Guideline directed care for diabetes calls for control of glycemia, blood pressure and cholesterol (composite goal). Most patients treated medically do not reach this goal.
Determine the efficacy and safety of Roux-en-Y gastric bypass (RYGB) added to lifestyle modification and intensive medical management (LS/IMM) to achieve control of all 3 endpoints.
Two-arm unblinded randomized clinical trial with 120 participants. The primary endpoint of the composite outcome was assessed at 12 months. The study began in April 2008 and completed one year follow-up in all participants in December 2012.
Four academic teaching hospitals in the U.S. and Taiwan, involving five operating surgeons.
Inclusion criteria for the Diabetes Surgery Study (DSS) included HbA1c ≥ 8.0%, BMI 30.0-39.9 kg/m2, diagnosis and treatment of type 2 diabetes for at least six months, and stimulated C peptide > 1.0 ng/ml.
All patients received lifestyle intervention modeled after the Look AHEAD study. Medications for hyperglycemia, hypertension, and dyslipidemia were prescribed according to protocol. RYGB techniques were standardized.
Main Outcome Measure
Attainment of a composite goal: HbA1c < 7.0%, LDL-C < 100 mg/dl, and SBP < 130 mmHg.
One hundred and twenty participants were randomized with equal probability into LS/IMM or RYGB (60 in each group). Baseline characteristics were similar between groups. Mean BMI was 34.6 kg/m2 (95% CI 29.2 to 40.8 kg/m2) with 71 (59%; 95% CI 50% to 68%) participants having BMI < 35 kg/m2, and mean HbA1c was 9.6% (95% CI 9.4% to 9.8%). At 12 months the followup rate was 95%, and 11 (19%) in the LS/IMM group and 28 (49%) in the RYGB group achieved the primary endpoint (OR = 4.8, 95% CI 1.9 to 11.6). RYGB participants required 3.1 fewer medications than LS/IMM (4.8 versus 1.7, 95% CI -3.6 to -2.3). Weight loss was 7.9% LS/IMM vs. 26.1% RYGB (difference 18.2% 95% CI 14.2% to 20.7%). Regression analyses indicate that achieving the composite endpoint was primarily attributable to weight loss. There were 22 serious adverse events in the RYGB group, including one cardiovascular event, and 15 in the LS/IMM group. There were 4 peri-operative complications and 6 late postoperative complications in the RYGB group. Nutritional deficiency of iron, vitamin B12 and albumin were observed more frequently with RYGB.
In mild to moderately obese patients with type 2 diabetes addition of RYGB to LS/IMM resulted in greater likelihood of achieving the composite treatment goal. RYGB participants required fewer medications but had more complications.