Glycated Hemoglobin as a Predictor of Postoperative Outcomes after Elective Colorectal Surgery

BACKGROUND: Diabetes mellitus has been associated with poor outcomes following elective colorectal surgery. The use of preoperative glycated hemoglobin may provide a more precise estimate of glycemic control. OBJECTIVE: To determine whether glycemic control, using preoperative glycated hemoglobin values, could risk-stratify postoperative outcomes. DESIGN: Observational retrospective cohort study. SETTINGS: Multicenter study including North American centers that contribute towards the National Surgical Quality Improvement Program of the American College of Surgeons dataset. PATIENTS: Adult patients who underwent an elective colectomy or proctectomy for neoplasia or diverticular disease between 2021 and 2023. INTERVENTIONS: The primary exposure was glycemic control, categorized according to diabetes mellitus status and glycated hemoglobin as "no diabetes mellitus," "well-controlled diabetes mellitus," and "poorly controlled diabetes mellitus." MAIN OUTCOME MEASURES: Ten 30-day postoperative outcomes were evaluated and were defined according to the online National Surgical Quality Improvement Program surgical risk calculator. The co-primary outcomes included serious complications, any complication, cardiac complications, and surgical site infection. RESULTS: In total, 32,578 patients were retained for analysis: 19,261 (59.1%) had no diabetes mellitus, 8,999 (27.6%) had well-controlled diabetes mellitus, and 4,318 (13.3%) had poorly controlled diabetes mellitus. On multivariable logistic regression, compared to those with no diabetes mellitus, those with well-controlled diabetes mellitus had a similar risk of any complication (OR 1.04; 95% CI: 0.96-1.12), serious complications (OR 1.03; 95% CI: 0.95-1.12), cardiac complications (OR 1.22; 95% CI: 0.93-1.59), and surgical site infection (OR 0.97; 95% CI: 0.87-1.07). In contrast, compared to patients with no diabetes mellitus, those with poorly-controlled diabetes mellitus had a higher odds of any complication (OR 1.23; 95% CI: 1.12-1.35), serious complications (OR 1.20; 95% CI: 1.08-1.33), and surgical site infection (OR 1.21; 95% CI: 1.06-1.37), but not cardiac complications (OR 1.27; 95% CI: 0.90-1.76). LIMITATIONS: Observational study design, limited to covariates within the National Surgical Quality Improvement Program dataset. CONCLUSIONS: In patients who underwent elective colorectal surgery, glycemic control based on preoperative glycated hemoglobin levels improved postoperative risk stratification compared to diabetes mellitus status alone. See Video Abstract.