Long-Term Weight Loss and Metabolic Outcomes After Bariatric Surgery in a Large Asian Cohort: A Real-World Cohort Study

BACKGROUND: Metabolic-bariatric surgery (MBS) is the most effective treatment for obesity and its associated metabolic complications. Long-term real-world outcome data from Asian populations remain limited, particularly for procedural comparisons and longitudinal metabolic trajectories.

OBJECTIVE: To evaluate weight loss outcomes, metabolic outcomes, and clinical predictors of treatment response following bariatric surgery in a large Asian cohort, with longitudinal follow-up up to five years in a selected subgroup of completers.

METHODS: This retrospective cohort study analyzed 1,478 adult patients who underwent primary bariatric surgery (laparoscopic sleeve gastrectomy [LSG], Roux-en-Y gastric bypass [RYGB], or one-anastomosis gastric bypass [OAGB]) between 2012 and 2022 at a single tertiary academic center in Malaysia. The primary outcome was percentage total weight loss (%TWL) at 1, 3, and 5 years, analyzed using an available-case approach. Pre-specified attrition analysis compared the characteristics of 5-year completers with non-completers. Secondary outcomes included longitudinal changes in glycated hemoglobin (HbA1c), blood pressure, and LDL cholesterol, with paired and cross-sectional analyses reported separately. Glycaemic outcome thresholds (HbA1c