Summary: In this 26-week double-blind randomised trial of 72 adults with type 1 diabetes and obesity already using automated insulin delivery (AID), once-weekly semaglutide up to 1 mg, added on top of AID, was compared with placebo. A composite of time in range above 70%, time below range under 4%, and at least 5% weight loss was achieved by 36% on semaglutide versus 0% on placebo (between-group difference 36 percentage points; 95% CI 20.6 to 52.2; P<0.001), with a least-squares mean weight change of -8.8 kg (95% CI -10.6 to -7.0).
PICO Summary
| Element | Detail |
|---|---|
| Population | 72 adults with type 1 diabetes and a body mass index of 30 or higher, all using an automated insulin delivery system; multicentre double-blind randomised controlled trial (United States; ADJUST-T1D, NCT05537233). |
| Intervention | Once-weekly subcutaneous semaglutide titrated up to 1 mg, added to ongoing automated insulin delivery, for 26 weeks (n=36). |
| Comparison | Matching once-weekly placebo added to ongoing automated insulin delivery (n=36). |
| Outcome | Primary composite (continuous glucose monitoring time in range 70 to 180 mg/dl above 70%, time below 70 mg/dl under 4%, and weight reduction of at least 5%): 36% vs 0%; between-group difference 36 percentage points (95% CI 20.6 to 52.2; P<0.001). Least-squares mean between-group differences at week 26: HbA1c -0.3 percentage points (95% CI -0.6 to -0.05); time in range +8.8 percentage points (95% CI 3.9 to 13.7); body weight -8.8 kg (95% CI -10.6 to -7.0). Safety: two severe hypoglycaemia events occurred in each group, and no diabetic ketoacidosis was reported. Absolute risk reduction and number needed to treat for the composite are not directly reported. |
Semaglutide added to AID in type 1 diabetes and obesity
RCT · type 1 diabetes + obesity · 26 weeks
Once-weekly semaglutide added to automated insulin delivery let 36% of adults with type 1 diabetes and obesity reach a strict glucose-and-weight target versus 0% on placebo, with 8.8 kg weight loss. Proof-of-concept only; semaglutide stays off-label in type 1 diabetes.
Expert Commentary
This trial provides the first randomised, placebo-controlled evidence that once-weekly semaglutide, layered on top of automated insulin delivery, can improve a stringent combined glycaemic-and-weight target in adults with type 1 diabetes and obesity. The verdict is cautiously positive: the composite was met by 36% on active treatment and by none on placebo, and the 8.8 kg weight reduction is clinically meaningful in a group for whom obesity is increasingly common. The double-blind design and the funding by a non-profit foundation rather than the manufacturer lend credibility, and reassuringly no diabetic ketoacidosis was observed and severe hypoglycaemia was balanced between arms, although these are exactly the events a 72-patient trial is underpowered to characterise. The principal limitation is scale and duration: with only 36 patients per arm over 26 weeks, this is a proof-of-concept rather than a definitive efficacy study, and the wide confidence interval around the composite difference reflects that fragility. Can I use this with my patients? Not yet as routine care; semaglutide remains off-label in type 1 diabetes, and these data are best reserved for shared decision-making in selected, carefully monitored adults with obesity who are already on automated insulin delivery and counselled about gastrointestinal effects and ketoacidosis vigilance. Larger and longer trials with hard endpoints are needed before this becomes standard practice.
References
Shah VN, Akturk HK, Kruger D, Ahmann A, Bhargava A, Bakoyannis G, Pyle L, Snell-Bergeon JK. Semaglutide in Adults with Type 1 Diabetes and Obesity. NEJM Evid. 2025;4(8):EVIDoa2500173. doi:10.1056/EVIDoa2500173
