Lower Diabetes Risk Among Patients With RA Treated With Combination Therapy or Biologics

Patients with rheumatoid arthritis (RA) are at lower risk of developing diabetes when treated with combination therapy or biologics compared with methotrexate (MTX) monotherapy, according to study results published in RMD Open.

Researchers conducted a cohort study using data from the Chang Gung Research Database to investigate the risk for diabetes among patients with RA treated with disease-modifying anti-rheumatic drugs (DMARDs).

A total of 5530 adult patients with RA but without diabetes were included in the analysis. The main study endpoint was identification of new cases of diabetes, defined as a hemoglobin A1c value of 7% or higher during the follow-up period, from RA diagnosis to the day of diabetes diagnosis.

The follow-up period was divided into monthly intervals, which were further categorized based on the type of treatment received: MTX monotherapy, any biological DMARDs (bDMARDs), MTX in combination with other medications, other conventional DMARDs (cDMARDs), or non-DMARDs.

Out of the 5530 patients with RA, 9.9% were diagnosed with diabetes between 2001 and 2018 (mean follow-up period, 9.2 years).

The risk of developing diabetes was found to be lower during treatment with bDMARDs (hazard ratio [HR], 0.51; 95% CI, 0.32-0.83), MTX combination therapy (HR, 0.50; 95% CI, 0.32-0.78), and other cDMARDs (HR, 0.56; 95% CI, 0.37-0.84) than during treatment with MTX monotherapy.

Individual drug analysis revealed hydroxychloroquine was associated with decreased risk of developing diabetes (HR, 0.52; 95% CI, 0.42-0.65), while tumor necrosis factor-alpha inhibitors (HR, 0.69; 95% CI, 0.46-1.03) appeared to have protective effects.

Further analysis based on other demographic/clinical factors revealed that advanced age (HR, 1.02; 95% CI, 1.01-1.03), male sex (HR, 1.33; 95% CI, 1.04-1.70), hypertension (HR, 1.89; 95% CI, 1.55-2.31), hyperlipidemia (HR, 2.09; 95% CI, 1.42-3.06), and infection with hepatitis C virus (HR, 1.35; 95% CI, 1.02-1.79) were associated with increased risk of developing diabetes.

This study was limited by potential missing data during patient treatment in other hospitals. Additionally, the retrospective nature of the study prevents reporting of current disease activity. Finally, the sample size of patients treated with bDMARDs is small.

The study authors concluded, “Since cardiovascular events are the main cause of morbidity in RA, early selection of appropriate drugs to avoid [diabetes mellitus] development, such as bDMARDs or combination therapy with cDMARDs, should be considered.”