Weight loss outcomes and associated factors after metabolic bariatric surgery: analysis of routine clinical data in Scotland

Background
Bariatric surgery is a cornerstone intervention for individuals with severe obesity, offering substantial and sustainable weight loss.

Methods
This retrospective cohort study included 186 patients with obesity and Type2 diabetes who underwent sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) between 2009 and 2020 at University Hospital Ayr. Optimal clinical response weight loss was defined as excess weight loss (%EWL) ≥50% or total weight loss (%TWL) ≥20%.

Results
At 2-years post-surgery, 43.6% achieved ≥50 %EWL, and 44.1% achieved ≥20%TWL, with 31.8% maintaining this at 5-years. Depending on the definition used, between 11.2% and 45.9% of patients experienced recurrent weight gain. BMI had significant positive association with %TWL but negative with %EWL (p<0.05). RYGB had significantly higher %TWL compared to SG (p<0.05).

Conclusion
Most patients experienced weight loss which was maintained over time, however recurrent weight gain was noted. Pre-surgery BMI was significantly associated with weight changes.