Arthritis Treatment Shows Off-Target Benefits for Those Also Living with Diabetes

A recent study published in BMC Rheumatology has found that a combination therapy could have a benefit for individuals diagnosed with diabetes and ankylosing spondylitis (AS), psoriatic arthritis (PsA), or rheumatoid arthritis (RA). The therapy is a TNF inhibitor called TNF-alpha.


This study compared TNF inhibitors to methotrexate (MTX) to see which would improve HbA1c for patients. Data was received from Clinformatics. This platform includes demographic information for patients, their use of prescription drugs, diagnostics, lab values, and medical history. A total of 13 million are included in this database.

This study focused on the period from 2000 to 2014. Patients who were diagnosed with AS, RA, or PsA as well as diabetes were included. Patients had to have a HbA1c of 7% or higher to be included and had to have received either MTX, metformin, or TNF inhibitors. The metformin group was the control for this study.

Changes in each patients HbA1c after the treatment was started was documented. 10,389 treatments were initiated during the study period for 9,541 patients. In total, 254 TNF-alpha initiations, 361 MTX, and 2,144 metformin were studied. What the researchers found is that both therapies (TNF-alpha and MTX) supported reductions of HbA1c, and that the extent of these reductions were comparable.

TNF-alpha was able to both disrupt insulin signaling and promote insulin resistance. This means that insulin sensitivity overall  could be improved.

After TNF inhibitors the HbA1c median changes were as follows-

  • TNF-alpha: -.35
  • MTX: -.4
  • Metformin: -.8

Metformin decreased HbA1c the furthest, followed by methotrexate, and then TNF inhibitors. In fact, MTC and TNF inhibitors produced half as much of a decrease as did metformin.

This study ultimately shows that treatments for these various inflammatory  diseases do have potential to also improve diabetes outcomes for patients, even though this is off-target for both MTX and TNF inhibitors.

You can read more about this study here.

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