In an Australian tertiary-hospital cohort of adults with obesity and type 2 diabetes who underwent metabolic bariatric surgery between 2018 and 2024, complete remission (HbA1c <6.0% at 12 months) occurred in 66.7% of those with baseline BMI ≥50 kg/m² versus 37.8% of those below 50. After adjusting for baseline diabetes duration and HbA1c, the difference disappeared. The BMI ≥50 group lost more total kilograms but achieved lower percent excess weight loss; neither BMI tier nor %EWL independently predicted remission.
The practical lesson is that a very high BMI should not make clinicians or patients pessimistic about diabetes outcomes after surgery. The unadjusted advantage most likely reflects that people reaching BMI ≥50 were, on average, earlier in their diabetes course, with lower HbA1c and shorter disease duration, rather than any metabolic benefit of extreme adiposity. This fits a larger body of work, including DiRECT and long-term surgical cohorts, showing that preserved beta-cell function is the strongest determinant of remission. Surgery works best when pancreatic reserve remains. The authors' call for early referral follows logically, though the design cannot prove it. Limits are real: a single centre, a modest sample (the confidence interval is wide), a 12-month horizon, and observational data prone to residual confounding. Remission also tends to erode over several years, so durability remains unanswered. Confirmatory rather than paradigm-shifting, but a useful counterweight to the assumption that more severe obesity means more refractory diabetes. Adults with type 2 diabetes and severe obesity may reasonably discuss surgical options sooner rather than later.