“The most over-represented cause of death in this population by far was respiratory-related deaths,” Dr. Mikuls said in a telephone interview. “Patients in this population were about three times more likely than age- and race-matched individuals in the general population to die of respiratory causes.
“It’s easy to say, ‘Well, this is a male cohort, lots of cigarette smokers; it’s all just that.’
“I don’t know that it is,” he added, noting that preliminary results from a health study on nurses suggest similar findings of respiratory deaths also being over-represented in a predominantly female cohort.
“We all take care of patients with lung disease who have rheumatoid arthritis; interstitial lung disease and chronic obstructive lung disease are both over-represented in RA populations.
“I wouldn’t call it shocking” Dr. Mikuls said of the findings, “but it certainly was compelling.”
At 56%, chronic obstructive pulmonary disease was the most common respiratory cause of death and was followed by ILD (22%). Both are known to be over-represented in RA.
Disease Activity
Another important finding, said Dr. Mikuls, is that a lack of disease activity at time of enrollment appeared to tilt in favor of survival. If RA was in remission, mortality risks were not substantially elevated compared with population norms, noted the authors.
In contrast, researchers found that higher disease activity at enrollment was associated with both all-cause and cause-specific mortality, which demonstrates a striking dose-dependent relationship with cardiovascular death, according to the article. Previous studies have shown similar findings, noted Dr. Mikuls.
“It would suggest to me that tight disease control is not only good for joint symptoms and quality of life, but may actually extend survival in patients.”
The findings suggest that it may be possible to prolong survival through intervention, smoking cessation programs and other modification efforts. For example, the results revealed that people who are underweight or on prednisone have higher mortality risk. So a rheumatologist may decide to help a patient make modifications to limit those risks, explained Dr. Mikuls.
“Prednisone use has been associated particularly [with] cardiovascular mortality in other studies, as well,” he said. “We saw it in all-cause mortality; we didn’t quite see a significant relationship for cardiovascular, but we certainly saw it trending in that direction.
“The takeaway being … at least for all-cause mortality, reducing prednisone while maintaining disease control is going to be important.”
Cardiovascular risk associated with RA has received much greater attention in the past decade, with an emphasis on tighter disease control of such risk factors as hypertension, diabetes and dyslipidemia, lead author Bryant R. England, MD, of the Veterans Affairs Medical Center, explained in an email to The Rheumatologist.
