Effect of HbA1c and Inflammatory Hematological Markers on Postoperative Outcomes in Diabetic Patients Undergoing Major Abdominal Surgery

Background Diabetic patients undergoing major abdominal surgery are at increased risk of postoperative complications due to chronic hyperglycemia and altered inflammatory responses. Glycated hemoglobin (HbA1c) reflects long-term glycemic control, while complete blood count-derived inflammatory markers provide insight into systemic inflammation. This study evaluated the association of HbA1c and inflammatory hematological markers with postoperative outcomes in diabetic patients undergoing major abdominal surgery. Methods This prospective observational cohort study was conducted at Nawaz Sharif Medical College and Aziz Bhatti Shaheed Teaching Hospital, Gujrat, Pakistan, over a 12-month period from February 2024 to January 2025. Adult diabetic patients undergoing elective or emergency major abdominal surgery were enrolled using consecutive sampling. Preoperative HbA1c and inflammatory hematological parameters, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR), were assessed. Postoperative complications occurring during hospitalization or within 30 days were recorded. Multivariable logistic regression was performed to identify independent predictors of postoperative complications. Results A total of 205 patients were included in the final analysis. The mean age was 58.6 ± 9.8 years, and 57.6% were male patients. Overall, 77 patients (37.6%) developed postoperative complications. Patients with complications had significantly higher mean HbA1c levels compared with those without complications (8.8 ± 1.3% vs. 7.6 ± 1.2%, p < 0.001). Inflammatory markers, including total leukocyte count, neutrophil count, NLR, and PLR, were significantly elevated, whereas LMR was significantly lower in the complication group (all p < 0.001). On multivariable analysis, HbA1c (adjusted OR 1.42, 95% CI 1.18-1.72), NLR (adjusted OR 1.31, 95% CI 1.18-1.46), and PLR (adjusted OR 1.08, 95% CI 1.03-1.14) were independently associated with postoperative complications. Conclusion Elevated HbA1c and inflammatory hematological markers are independently associated with adverse postoperative outcomes in diabetic patients undergoing major abdominal surgery. These readily available parameters may aid in preoperative risk stratification and perioperative optimization.