Comparison of Meal Pattern and Postprandial Glucose Response in Duodenal Switch and Gastric Bypass Patients

Bariatric surgery improves glucose homeostasis; however, side effects such as hypoglycemia can occur. We investigated the effects of meals on interstitial glucose (IG) response in biliopancreatic diversion with duodenal switch (BPD-DS) and Roux-en-Y gastric bypass (RYGBP)-operated patients at least 1 year after surgery.

Thirty patients treated with BPD-DS or RYGBP were recruited at the outpatient Obesity Unit, Uppsala University Hospital. IG was measured by continuous glucose monitoring (CGM) for 3 consecutive days, and postprandial IG levels from 5 to 120 min were analyzed for 2 of these days. All intake of food and beverages was simultaneously registered in a food diary, which was processed using The Meal Pattern Questionnaire.

Postprandial IG levels were significantly lower in BPD-DS (n = 14) compared to RYGBP (n = 15)-treated patients, with mean concentrations of 5.0 (± 1.0) and 6.3 (± 1.8) mmol/L respectively (p < 0.001). The mean postprandial IG increment was lower in BPD-DS than in RYGBP patients, 0.2 (± 0.6) vs. 0.4 (± 1.4) mmol/L (p < 0.001). Furthermore, the postprandial IG variability was less pronounced in BPD-DS than in RYGBP patients. The mean number of daily meals did not differ between the two groups, 7.8 (± 2.6) in BPD-DS and 7.2 (± 1.7) in the RYGBP (p = 0.56).

BPD-DS patients demonstrated lower postprandial IG concentrations, with smaller postprandial IG increments and less pronounced postprandial IG variability compared to RYGBP patients. The two groups had similar meal pattern and the postprandial IG responses is probably associated with differences in postoperative physiology.