Preoperative oral carbohydrate loading and postoperative glucose and insulin metabolism in patients undergoing open abdominal aortic aneurysm repair: A secondary analysis of a randomized controlled trial

Background The role of preoperative oral carbohydrate loading (OCHL) in optimizing postoperative metabolic outcomes in major vascular surgery remains unclear. This secondary analysis of a randomized controlled trial was conducted to evaluate the effects of OCHL on perioperative glucose‐insulin metabolism and patient‐reported well‐being following elective open abdominal aortic aneurysm repair. Methods Patients undergoing elective open aortic repair due to abdominal aortic aneurysm were randomized to receive OCHL (800 mL the evening before, and 400 mL 2 h before anesthesia induction) or standard overnight fasting. Plasma glucose and insulin concentrations were measured at four predefined perioperative time points, and indices of insulin resistance and sensitivity were calculated. Subjective well‐being (anxiety, hunger, thirst, tiredness, pain, and headache) was evaluated using visual analog scales at three perioperative time points. Results Forty patients completed the study. On postoperative Day 1, insulin levels were significantly lower in the OCHL group compared with controls (median [IQR]: 55.3 [44.4] vs. 90.6 [73.1] pmol/L; p = 0.026). Homeostatic model assessment for insulin resistance was significantly lower (12.65 [13.48] vs. 25.56 [19.64]; p = 0.021), and insulin sensitivity index significantly higher (0.079 [0.068] vs. 0.039 [0.046]; p = 0.021) in OCHL patients. Patients receiving OCHL reported lower levels of hunger (1.25 vs. 4.35; p = 0.013), pain (0.8 vs. 3.85; p = 0.011), and fatigue (0.45 vs. 3.3; p = 0.005) compared with controls. Conclusion Preoperative OCHL seems to be a safe nutritional strategy in patients undergoing open aortic repair, with benefits including improved initial glycemic control and enhanced patient well‐being. Further studies are warranted to clarify the role of preoperative OCHL in optimizing metabolic outcomes in vascular surgery.