Respiratory-Related Mortality Higher in Men with RA

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A study that found men with rheumatoid arthritis (RA) died from respiratory-related illness nearly three times as often as the general population could provide insight into possible treatment options and lifestyle changes that would help them live longer.

The Study

Researchers at the Veterans Affairs Nebraska-Western Iowa Health Care System and University of Nebraska Medical Center in Omaha, Neb., conducted a longitudinal study using an RA registry that allowed them to follow male veterans from enrollment through death or the year 2013. They used the National Death Index database to obtain vital status and cause of death. They calculated crude mortality rates and standardized mortality ratios for all-cause cardiovascular disease (CVD), cancer and respiratory mortality.

The authors were particularly interested in identifying the causes of death among men who are U.S. veterans who have higher mortality rates attributable to high levels of co-morbidities.

“One of the recurrent themes when you look at all-cause mortality and different causes of death is that there are some things in here that are modifiable,” says Ted R. Mikuls, MD, a co-author of the study and Umbach Professor of Rheumatology at the UNMC Department of Internal Medicine Division of Rheumatology.

Of 1,652 men involved in the study, 332 died over a cumulative follow-up time of 6,141 patient-years. The top three causes were cardiovascular disease at 31.6%, cancer at 22.9% and respiratory disease at 15.1%, according to an article on the study published in Arthritis Care & Research.¹

RA causes inflammation, which is a known risk factor for heart disease, so it was not surprising that results showed CVD contributed to nearly one-third of the deaths.

Most of the patients were white, with an average age of about 65, and had a history of frequent smoking, a high level of co-morbidity, and average disease duration of about 12 years. A majority were seropositive for rheumatoid factor or anti-cyclic citrullinated peptide.

Dr. Mikuls

Several contributing factors were associated with all-cause mortality in this group, such as older age, white race, smoking, low body weight, co-morbid disease activity and use of prednisone. Rheumatoid factor concentration was associated with CVD mortality, as were subcutaneous nodules, which were also associated with respiratory mortality. Use of methotrexate or a biologic agent was not associated with all-cause or cause-specific mortality.

Although advances have been made in treatments for RA patients, they continue to have higher death rates than the general population, the authors note. Standardized mortality ratios for these patients mirror a 30% to 70% hike in mortality risk. Other studies have shown that survival is also reduced among women with RA, but for men the absolute mortality risk appears to be disproportionately higher.