Clinical value of preoperative oral carbohydrate loading in patients with diabetes: a cross-sectional study

Preoperative oral carbohydrate loading (POCL) has shown benefits in non-diabetic patients, but its use in patients with diabetes remains controversial. Concerns about potential hyperglycemia and adverse outcomes have led to conflicting evidence and varied clinical practices. To assess the impact of POCL on clinical outcomes after surgery in patients with diabetes. This retrospective study analyzed 679 patients with diabetes undergoing elective surgery from 2020 to 2023, divided into POCL and fasting groups. After 1:1 propensity score matching (PSM), 410 patients were analyzed. Primary outcomes included postoperative blood glucose levels; secondary outcomes were including glycemic variability, pulmonary infections, hospital stay length, and costs. After PSM, POCL was associated with significantly lower blood glucose levels on the first postoperative day compared to the fasting group (11.03 [9.43–12.77] vs. 11.37 [9.77–13.20], P = 0.045). No significant differences were observed in glycemic variability. POCL patients demonstrated shorter postoperative hospital stays (5.10 [3.00-7.70] vs. 5.90 [3.80–8.50], P = 0.022). Multivariate analysis revealed that POCL independently predicted reduced hospitalization costs (β=-3417.49, 95% CI [-6358.52, -476.46], P = 0.023) and shorter hospital stays (β=-1.21, 95% CI [-1.83, -0.60], P < 0.001). Higher ASA scores and longer surgical durations were associated with increased costs, while prolonged surgeries correlated with greater pulmonary infection risk (OR = 1.005, 95% CI [1.003–1.008], P < 0.001). Despite previous concerns, POCL appears to be associated with lower early postoperative blood glucose levels, shorter hospital stays, and reduced costs in patients with well-controlled diabetes (HbA1c < 7.5%). It may be a safe and effective perioperative strategy for this specific population, though individualized assessment remains essential.