Risk Factors Linked to ILD Identified Among Patients With RA

Older age at rheumatoid arthritis (RA) onset, higher body mass index (BMI), oral glucocorticoid use, and smoking history are associated with the presence of interstitial lung disease (ILD) among patients with RA, according to study results published in Arthritis Research & Therapy.

Interstitial lung disease is known to be one of the most common extra-articular manifestations of RA, with both conditions associated with significant morbidity and mortality.

The aim of the study was to assess the clinical characteristics of patients with RA-ILD vs those with RA without ILD.

Researchers established a cohort including patients with RA-ILD. They collected data from this cohort between May 2017 and March 2021. Measures included functional disability, quality of life, and lung function.

The researchers used multivariable logistic regression to identify factors correlated with ILD in patients with RA, including the age of disease onset, BMI, smoking history, oral glucocorticoid use, and methotrexate. Researchers also collected demographic information such as age, education, and income.

Analyses compared the health measures of patients in the RA-ILD group with those who had RA without ILD (RA-non-ILD). Participants underwent follow-up examinations every 2 years.

Patients in the RA-ILD group (N=148) had a mean age of 65.8 years and included 35.8% men; those in the RA-non-ILD group (N=410) had a mean age of 58.0 years and included 14.6% men.

The RA-ILD vs RA-non-ILD group had a higher percentage (43.9% vs 14.2%, P <.001) of late-onset RA, which occurred at 60 years and older. Higher age at RA onset (odds ratio [OR], 1.056, 95% CI, 1.021–1.091), higher BMI (OR, 1.65; 95% CI, 1.036-2.629), smoking history (OR, 2.484; 95% CI, 1.071-5.764) and oral glucocorticoid use (OR, 3.562; 95% CI, 2.160-5.874) were all associated with ILD in patients with RA. Methotrexate use was less likely to be correlated with ILD (OR, 0.253; 95% CI, 0.155-0.412).

Study limitations included the cross-sectional design that did not allow for causal links between clinical factors and ILD to be established.

Physicians treating patients with RA should monitor for the potential development of ILD, as well as educate patients on the risk factors associated with ILD in RA.

Disclosure: One study author declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of author’s disclosures.