BOSTON – A diagnosis of rheumatoid arthritis doubled the risk of death from any cause over the risk for those without RA, based on 34 years of follow-up data from women in the Nurses’ Health Study.
Incident RA was associated with a 40% increase in the risk of death, and seropositive RA was associated with a 51% increase in the risk of death, Dr. Jeffrey A. Sparks of Brigham and Women’s Hospital, Boston, reported at the annual meeting of the American College of Rheumatology.
Dr. Jeffrey A. Sparks
The data also revealed a much stronger link between RA and the risk of death due to respiratory causes. That rate was sixfold higher in seropositive women with RA. While there is an appreciation of an increased risk for cardiovascular disease and cancer in RA patients, deaths due to respiratory disease are “an underappreciated cause of death” that warrant more focus in these patients, he said.
Among the 25,699 deaths that took place during the course of the study, 261 of them occurred in the 960 women who developed RA after they enrolled in the study. Among the women with RA, cancer was the cause of death in 29%, cardiovascular disease in 22%, and respiratory causes in 16%.
The study allows direct comparisons of RA patients and controls over a prolonged time with detailed data on clinical, lifestyle, and serologic factors, he said. Compared with women without RA, all-cause mortality was significantly higher in women with RA after adjustment for age and other potentially confounding factors (hazard ratio, 2.07; 95% CI, 1.83-2.35).
The variables used to adjust the analyses were age, questionnaire period, U.S. region, race/ethnicity, education, husband’s education, body mass index (<18.5, 18.5-24.9, 25-29.9, ≥30 kg/m2), cigarette smoking pack-years (never, 0-10, 10.1-20, >20), postmenopausal hormone use, physical activity, healthy eating index, cancer, cardiovascular disease, diabetes, family history of diabetes, family history of cancer, family history of myocardial infarction before age 60 years, and aspirin use. Modifiable factors were adjusted up to RA diagnosis (cigarette smoking pack-years, physical activity, and BMI).
The mortality rate was higher for women with seropositive disease than it was for those without RA (HR, 2.33; 95% CI, 2.00-2.71), as was the rate for seronegative RA (HR, 1.60; 95% CI, 1.30-1.98).
For every 5 years of RA duration, mortality risk increased 32% (95% CI, 27%-36%) compared with unaffected women. Women with RA had significantly increased risks for mortality from CVD (HR, 1.87; 95% CI, 1.44-2.43), cancer (HR, 1.35; 95% CI, 1.07-1.69), and respiratory causes (HR, 4.50; 95% CI, 3.28-6.17), compared with women without the disease.
Respiratory mortality for women with seropositive RA was sixfold higher than it was for non-RA women (HR, 6.23; 95% CI, 4.38-8.85). Among women with RA, there were 43 respiratory deaths caused by pneumonia (11), emphysema (8), chronic interstitial lung disease (5), asthma (1), and other respiratory diseases (18).
Dr. Sparks had no relevant financial disclosures. The National Institutes of Health and the Rheumatology Research Foundation funded the study.