Bariatric Surgery Outcomes in Asians with Severe Obesity (BMI ≥ 50 kg/m²)

Background: The benefits of metabolic bariatric surgery (MBS) in people with a body mass index (BMI) ≥ 50 kg/m² are not well-established, with concerns of increased risk and poorer weight loss. The optimal surgical type (gastric bypass [GB] versus sleeve gastrectomy [SG]) is unclear, with studies comparing complication rates, weight loss, and glycaemic outcomes reporting mixed results. Methods: Participants with a BMI ≥ 50 kg/m² undergoing MBS (SG or GB) from 2008 to 2022 were recruited. Demographics, anthropometrics, biochemistry, and diabetes status were analysed at baseline, 12 months, and 24 months post-operatively. Surgical outcomes and complications were analysed. Results: The study included n = 184, with BMI ≥ 50 kg/m² (57.6% female, age 38.6 ± 10.5 years, and BMI 55.3 ± 6.0 kg/m²). Pre-operatively, 21.1% had pre-diabetes, and 33.2% had diabetes (mean HbA1c 8.0 ± 1.7%). Most subjects (89.1%) underwent SG. The overall 30-day adverse event rate was 4.9%, with a higher, but not statistically significant, rate in the GB group (15.0% vs 3.7%, p = 0.061). The GB group had a longer length of stay (GB =4.5 ± 0.6 days, SG = 3.1 ± 0.2, and p = 0.023). The rate of revisional surgery was 2.7%, with no significant difference between groups. The follow-up rate was 67.9% at 12 months and 51.1% at 24 months. The average %total weight loss (%TWL) at 12 months (27.4 ± 9.0%, SG = 27.6 ± 9.0%, GB = 26.0 ± 9.4%, and p = 0.481) and 24 months (27.1 ± 10.9%, SG = 27.4 ± 11.1%, GB = 24.9 ± 8.9%, and p = 0.495) were similar between groups. The GB group had a larger HbA1c reduction (3.2 ± 1.1%) than SG (1.9 ±1.3%, p = 0.030) but no difference in diabetes remission rates (69.2% at 12 months, 76.7% at 24 months). Conclusions: MBS is safe and effective for individuals with a BMI ≥ 50 kg/m², with low complication rates and good weight loss and glycaemic outcomes at 2 years. No statistically significant differences in %TWL, diabetes remission, or complication rates were noted between SG and GB groups, though results are limited by the small number of participants who underwent GB.