In 70 Korean adults with type 2 diabetes and BMI ≥27.5 who underwent gastric bypass or sleeve gastrectomy, 80% met consensus remission (HbA1c <6.5% off all glucose-lowering drugs for ≥3 months), but only 34.3% reached stringent biochemical normoglycaemia at one year. Shorter diabetes duration predicted consensus remission (aOR 0.24); absolute total muscle mass did not (aOR 1.24). For the stringent outcome, shorter duration, higher fasting C-peptide and greater muscle mass all contributed, and adding muscle measures to the ABCD and IMS scores improved cross-validated discrimination.
The central lesson is that the answer to "does muscle matter?" depends on how remission is defined. The consensus threshold is lenient, and 80% of patients clear it, which leaves little variation for any predictor except disease duration to explain. The stringent endpoint better captures true metabolic recovery, and muscle, the body's largest glucose disposal site, plausibly contributes to it. Duration and C-peptide, markers of surviving beta-cell function, again emerge as the dominant drivers, consistent with larger bariatric cohorts. Limits are serious: 70 patients, a retrospective single-centre design, few events for multivariable modelling, and authors who label the muscle findings exploratory. The results remain unvalidated and do not justify changing surgical eligibility. Practically, they reinforce that earlier surgery yields better odds, and that preserving muscle through resistance training and adequate protein is a reasonable, though unproven, strategy around surgery. Incremental and hypothesis-generating.