Which Bariatric Surgery Led to Superior Outcomes in Patients With T2D?

Individuals with type 2 diabetes (T2D) who underwent Roux-en-Y gastric bypass (RYGB) exhibited greater weight loss, a slightly higher T2D remission rate, less T2D relapse, and better long-term glycemic control compared with those who had sleeve gastrectomy (SG), according to a study published in JAMA Surgery.

This cohort study included data from 9710 individuals participating in the National Patient-Centered Clinical Research Network Bariatric Study. In total, 6233 patients underwent RYGB and 3477 had SG. Patient outcomes were analyzed up to 5 years following surgery.

“Remission of T2D is common after bariatric surgery and may reduce risk for subsequent microvascular and macrovascular disease,” the authors said.

T2D remission was defined as “the first postsurgical occurrence of an HbA1c [hemoglobin A1c] level less than 6.5% following at least 6 months (presurgical and/or postsurgical time) without T2D medication prescription orders.” In addition, relapse was defined as levels of 6.5% or more and/or a prescription for T2D medication after patient remission.

Participants' mean (SD) preoperative body mass index was 49 (8.4) and most (73%) patients were female.

These study findings are especially noteworthy:

• The RYGB cohort reflected 6.2% to 8.1% more total body weight loss than the SG cohort at each check point, and a 10.2-kg (22.5 lb) difference (95% CI, 8.3-12.1; P&thinsp;<.001) in weight loss was present at 5 years
• Patients who underwent RYGB showed slightly (10%) higher T2D remission rates than those who had SG (HR, 1.10; 95% CI, 1.04-1.16)
• Of 6141 patients eligible for relapse analysis, the relapse rate was lower for RYGB than SG (HR, 0.75; 95% CI, 0.67-0.84)
• After 5 years, HbA1c levels remained 0.80 (95% CI, 0.72-0.88) percentage points below baseline among the RYGB cohort and 0.35 (95% CI, 0.19-0.51) percentage points below baseline among the SG cohort, a difference of 0.45 (95% CI, 0.27-0.62)

The researchers point out that the relapse rate was high in both cohorts within 5 years of initial remission (33% in patients who underwent RYGB and 42% in SG). Some patient subgroups also exhibited lower rates of T2D remission.

“Preoperative insulin use, older age, higher HbA1c level, and more complex T2D medication regimens predispose patients to lower probability of T2D remission,” the researchers note.

In order to make informed decisions about which surgery may be best suited for individual patients, additional studies should investigate adverse event profiles and the efficacy of the procedure compared with other methods of weight management.

However, the authors conclude, “these results indicate that RYGB is associated with better long-term T2D and weight outcomes than SG in real-world clinical settings.”

Reference

McTigue KM, Wellman R, Nauman E, et al. Comparing the 5-year diabetes outcomes of sleeve gastronomy and gastric bypass [published online March 4, 2020]. JAMA Surg. doi: 10.1001/jamasurg.2020.0087.