Association between preoperative carbohydrate loading and intraoperative glucose levels in patients undergoing pancreatoduodenectomy: a single-center retrospective study

Introduction: This study aimed to investigate intraoperative glucose control during pancreatoduodenectomy to clarify the uncertain effect of recommended preoperative carbohydrate loading. Method: In this retrospective study, patients undergoing pancreatoduodenectomy between July 2022 and July 2025 were divided into three groups according to the dose of preoperative carbohydrate loading: control (no loading), 25 g, and 50 g. Patients with ≥3 intraoperative blood glucose measurements were included. Primary outcome was the intraoperative time-weighted average (TWA) blood glucose levels. Secondary outcomes were postoperative changes in HbA1c and insulin resistance, mean blood glucose levels postoperatively, and clinical outcomes. Perioperative blood glucose levels were compared using the Kruskal-Wallis test followed by Dunn's post hoc analysis with Holm adjustment. Result: A total of 625 patients were analyzed (control: 350; carbohydrate 25 g: 200; carbohydrate 50 g: 75), and 35.4% had preoperative diabetes. Baseline characteristics were comparable between groups. Intraoperative TWA blood glucose levels of carbohydrate 50 g group were significantly lower than both control group (P < 0.001) and 25 g group (P = 0.018) in post hoc analysis (control: median [IQR] 160.7 [140.1, 177.1] vs. 25 g: 153.6 [138.6, 174.9] vs. 50 g: 146.3 [127.6, 165.5] mg/dL). Mean blood glucose levels during the first 12 postoperative hours and changes in HbA1c were also significantly lower in the 50 g group than other two groups. Changes in insulin resistance were comparable across groups. Conclusion: Preoperative carbohydrate loading was associated with improved perioperative glycemic control during pancreatoduodenectomy. Further prospective studies are required to confirm these results.