Loading ...

TOPLINE:

The use of semaglutide and tirzepatide increased over time among patients with rheumatic and musculoskeletal diseases (RMDs). Both treatments were associated with meaningful weight loss at 1 year, with greater reductions seen in tirzepatide users and in people without diabetes.

METHODOLOGY:

• Researchers analyzed data from a rheumatology registry to describe initiation patterns of semaglutide and tirzepatide in patients with RMDs and to identify factors linked to weight loss.
• They included 60,198 adults with RMDs treated in US rheumatology practices between 2018 and 2024 (mean age, 57.0 years; 80.5% women). Patients had a mean BMI of 36.4, and 54.9% had diabetes.
• New users were patients who had a rheumatology visit recorded immediately before their first prescription of semaglutide or tirzepatide; patients without such a prior visit were classified as prevalent users.
• Weight trajectories were examined among 16,481 new users with paired weight measurements.
• The main outcome was the change in body weight from baseline to 12 months of follow-up. Additional outcomes included achieving weight loss of at least 5%, 10%, or 15%.

TAKEAWAY:

• The use of semaglutide and tirzepatide increased from 0.1% in 2018 to 6.8% in 2024. Tirzepatide accounted for about one third of the total use of GLP‑1 receptor agonists by 2024.
• Semaglutide users lost an average of 5.8% of body weight at 12 months, while tirzepatide users lost an average of 8.2%. Adjusted models found 2.2% greater weight loss among tirzepatide users (coefficient, -2.20; 95% CI, -2.4 to -1.9). Patients without diabetes lost 1.8% more weight than those with diabetes (coefficient, -1.80; 95% CI, -2.1 to -1.5).
• Tirzepatide users were nearly 50% more likely to lose at least 5% of body weight than semaglutide users (adjusted odds ratio [aOR], 1.46; 95% CI, 1.36-1.57) and had almost double the odds of losing at least 15% of body weight (aOR, 1.94; 95% CI, 1.77-2.13).
• Women and people with inflammatory arthritis (at specific thresholds) had increased odds of weight loss, whereas Black individuals and those with higher social deprivation had reduced odds.

IN PRACTICE:

“Observing these differences in a large, real-world rheumatology cohort underscores the importance of recognizing that not all GLP-1 RAs [receptor agonists] are equivalent in terms of weight-loss efficacy,” the authors of the study wrote.

SOURCE:

The study was led by Nicholas P. McCormick, Auburn University Harrison College of Pharmacy, Auburn, Alabama. It was published online on May 8, 2026, in ACR Open Rheumatology.

LIMITATIONS:

Researchers could not determine how long patients stayed on treatment or what dose they reached. They might have missed comorbidities treated outside rheumatology. The results may not be generalized beyond rheumatology settings or to populations outside the US.

DISCLOSURES:

The study received support in part from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Three authors reported receiving industry support in the form of grants or contracts, consulting fees, and/or other payments (to themselves or to their institutions).

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