Diabetes status and not preoperative glycemic control is associated with postoperative outcomes in metabolic/bariatric surgery.

Abstract

Background: Elevated hemoglobin A1C (HbA1C) is a surrogate for poor glycemic control, but its association with outcomes in metabolic surgery is not well established with respect to diabetes severity. This study aimed to extend prior evidence and evaluate the influence of preoperative HbA1C on postsurgical outcomes in patients undergoing primary laparoscopic sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB), hypothesizing that poor glycemic control and/or worse diabetes severity would lead to increased postoperative complications.

Objectives: Identify the association of HbA1C or diabetes status on postoperative complications.

Setting: Metabolic and Bariatric Surgery Accreditation Quality Improvement Project (MBSAQIP) database (2017-2022).

Methods: Primary SG and RYGB cases were analyzed in patients with diabetes (n = 106,486), identified by a known diagnosis or preoperative HbA1C ≥ 6.5%. Multivariate logistic regression models with generalized estimating equations were used to assess the effects of preoperative HbA1C on clinical outcomes, controlling for demographics, procedure type, and co-morbidities.

Results: Similar to smaller studies, no significant association was found between preoperative HbA1C levels and clinical outcomes for SG or RYGB. In contrast, subset analysis revealed increased odds ratios (ORs) for serious complications in both noninsulin-using (OR: 1.04, 95% confidence interval [CI]: 1.00-1.09) and insulin-using (OR: 1.07, 95% CI: 1.03-1.12) patients with diabetes. Insulin-using diabetes was also associated with an increased risk of infectious complications (OR: 1.05, 95% CI: 1.01-1.10). Stratification by procedure type showed that the association was significant only for RYGB (OR: 1.08, 95% CI: 1.02-1.14).

Conclusions: Increased preoperative HbA1C levels are not associated with increased risk for complications overall; however, higher HbA1C in patients with insulin-using diabetes, which is suggestive of more advanced disease, is associated with an increased risk of serious and infectious complications following RYGB. While preoperative glycemic control does not lead to poor outcomes, this study demonstrates that patients with more severe diabetes do have slightly higher risk of complications but that risk is not modifiable and intrinsic to their chronic disease status.