Poor glycemic control in bariatric patients: a reason to delay or a reason to proceed?

Background: More than 90% of patients with type 2 diabetes (T2D) have obesity, and over 85% of diabetic patients who undergo metabolic and bariatric surgery (MBS) will see improvement or resolution of diabetes. However, diabetes is a known risk factor for surgical complications.

Objectives: To determine whether poor preoperative glycemic control confers an increased perioperative risk after MBS.

Setting: Academic Hospital.

Methods: Retrospective review of data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP). From the 2017-2018 MBSAQIP databases, we identified patients with diabetes who underwent Roux-en-Y gastric bypass or gastric sleeve surgery. Unmatched and propensity-matched univariate analyses, as well as multivariate logistic regressions, were performed to compare 30-day postoperative outcomes and complication rates between patients with poor (glycated hemoglobin [HbA1C] > 7.0) and good (HbA1C ≤ 7.0) glycemic control.

Results: Of 40,132 T2D patients, 19,094 (52.42%) had an HbA1C level ≤ 7.0. Patients with poor glycemic control had slightly higher rates of overall morbidity (6.53% versus 5.49%, respectively; relative risk = 1.188; P < .001). However, in a 1:1 matched analysis of 23,930 patients controlling for body mass index, surgery type, approach, and co-morbidities, the findings of poorer outcomes were largely mitigated. In a multivariate analysis, poor glycemic control was not associated with morbidity.

Conclusions: In T2D patients, poor glycemic control does not independently increase the risk of 30-day morbidity following MBS. Adverse outcomes in the setting of poor glycemic control appear to be largely mediated by associated co-morbidities. Performing MBS in the setting of suboptimal glycemic control may be justified, with the understanding that delaying or refusing surgery can contribute to worsening of diabetes-related co-morbidities that, in turn, may ultimately have a more deleterious effect on outcomes.