Current treatments mainly focus on easing symptoms and lowering inflammation, depending on the specific type of arthritis. Now, researchers at Aarhus University's Department of Biomedicine have identified a possible new direction for future therapies involving GLP-1, the hormone targeted by popular weight loss medications such as Wegovy.

The findings were published in Lancet Rheumatology.

"Our study shows that the body's own GLP-1 hormone is present only in very small amounts in the joints. This means that its natural effect in the joint is likely to be limited. However, it also suggests that GLP-1-based medication, which is administered in much higher doses, may be able to influence inflammation directly in the joints," said Associate Professor Tue Wenzel Kragstrup, who led the research.

Because GLP-1 medications deliver much higher levels of the hormone than the body naturally produces in the joints, researchers believe these drugs could potentially affect inflammation in those tissues.

Possible Double Benefit From GLP-1 Drugs

Weight management is already recommended for many arthritis patients, especially those with osteoarthritis. According to the researchers, GLP-1 medications could eventually provide benefits beyond weight reduction alone.

"Weight loss is already part of the recommendations for many patients with arthritis, but our study may indicate that medication such as Wegovy could have a dual effect -- both through weight loss and by increasing GLP-1 levels in the joints," Kragstrup said.

The study analyzed blood samples and joint fluid taken from arthritis patients. The data work was led by medical doctor and PhD student Mads Brüner together with PhD student Amalie Broksø.

Researchers found that GLP-1 levels inside the joints closely matched levels circulating in the bloodstream.

"We can see that the levels of GLP-1 in joint fluid are closely linked to the levels in the blood. This suggests that it is primarily the amount of GLP-1 circulating in the body that determines how much reaches the joint," Brüner explained.

First Detection of GLP-1 in Arthritic Joint Fluid

Earlier studies had suggested GLP-1 might have anti-inflammatory properties, but this marks the first time scientists have detected the hormone directly in the joint fluid of arthritis patients.

"Our findings provide a biological basis for investigating whether GLP-1-based medication may have direct effects in the joints -- beyond the known effects on weight and metabolism. However, we have not demonstrated that the treatment works against arthritis. This will require a number of clinical studies," Kragstrup said.

The researchers caution that patients should not expect GLP-1 drugs to become arthritis treatments anytime soon. Much more research is needed before doctors can determine whether these medications can actually reduce inflammation or relieve symptoms inside the joints.

"The next step is to investigate whether the medication reaches the joints in sufficient quantities and actually reduces inflammation in the joints."

About the Study

The research was a translational clinical biomarker study that examined paired blood and joint fluid samples from patients with inflammatory arthritis, including rheumatoid arthritis and spondyloarthritis. The goal was to determine whether GLP-1 could be measured in joint fluid and how those levels compared with concentrations found in the blood.

The project involved researchers from Aarhus University's Department of Biomedicine, the Department of Molecular Medicine (MOMA) at Aarhus University Hospital, the Clinic for Rheumatic and Connective Tissue Diseases at the Medical Diagnostic Centre at Hospitalsenhed Midt, the Novo Nordisk Foundation Center for Basic Metabolic Research, and the Department of Biomedical Sciences at the University of Copenhagen.

Funding came from Director Michael Hermann Nielsen's Memorial Grant and the Risford Foundation. The authors reported no conflicts of interest related to the study.