STRESS HYPERGLYCEMIA VERSUS DIABETES: DIFFERENTIAL IMPACT ON POSTOPERATIVE OUTCOMES IN MAJOR ABDOMINAL SURGERY

Introduction: Major abdominal surgeries are associated with significant morbidity, and preoperative metabolic optimization has emerged as a potentially modifiable determinant of postoperative outcomes. Hyperglycemia and poor long-term glycemic control, commonly assessed through glycated hemoglobin levels, have been linked to impaired immune response, endothelial dysfunction, and altered wound healing in surgical patients. Objective: To systematically evaluate the association between preoperative glycemic control and postoperative complications in adults undergoing major abdominal surgery, and to explore whether specific glycemic thresholds are associated with differential risk across procedure types. Methods: A systematic review was conducted in PubMed, Scopus, Web of Science, Cochrane Library, LILACS, ClinicalTrials.gov, and ICTRP, focusing on studies published in the last five years. Results and Discussion: A total of 14 studies met the inclusion criteria. Most observational cohorts demonstrated that elevated preoperative HbA1c levels were independently associated with increased rates of surgical site infection, anastomotic leak, prolonged length of stay, and 30-day mortality, although heterogeneity in HbA1c thresholds and surgical populations limited direct comparability. Evidence quality ranged from low to moderate, primarily due to observational design and residual confounding. Conclusion: Suboptimal preoperative glycemic control appears to be associated with higher postoperative complication rates following major abdominal surgery. Standardization of HbA1c thresholds and prospective interventional trials are needed to define optimal perioperative glycemic targets.