French National Authority for Health assessment of metabolic surgery for type 2 diabetes remission-A meta-analysis in patients with class I to III obesity

Objective: Randomized controlled trials (RCTs) have demonstrated the superiority of metabolic surgery (MS) over medical therapy (MT) in patients with obesity and type 2 diabetes, leading, to a joint statement in 2016 proposing MS to patients with class I obesity and uncontrolled glycemia. Yet, these RCTs included few patients with class I obesity (body mass index 30-35 kg/m²) and even fewer patients with overweight. Our aim was to provide an updated systematic review (SR) with meta-analysis (MA) of RCTs reporting diabetes remission (DR) after MS in these patients.

Research design and methods: We included in the SR with MA only RCTs with at least 24-month follow-up found in Medline, Cochrane Library, Embase, and LiSSA between January 2008 and September 2022 comparing DR post-MT versus post-MS. We calculated relative risk (RR) and 95 % confidence intervals (CIs) using the Mantel-Haenszel random-effects approach to examine differences in DR between patients allocated to MS versus MT.

Results: DR was significantly higher in MS versus MT after 36 months' follow-up in patients with obesity (RR = 6.65 [95 %CI 2.24;19.79]; I² = 27 %; 5 trials, 404 patients), but also specifically in patients with class I obesity (RR = 5.27 [1.31;21.23]; I² = 0 %; 4 trials, 80 patients). Furthermore, and in line with previous results, all additional MAs performed in patients with obesity in this work favor MS (specifically Roux-en-Y gastric bypass) over MT at 24, 36 (only) and 60 months of follow-up.

Conclusions: Although the data available in patients with class I obesity and type 2 diabetes remains limited, MA shows higher rates of DR after MS compared with MT after 36 months' follow-up in these patients. Consequently, the French National Authority for Health French (HAS) recommends MS for these patients.