A meta-analysis designed to determine the hierarchies of different bariatric surgeries in patients with obesity and type 2 diabetes mellitus (T2DM), has reported that one anastomosis (mini) gastric bypass (OAGB/MGB) is more likely to achieve diabetes remission compared with other bariatric surgeries. However, biliopancreatic diversion without duodenal switch (BPD) appears to be the most effective surgery for achieving long‐term diabetes remission.
The meta-analysis, ‘Comparative effectiveness of bariatric surgeries in patients with obesity and type 2 diabetes mellitus: A network meta‐analysis of randomized controlled trials’, published in Obesity Reviews, by researchers from Tianjin Medical University General Hospital, Tianjin, China, also found Roux‐en‐Y gastric bypass (RYGBP) is the most favourable alternative to manage cardiometabolic conditions.
The study included 17 randomised controlled trials (RCTs) and compared six bariatric surgeries (OAGB/MGB, BPD, laparoscopic‐adjustable gastric banding (LAGB), laparoscopic sleeve gastrectomy (LSG), RYGBP, greater curvature plication (GCP)) and non-surgical treatments (NST). The 17 RCTs included 1,108 patients who underwent bariatric surgery and/or NST between 2008 and 2018. In summary, the eligibility criteria for inclusion in the meta-analysis were as follows:
Adults (16 years or older) who were overweight or obese with clearly documented T2DM (BMI≥30 or BMI≥25 with at least one obesity‐related comorbidity, including T2DM).
A history of at least one of the listed bariatric procedures, NST or another bariatric surgery
The primary outcomes were complete T2DM remission, defined as HbA1c levels < 6.0% at consecutive annual clinic visits with no use of anti‐hyperglycaemic medications20 or as defined by the individual studies.
Secondary outcomes were cardiometabolic related, including mean changes in weight loss, blood pressure, total cholesterol, triglycerides, low‐density lipoprotein cholesterol (LDL‐C) and high‐density lipoprotein cholesterol (HDL‐C).
The randomized controlled trials (RCTs) were targeted towards adult patients with obesity and T2DM.
Unsurprisingly, the authors reported that OAGB/MGB, BPD, LSG, RYGBP and LAGB were all highly effective vs NST at achieving the remission of diabetes, except for GCP, for the studies with short‐ and long‐term follow‐up. According to the surface under the cumulative ranking curve (SUCRA), the rank probability of remission of diabetes (from best to worst) among bariatric surgeries was: OAGB/MGB (91.2%) > BPD (87.3%) > LSG (61.4%) > RYGBP (59.3%) > LAGB (29.6%) > GCP (18.6%) > NST (2.5%) (Figure 1).
Figure 1: ranking of bariatric surgeries according to primary and secondary outcomes. A, SUCRA value for remission of diabetes (all duration); B, SUCRA value for remission of diabetes (follow‐up > 3 years); C, cumulative SUCRA value after normalization for eight secondary outcomes (0–100). Every bariatric surgery was normalized with points up to a maximum of 12.5 for eight secondary outcomes, including glucose, weight loss, systolic pressure, diastolic pressure, total cholesterol, triglyceride, HDL‐C and LDL‐C, with an overall maximum score of 100. BPD, biliopancreatic diversion without duodenal switch; GCP, greater curvature plication; LAGB, laparoscopic‐adjustable gastric banding; LSG, laparoscopic sleeve gastrectomy; mini‐GBP, single anastomosis (mini) gastric bypass; NST, nonsurgical treatment; RYGBP, Roux‐en‐Y gastric bypass; SUCRA, surface under the cumulative ranking curve.
For those studies with more than three years follow‐up, BPD, OAGB/MGB‐GBP and LSG were significantly superior to NST in achieving the remission of diabetes, except for LAGB. BPD was more effective at achieving remission of diabetes vs with LAGB and LSG. According to the SUCRA, the rank probability of remission of diabetes with follow‐up period of more than three years (from best to worst) among bariatric surgeries: BPD (91.3%) > mini‐GBP (84.2%) > RYGBP (58.4%) > LSG (39.9%) > LAGB (24.9%) > NST (1.2%).
For weight loss, LSG and RYGBP were significantly more effective than NST and RYGBP was superior to NST in lowering glucose levels. RYGBP was superior to LAGB and NST in controlling HDL levels. With regards to other secondary outcomes, including systolic and diastolic pressure, total cholesterol, triglycerides and LDL‐C, there were no significant differences among RYGBP, BPD, LSG, LAGB and NST.
According to the SUCRA, the overall rank of probability for bariatric surgeries (from best to worst) was RYGBP (68.0%) > BPD (65.1%) > LSG (52.3%) > LAGB (43.1%) > NST (21.6%) after comprehensively weighing all secondary outcomes, including glucose levels, weight loss, systolic and diastolic pressure, total cholesterol, triglycerides, HDL‐C and LDL‐C.
“Cardiometabolic outcomes were included in our analysis to provide a ranking of available bariatric surgeries when different cardiometabolic outcomes were taken into consideration. However, no evidence was available to determine the effect of mini‐GBP on cardiometabolic outcomes,” the authors wrote. “The short‐ and long‐term effects of bariatric surgery in the control of diabetes and management of cardiometabolic conditions suggest that the manipulation of the stomach or intestines through surgery, medical devices or drugs may be the most radical change in the treatment of T2DM in the past century.”
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