Background

Bariatric surgery has been performed as a treatment option for uncontrolled type 2 diabetes. However, the effect of bariatric surgery on insulin secretion has not been well understood. We performed metabolomics study to characterize metabolite profiles for predicting the change of insulin secretion in the early postoperative period following bariatric surgery.

Methods

We enrolled 10 patients with type 2 diabetes consecutively who already participated in STARDOM-PET trial (registration number, NCT03821961). Insulin secretion was measured using Insulinogenic Index (IGI) at preoperative and 3 months after bariatric surgery. Through systematic review of scientific literature, we selected 24 metabolites [including branched-chain amino acids (BCAAs), and products of tryptophan and tyrosine metabolism] which have been known to be associated with diabetes and glucose regulation. Targeted metabolomics was performed using HPLC-Triple quadrupole MS approach, and hierarchical clustering and multivariate analysis were used to identify potential metabolites for predicting the change of insulin secretion after bariatric surgery.

Results

The mean age and baseline BMI of the participants were 49.5 years (SD, 10.1 years) and 36.9 kg/m2 (SD, 3.8 kg/m2), respectively. Mean IGIs at baseline and 3 months after bariatric surgery were 0.45 (SD, 0.86) and 0.93 (SD, 1.16), respectively. The level of BCAAs (leucine, isoleucine, and valine) was significantly lower in patients undergoing a decrease of insulin secretion after bariatric surgery. A higher proportion of aromatic amino acids among large neutral amino acids (LNAAs) was significantly associated with the decrease of insulin secretion after bariatric surgery.

Conclusions

The current study suggested LNAAs profiles could predict the change of insulin secretion in the early postoperative period following bariatric surgery.