Surgeons at Huashan Hospital in Shanghai followed 221 patients who had type 2 diabetes before a sleeve gastrectomy, and found most were still free of diabetes years afterward. They used the data to build a short scoring system meant to estimate, before surgery, how likely a given patient is to end up in that group. The paper was published online on September 12 in Obesity Surgery.
Sleeve gastrectomy removes most of the stomach and leaves a narrow tube. Improvement in type 2 diabetes is one of the main reasons people living with both conditions consider the operation, which makes the question of who keeps that improvement a practical one.
81.4% were in remission at an average of 3.6 years
The team looked back at Chinese patients with obesity and type 2 diabetes who had a first sleeve gastrectomy at the hospital between 2017 and 2023. Follow-up ran from two to seven years, averaging 3.6 years.
Of the 221 patients, 81.4% met the study's definition of diabetes remission. The group's median HbA1c, a blood test reflecting average blood sugar over roughly the previous three months, went from 7.20% before surgery to 5.60% after. A reading below 5.7% is generally considered outside the diabetes range.
That starting figure matters for reading the rest. A median HbA1c of 7.20% describes a group whose diabetes was, on average, moderately controlled rather than severe or long established. Remission rates reported in groups with harder diabetes tend to run lower.
The score rests on diabetes drugs, insulin use and a C-peptide reading
The researchers screened a list of preoperative measurements and narrowed it to three that carried the predictive weight: how many glucose-lowering medicines the patient was taking, whether the patient was on insulin, and the two-hour plasma C-peptide level.
C-peptide is released by the pancreas in step with insulin, so measuring it two hours after a glucose load is a practical way to gauge how much insulin the pancreas can still produce on demand. More of that reserve means more capacity to hold normal blood sugar once surgery reduces the body's insulin resistance.
The direction is intuitive. Needing several drugs, or needing insulin, signals a pancreas further along in losing function. A higher C-peptide signals the opposite.
The combined model reached an AUC of 0.876. AUC measures how well a model separates the two outcomes, where 0.5 is a coin flip and 1.0 is perfect separation, so 0.876 is strong discrimination. An internal check that re-ran the model on 2,000 resampled versions of the same dataset produced a mean AUC of 0.878, with a 95% confidence interval of 0.809 to 0.935.
The model has not been tested outside the hospital that built it
A resampling check of that kind tests whether a model is stable within the data it was built on. It does not test whether the model holds up on different patients at a different hospital. That step, called external validation, has not been done.
Prediction models routinely perform worse the first time they meet an outside population, and this one was built entirely on Chinese patients having one specific operation. Patients having bariatric surgery in the United States tend to differ in body size and in the mix of procedures performed. None of that makes the three predictors wrong. It does mean this particular score should not be used to hand an individual patient a number.
The published abstract does not say what counted as remission
The 81.4% figure rests on a definition the abstract does not state, and the full text sits behind a publisher paywall that blocked an automated read for this article. Definitions in this field vary. Some require an HbA1c under 6.5% with no diabetes medication at all. Others accept a higher threshold, or allow reduced medication. Those choices can move a reported remission rate by a wide margin, so the headline percentage is best read as the authors' figure under their own criteria rather than a number that can be lined up against other studies.
The remaining limits are the usual ones for work of this kind. The study was retrospective, run at a single center, and built on 221 patients, a modest number for developing and testing a model. Anyone weighing sleeve gastrectomy for type 2 diabetes is better served treating these three measures as a frame for a conversation with their surgeon and endocrinologist than as a calculator that settles the question.
Educational information only. This brief is not medical advice. Do not start, stop, or change treatment based on it.
Reporting note
OTN reviewed the linked sources and documents listed above. The article identifies estimates, projections, unresolved questions, and the limits of the evidence.
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