A comparison of mid- to long-term diabetic outcomes between laparoscopic gastric bypass and sleeve gastrectomy in type 2 insulin-dependent diabetes

Bariatric surgery has been shown to improve glycemic outcomes in patients with obesity and diabetes. Patients requiring insulin indicate advanced disease. Surgery selection for patients with type 2 diabetes requiring insulin therapy (T2-IDM) and obesity is not clear. The purpose of this study is to compare glycemic outcomes between gastric bypass (GB) and sleeve gastrectomy (SG) in T2-IDM patients.

A retrospective review of 52 patients with T2-IDM and obesity undergoing either GB or SG was conducted. Outcomes included target of A1C < 7%, insulin dependency, and remission.

Follow-up ranged from 2 to 8 years. There was no difference in the preoperative duration of diabetes, A1C level, and insulin requirement between GB and SG. GB was associated with greater weight loss at 1 year (30.1% total weight loss) compared to SG (24.7%). There was a significant difference in A1C level at postoperative year 2 favoring the GB group (6.9% vs. 8.04%). GB was associated with a 72% reduction in the hazard of obtaining a postoperative A1C above 7% (HR: 0.28, 95% CI: 0.10–0.78; p = 0.015). GB was associated with an over eightfold reduction in long-acting insulin requirements compared to SG (coefficient: −8.35, 95% CI: −15.6 to −1.12; p = 0.025). Of those reaching A1C < 6.5% in the postoperative period, after adjusting for age, body mass index (BMI), and preoperative A1C, patients who underwent GB had a ~58% decreased hazard of relapsing.

In patients with type 2 diabetes requiring insulin therapy, GB may offer improved glycemic outcomes compared to SG. Larger studies with longer follow-up are needed to address this clinical problem.