Individuals with rheumatoid arthritis (RA) had an increased risk of hospitalizations from chronic obstructive pulmonary disease (COPD) when compared with the general population in a Canadian retrospective, population-based cohort study.
The risk of COPD hospitalizations was 47% higher in individuals with RA. “This finding emphasizes the need to control inflammation in rheumatoid arthritis, not only to prevent joint damage, but also to prevent complications of systemic inflammation, including the development of comorbidities such as cardiovascular diseases and COPD,” wrote Diane Lacaille, MD, of the University of British Columbia, Vancouver, and her coauthors (Arthritis Care Res. 2017 Oct 19. doi: 10.1002/acr.23410).
Nick Piegari/Frontline Medical News
Dr. Diane Lacaille
Several previous studies have suggested a link between COPD and inflammation, Dr. Lacaille and her colleagues said. Accordingly, they sought to evaluate the risk of COPD hospitalizations in a cohort of 24,625 individuals with RA as compared with 25,396 general population controls randomly selected and matched based on age, sex, and index year. Most subjects in the analysis were female, and the mean age at onset of RA was 57.2 years.
The investigators reported an increased incidence of COPD in individuals with RA, compared with controls, based on an incident rate ratio (IRR) of 1.58 (95% confidence interval, 1.34-1.87) that dropped to 1.47 (95% CI, 1.24-1.74) after adjustment for potential confounders, including comorbidities and health services usage at baseline. The overall incidence rate for COPD was 2.07 per 1,000 patient-years for RA patients and 1.31 per 1,000 patient-years for controls.
When the model was stratified based on sex, COPD hospitalization risk was significantly increased in women (adjusted hazard ratio [HR], 1.61; 95% CI, 1.30-1.98), but not in men (adjusted HR, 1.25; 95% CI, 0.95-1.66), they said.
Data were not available on smoking, the main COPD risk factor, for the patients in this study; however, the increased risk of COPD hospitalizations in the RA group remained significant after modeling for smoking, according to the investigators.
Combined, these results have “notable implications for the clinical care of RA and COPD,” Dr. Lacaille and her coinvestigators said.
Both clinicians and people living with RA “should be aware of the increased risk of developing COPD and be vigilant in watching for early symptoms of COPD, so that appropriate diagnostic tests can be administered at the onset of early symptoms,” they wrote. “Early detection of COPD is essential so that effective treatments can be initiated before irreversible damage to the lungs occurs, to improve long-term outcomes.”
These findings strengthen the conclusions of two previous cross-sectional studies showing an association between RA and COPD prevalence, according to the investigators. In one study, RA patients in Israel who were receiving disease-modifying antirheumatic drugs had double the prevalence of COPD, compared with general population controls, according to authors of that study (Immunol Res. 2013;56[2-3]:261-6). Similarly, U.K. investigators compared 421 RA patients against controls and reported a twofold increase in obstructive pattern on screening spirometry in the RA group (Ann Rheum Dis. 2013;72:1517-23).
The current study from Dr. Lacaille and her coinvestigators was supported by funding from the Canadian Institute for Health Research. The authors reported that they had no financial disclosures, conflicts of interest, or benefits from commercial sources.