TOPLINE:

Among patients with type 1 diabetes (T1D) and obesity, metabolic bariatric surgery was associated with significant weight loss, lower insulin requirements, a modest reduction in A1c levels, and favourable changes in lipid profile at 1 year.

METHODOLOGY:

• Researchers conducted a multicentre retrospective cohort study using electronic clinical records to evaluate 1-year effects of metabolic bariatric surgery on weight loss, metabolic control, and insulin requirements in people living with T1D and obesity.
• They analysed 162 patients (median age at surgery, 37.5 years; 77.8% women) who underwent either Roux-en-Y gastric bypass (42.0%) or sleeve gastrectomy (58.0%); the majority (57.4%) used multiple daily injections for insulin delivery.
• Body weight, BMI, and percentage total weight loss were assessed before surgery and monitored up to 15 months afterwards.
• Glycaemic outcomes included A1c levels and the total daily insulin dose; additional metabolic parameters included lipid profile, renal function, and blood pressure.

TAKEAWAY:

• At 12 months, the median percentage total weight loss was 29.7%, and the mean BMI decreased from 40.2 to 28.5 (P < .001).
• The total daily insulin dose decreased from a median of 82.6 to 36.3 units/d, and the weight-adjusted total daily insulin dose fell from a median of 0.75 to 0.32 units/kg/d (P < .001 for both comparisons); greater total weight loss was associated with lower weight-adjusted insulin requirements.
• Median A1c levels decreased from 64.0 to 60.0 mmol/mol at 12 months; moreover, lipid profile and blood pressure improved significantly (P < .001 for all).
• Weight loss, A1c levels, or insulin requirements did not differ significantly between sleeve gastrectomy and Roux‑en‑Y gastric bypass.

IN PRACTICE:

"MBS [metabolic bariatric surgery]provides greater metabolic benefits for those with higher BMI, though surgical risks must be considered. Treatment decisions should be individualized, considering BMI, cardiometabolic risk, patient preference, and expected benefit," the authors wrote.

SOURCE:

This study was led by Rieneke van der Meer, Nederlandse Obesitas Kliniek, Huis ter Heide, Utrecht, Netherlands, and Sofia Pazmino, KU Leuven, Leuven, Belgium. It was published online on February 18, 2026, in Diabetes Care.

LIMITATIONS:

The study was retrospective, which potentially introduced bias. It lacked a non‑surgical control group for direct comparisons. Follow‑up measurements were not standardised, and continuous glucose monitoring or self‑monitored glucose data were not routinely available. Longer-term data and information on postoperative complications, hospitalisations, and key clinical outcomes were not collected consistently.

DISCLOSURES:

This study was funded by the Innovative Medicines Initiative 2 Joint Undertaking, which was supported by the European Union's Horizon 2020 research and innovation programme and the European Federation of Pharmaceutical Industries and Associations, and other sources. The Nederlandse Obesitas Kliniek received funding from Medtronic to conduct the study. One author reported serving or having served on advisory panels and speakers bureaus for multiple pharmaceutical companies, with financial compensation paid to KU Leuven, which also received research funding that supported her work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.