Metabolic Surgery for Diabetes Treatment: Sleeve Gastrectomy or Gastric Bypass?

Bariatric surgery has gained reputation for its metabolic effect and is increasingly being performed to treat type 2 diabetes mellitus (T2DM). However, there is still a gray area regarding the choice of surgical procedure according to patient characteristics due to inadequate evidences, so far. We aim to compare the efficacy of two most commonly performed bariatric/metabolic surgeries, sleeve gastrectomy (SG) and gastric bypass (GB) with regard to remission of T2DM after surgery.

Outcomes of 579 (349 female and 230 male) patients who had undergone SG (109) or GB (470) for the treatment of T2DM with 1-year follow-up were assessed. The remission of T2DM after SG or GB surgery was evaluated in matched groups using the ABCD scoring system. The ABCD score is composed of the age, BMI, C-peptide levels and duration of T2DM (years).

The weight loss of the SG patient at 1 year after surgery was similar to the GB patients [26.3 (1.1) vs. 32.6 (1.2) %; p = 0.258]. The mean BMI decreased from 35.7 (7.2) to 28.3 (3.7) Kg/m² in SG patients at 1 year after surgery and decreased from 36.9 (7.2) to 26.7 (4.5) Kg/m² in the GB patients. The mean HbA1c decreased from 8.8 to 6.1 % of the SG group and from 8.6 to 5.9 % of the GB group. Sixty-one (56.0 %) patients of the SG group and 300 (63.8 %) of the GB group achieved complete remission of T2DM (HbA1c < 6.0 %) at 1 year after surgery without statistical difference. However, GB exhibited significantly better glycemic control than the SG surgery in groups stratified by different ABCD score. At 5 year after surgery, GB had a better remission of T2DM than SG (53.1 vs. 35.3 %; p = 0.055).

In conclusion, although both SG and GB are effective metabolic surgery, GB carries a higher power on T2DM remission than SG. ABCD score is useful in T2DM patient classification and selection for different procedures.