSG in patients with obesity. SETTING: This is a single-center prospective cohort study conducted in a university hospital. METHODS: Patients from a prospective database who underwent LSG were analyzed. All 178 participants underwent a 75-g oral glucose tolerance test (OGTT) to assess preoperative insulin and c-peptide secretion before LSG. The areas under the curve (AUCs) for glucose, insulin, and c-peptide were determined in the OGTT. The percentage of excess weight loss (%EWL) and the percentage of total weight loss (%TWL) were used to estimate the effect of weight loss after LSG. Regression models were used to assess the correlation between preoperative insulin and c-peptide secretion with %EWL ≥75% and TWL ≥35% at 12 months after LSG. RESULTS: The AUCs of insulin and c-peptide were significantly lower in the %EWL ≥75% and %TWL ≥35% groups at 0-30 minutes, 0-60 minutes, and 0-120 minutes during the OGTT. At 30, 60, and 120 minutes during the OGTT, c-peptide levels were significantly lower in the %EWL ≥75% group and %TWL ≥35% group. The preoperative c-peptide level at 30 minutes during the OGTT (C30) was significantly negatively correlated with %EWL (ß = -.37, P < .001) and %TWL (ß = -.28, P = .011). Univariate logistic regression analysis showed that preoperative C30 was associated with %EWL ≥75% and %TWL ≥35% after LSG. According to multiple logistic regression analysis, patients with a low preoperative C30 had an 8-fold higher %TWL ≥35% after LSG than those with a high C30 (odds ratio 8.41 [95% confidence interval 1.46-48.58], P = .017). Similarly, patients with a low preoperative C30 had a 7-fold higher EWL% ≥75% after LSG than patients with a high C30 (odds ratio 7.25 [95% confidence interval 1.11-47.50], P = .039). CONCLUSIONS: The rate of weight loss after LSG is low among patients with preoperative hyperinsulinemia. The preoperative c-peptide level at 30 minutes during the OGTT is associated with weight loss after LSG.