Background

Obesity is a strong independent risk factor for numerous comorbidities including diabetes type II. Elevated hemoglobin A1c is a predictor in postoperative outcomes. We sought to investigate the impact of preoperative levels of HbA1c on the efficacy and outcomes of bariatric surgery.

Methods

A retrospective study was conducted in our hospital from 2012 to 2019, identifying patients that underwent a sleeve gastrectomy or Roux-en-Y bypass, and then separated into controlled (HbA1c <=6), elevated (HbA1c <6 to <= 8.5) and super-elevated (HbA1c >8.5) groups. Analysis using R was performed to find significant differences up to 1 year post-op.

Results

557 patients were identified: 348 in the controlled group (mean HbA1c 5.5), 175 in the elevated group (HbA1c 6.7), and 34 in the super-elevated group (HbA1c 9.2). By 1 year, all groups achieved a mean HbA1c of <7. The controlled group achieved more significant improvements in blood pressure and triglyceride levels, while the super-elevated group showed less significant improvements in HDL. 30-day complication rates were similar amongst all groups, including readmission, reoperation, and surgical site infection. Only the elevated group demonstrated higher rates of urinary retention (p<0.05). Length of stay was significantly different (p<0.001) but clinically similar (2 vs. 2.5 vs 2.4 days).

Conclusions

Patients with higher pre-operative HbA1c levels experience a similar benefit from bariatric surgery without higher complication rates as those with controlled levels.