Preoperative Muscle Mass and 1‐Year Diabetes Remission After Metabolic Surgery: Associations Across Remission Definitions

Aims This study aimed to evaluate 1‐year T2DM remission and preoperative factors associated with remission across different outcome definitions following metabolic surgery. Methods This retrospective cohort study included patients with T2DM and a preoperative BMI ≥ 27.5 kg/m 2 who underwent Roux‐en‐Y gastric bypass or sleeve gastrectomy. The primary outcome was consensus‐defined diabetes remission at the assessment closest to 12 months, defined as HbA1c < 6.5% measured ≥ 3 months after discontinuation of all glucose‐lowering medications. Secondary outcomes were stringent biochemical normoglycaemia and remission at all three postoperative assessments. Results Among 70 patients, 56 (80.0%) achieved consensus‐defined remission and 24 (34.3%) achieved stringent biochemical normoglycaemia at 1 year. Shorter diabetes duration was independently associated with consensus‐defined remission (adjusted OR [aOR], 0.24; 95% CI: 0.06–0.65), whereas absolute total muscle mass (TMM) was not (aOR, 1.24; 95% CI: 0.54–2.97). For stringent biochemical normoglycaemia, shorter diabetes duration, higher fasting C‐peptide and greater absolute TMM were independently associated with the outcome. Residualized muscle mass (RMM) was also associated with this outcome in exploratory sensitivity analyses. Adding muscle measures to the ABCD and IMS scores improved cross‐validated discrimination for this stringent outcome. Conclusions Preoperative muscle mass was not associated with consensus‐defined diabetes remission but was associated with stringent biochemical normoglycaemia after metabolic surgery. Adding either absolute TMM or RMM to established remission scores improved cross‐validated discrimination for this stringent outcome; however, these findings remain exploratory and require external validation.