Poor glycemic control linked to worse outcomes after general surgery

medwireNews: Elevated glycated hemoglobin (HbA1c) is associated with a significantly increased risk for postoperative complications, readmissions, and mortality among patients undergoing general surgery, particularly those having abdominal operations, research shows. 

Gabriel Hundeshagen (University of Heidelberg, Ludwigshafen, Germany) and co-investigators say their findings “support routine preoperative HbA1c screening and the adoption of individualized glycemic management strategies to optimize surgical risk assessment, reduce complications, and improve perioperative outcomes.” 

They analyzed data for 282,131 adults (mean age 60 years, 56% women) who underwent general surgical procedures and were registered in the American College of Surgeons National Surgical Quality Improvement Program from 2021 to 2023. Of these, 36% had been diagnosed with diabetes prior to surgery, and 6.4%, or 10.0% of patients without a documented diabetes diagnosis, had HbA1c values in the diabetes range (HbA1c ≥6.4%; 47 mmol/mol). 

The researchers report in JAMA Surgery that the risk for any complication (surgical, medical, reoperation, readmission, or death) within 30 days of surgery was significantly higher among the patients with diagnosed diabetes relative to healthy controls, and the risk increased with HbA1c level after adjusting for a raft of preoperative and baseline clinical variables. 

Specifically, the odds ratio (OR) for any complication was a significant 1.05 among individuals with diabetes and good glycemic control (HbA1c 7.0–7.9%; 53–63 mmol/mol), 1.16 among those with suboptimal control (8.0–8.9%; 64–74 mmol/mol]), and 1.32 among people with very poor glycemic control (>9%; ≥75 mmol/mol). Participants with diabetes and near-normal glycemia (<6%; <42 mmol/mol) also had a significantly increased risk (OR=1.06), but those with very good glycemic control did not (6.0–6.9%; 42–52 mmol/mol). 

The risk for surgical complications, such as superficial or deep incisional infections, organ-space infections, wound dehiscence, and bleeding requiring transfusion, were significantly elevated among people with diabetes and near-normal (OR=1.10) or very poor (OR=1.15) glycemia versus healthy controls. 

Medical complications, including pneumonia, unplanned intubation, pulmonary embolism, prolonged ventilator use (>48 hours), acute kidney failure, urinary tract infection, stroke, myocardial infarction, and sepsis, were more likely in patients diagnosed with diabetes who had suboptimal (OR=1.15) or very poor (OR=1.43) glycemic control than in healthy controls. 

In addition, patients with diabetes who had good, suboptimal, and very poor glycemic control were significantly more likely to be readmitted than healthy controls, at ORs of 1.09, 1.17, and 1.28, respectively. 

Of note, patients with undiagnosed diabetes were significantly more likely to experience medical complications (OR=1.11) or die (OR=1.24) than those without diabetes but were not at increased risk for other outcomes. 

Subgroup analyses on the 10 most frequent operations within the cohort showed that individuals undergoing gastric surgeries had a similar trend of increased complication risk with diabetes and worsening glycemic control to that of the overall cohort. By contrast, partial mastectomy or laparoscopic repair of an initial inguinal hernia showed no significant associations between complications and glycemic status. 

“The present study highlights a crucial, yet underexplored, aspect of perioperative risk stratification in [general surgery]: the influence of both diagnosed and undiagnosed dysglycemia on postoperative outcomes,” write Hundeshagen and co-authors.  

They conclude: “Integrating glycemic assessment into standard surgical-risk stratification could enable early identification, individualized optimization, and improved outcomes for the broad surgical population.” 

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JAMA Surg 2025; doi:10.1001/jamasurg.2025.4706