Background: Bariatric surgery in obese subjects can result in remission of type 2 diabetes (T2D) at some future point post-surgery. The aim of our observational prospective single-centre study was to examine glycaemic patterns in adult T2D candidates for bariatric surgery using a continuous glucose monitoring (CGM) sensor for 14 days after surgery to search for indicators predictive of T2D remission 1 year later.

Methods: Patients underwent CGM preoperatively and for 14 days postoperatively. Thereafter, body weight and glycated haemoglobin (HbA1c) levels were monitored at 3, 6 and 12 months after surgery.

Results: A total of 31 patients (mean age 47 ± 2 years) were analyzed. After surgery, mean interstitial glucose levels fell rapidly from 157 ± 31 mg/dL preoperatively to 109 ± 35 mg/dL postoperatively (P < 0.001), reaching nadir levels from day 3 after surgery. Successful bariatric surgery (loss of excess weight ≥ 50%) was observed in 28 (90%) patients, and diabetes remission (HbA1c ≥ 6.0% with no antidiabetic treatment) 1 year after surgery was noted in 21 (68%) patients. CGM for 14 days post-surgery allowed prediction of diabetes remission 1 year after surgery: time spent above range < 14% and standard deviation (SD) of glucose levels < 33 mg/dL were both strong predictors of T2D remission. Indeed, the association of these two criteria predicted diabetes remission with a 100% positive predictive value, 81% sensitivity and 100% specificity and, when combined with the advanced Diabetes Remission (Ad-DiaRem) score, further increased predictive accuracy.

Conclusion: The use of 14-day postoperative CGM recordings together with presurgical clinical scores can help to predict diabetes remission 1 year after bariatric surgery.