Patients with rheumatoid arthritis are two times more likely to have concurrent chronic obstructive pulmonary disease (COPD) than healthy controls -- an association which was sustained even when variables such as age, gender, smoking and obesity were controlled for, according to a study presented today at the EULAR 2011 Annual Congress.
The study of 15,766 patients with RA and 15,340 controls found that the prevalence of COPD was significantly higher in RA patients than healthy controls (8.9% vs 4.4%, p<0.001). Interestingly, the link was still significant (p<0.001) after risk factors common in both RA and COPD patients, such as smoking, obesity and socioeconomic status, were controlled for.
"We know that similar changes in core physiological processes cause symptoms in RA and COPD and we hope that the results of our study prompts new research into potential links between altered genetic and autoimmune processes in the two conditions" said Dr. Amital of the Sheba Medical Centre, Israel.
The large, population-based case-control study was performed using the patient database of Israel's largest healthcare provider, Clalit Health Services. The prevalence of COPD was compared between RA patients over 20 years of age and a sample of age- and gender-matched patients without RA (the control group). Group matching was performed and data on health-related lifestyles and other co-morbidities was collected. Multivariate logistic regression models were used to compare study groups and to control for the confounders of age, gender, socioeconomic status, smoking and obesity.