Recruiting

Checking blood sugar accuracy in arthritis patients on sulfasalazine

Plain-English translation of NCT07416656 on ClinicalTrials.gov ↗ · Source last updated June 2026 · Translation generated July 2026 · How we translate trials

What is this trial?

Researchers are investigating whether a common blood test called HbA1c accurately measures blood sugar in people taking sulfasalazine for inflammatory arthritis. Sulfasalazine can affect red blood cells in a way that may make this test give misleading results, potentially hiding diabetes or making existing diabetes appear better controlled than it actually is. This study will compare the standard blood test with a continuous glucose monitor (a small sensor that tracks real blood sugar continuously) to see how well they match up.

The medication can cause changes in red blood cells that lower HbA1c readings independently of actual blood sugar levels. This means some patients may be developing diabetes without it being caught, or people with known diabetes may not get treatment intensified when they should, because the blood test looks falsely reassuring.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have been taking sulfasalazine for at least 2 months before joining
you have been diagnosed with inflammatory arthritis (such as rheumatoid arthritis or psoriatic arthritis)
you either have a known diabetes diagnosis or have a borderline blood sugar test result (HbA1c ≥38 mmol/mol) measured at least 2 months after starting sulfasalazine
you speak and understand Danish
you are willing to wear a glucose monitor and allow your data to be uploaded to a secure platform

You likely don't qualify if…

you have taken steroids (by mouth or injection) in the past 2 months or plan to take them in the next 4 weeks
you have other medical conditions that could affect blood test results (besides the expected effect of sulfasalazine on red blood cells)
you are allergic to adhesive tape or medical adhesives used in glucose monitors
you lack decision-making capacity, have active cancer, or have a terminal illness

What participation looks like

You will wear a small glucose monitor sensor (similar to a continuous glucose monitor) for up to 14 days. During this same time period, you will have blood drawn once to measure fasting glucose and HbA1c. The glucose monitor is blinded, meaning you won't see your readings in real time. After the 14 days, researchers will compare what the monitor recorded with your blood test results to see how accurately the blood test reflects your true glucose levels.

AI-generated summary from trial data · Jul 7, 2026 · Not medical advice

Trial locations(1 site)

Denmark

Medical Diagnostic Center, Silkeborg, Central Jutland