Table 1.
Randomized controlled trials that directly compared the effectiveness of bariatric procedures with medical management for the treatment of type 2 diabetes
| Trial | Dixon et al[57] | Schauer et al[34] | Mingrone et al[105] | Ikramuddin et al[58] |
| Intervention arms | LAGB; standard medical management | RYGB; LSG; medical management | RYGB; BPD; medical management | RYGB with medical management; medical management |
| Follow-up duration (yr) | 2 | 1 | 2 | 1 |
| Baseline characteristics | ||||
| n | 60 | 150 | 60 | 120 |
| Mean BMI (kg/m2) | 37 (30-40) | 36 (27-43) | 45 (35-60) | 34 (30-40) |
| Duration of T2DM (yr) | < 2 | > 8 | 6 | 9 |
| Mean HbA1c | 7.8% | 9.2% | 8.7% | 9.6% |
| Primary end-point | FBG < 126 mg/dL with HbA1c < 6.2% without pharmacotherapy | HbA1c < 6% with or without pharmacotherapy | FBG < 100 mg/dL with HbA1c < 6.5% without pharmacotherapy | CV risk reduction with HbA1c < 7% with LDL cholesterol < 100 mg/dL and systolic BP < 130 mmHg |
| End results | ||||
| Diabetes remission | LAGB 73%; medical arm 13% | RYGB 42%; LSG 37%; medical arm 12% | BPD 95%; RYGB 75%; medical arm 0% | RYGB 75%; medical arm 32% |
| Mean HbA1c | LAGB 6.0%; medical arm 7.2% | RYGB 6.4%; LSG 6.6%; medical arm 7.5% | BPD 4.9%; RYGB 6.3%; medical arm 7.7% | RYGB 6.3%; medical arm 7.8% |
| Mean BMI (kg/m2) | LAGB 29.5; medical arm 36.6 | RYGB 26.8; LSG 27.2; medical arm 34.4 | BPD 29.1; RYGB 29.3; medical arm 43.1 | RYGB 25.8 medical arm 31.6 |
| Mean excess weight loss | LAGB 62%; medical arm 4.3% | RYGB 88%; LSG 81%; medical arm 13% | BPD 69%; RYGB 68%; medical arm 9% | 1RYGB 26.1 medical arm 7.9% |
| Major surgical complications | 2 revision surgeries (6.7%) due to pouch enlargement; 1 required band removal due to persistent regurgitation | 4 re-operations (4.0%) due to intra-abdominal hematoma, vomiting, cholecystectomy, and feeding access after gastric leak | 2 re-operations (5.0%) due to incisional hernia and bowel obstruction. More nutritional risk in BPD than in RYGB | 2 re-operations (3.3%) due to anastomotic leak. Surgical group had 50% more serious events with greater nutritional deficiency than medical arm |
| Mortality | Nil | Nil | Nil | Nil |
| Comment | This trial involved patients with early (< 2 yr) diabetes of mild severity (HbA1c < 7.8%), but only 22% of patients had BMI 30-35. This trial supported early surgical intervention for early obese T2DM | This trial involved patients with more advanced diabetes (> 8 years and HbA1c 9.2%), with 34% of patients having BMI < 35. This trial supported surgical intervention in more severe T2DM | This trial involved severely obese diabetic patients and showed the greater effectiveness of bariatric surgery over medical therapy in poorly controlled T2DM | This trial showed the potential benefits and risks of adding RYGB to the best medical therapy in achieving therapeutic goals for diabetes (49% vs 19%). This trial had a higher proportion of BMI 30-35 (59%) |
1
Mean weight loss. T2DM: Type 2 diabetes mellitus; BMI: Body mass index; LAGB: Laparoscopic adjusted gastric banding; RYGB: Roux-en-Y gastric bypass; LSG: Laparoscopic sleeve gastrectomy; BPD: Bilio-pancreatic diversion; FBG: Fasting blood glucose; HbA1c: Glycosylated hemoglobin; LDL: Low density lipoprotein; CV: Cardiovascular.