Quit Smoking to Improve Rheumatoid Arthritis
A new study from Sweden suggests that smoking may be linked to a higher risk of radiographic disease progression in patients with early rheumatoid arthritis (RA). The authors also confirmed previously reported predictors.
“Based on our results, clinicians can differentiate patients at high versus low risk of radiographic progression already at diagnosis of RA using three easily accessible parameters: smoking habits, radiographic erosions, and CRP level. This may be practical when choosing treatment strategy in new-onset RA,” said lead author Saedis Saevarsdottir, MD, PhD, Rheumatology Unit, Department of Medicine, Karolinska University Hospital and Karolinska Institute, and Unit for Clinical Therapy Research, Karolinska Institute, Stockholm, Sweden.
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Researchers studied data from the SWEFOT trial including 487 patients (aged ≥18 years) who had experienced RA symptoms for less than 1 year and were not taking disease-modifying antirheumatic drugs took methotrexate, methotrexate plus infliximab, or methotrexate plus sulfasalazine and hydroxychloroquine.
The authors concentrated on 311 participants who had radiographs at baseline and at 1-year follow-up. Of these individuals, 79 experienced radiographic disease progression. Smoking, baseline erosions, erythrocyte sedimentation rate, and C-reactive protein were independent predictors of radiographic progression, and these results were consistent after adjusting for the different treatment regimens.
Three-dimensional risk matrices then determined that 63% of individuals with the predictors of current smoking status, baseline erosions, and CRP developed radiographic progression after 1 year, compared with 12% of patients who did not have these predictors.
A strength of the study, as noted by Saevarsdottir, is the fact that it was part of an investigator-initiated clinical trial that was carried out in an unselected early RA population. In addition, since the trial reflects standard care in Sweden, the validity of the matrix model should be high.
“Furthermore, smoking is a modifiable predictors and the findings highlight the importance of smoking cessation programs in RA,” she added.
While previous research has suggested that individuals with RA who are smokers may develop more radiographic damage over time, “no recent studies on predictors for rapid radiographic progression after 1 year had included smoking habits in their multivariate analyses or risk matrices, in the setting of today’s standard treatment considering all other reported clinical predictors,” said Saevarsdottir.
The study’s potential limitations are its lack of data on smoking intensity (pack-years) and the fact that it was not designed to determine why smoking affects radiographic progression.
In terms of future research, “An important step is to evaluate the effect of smoking cessation programs that have recently been initiated as part of standard care at several clinics in Sweden and abroad, since reports on smoking and treatment response, as well as our data on radiographic progression, show that past smokers do as well as never smokers, thus indicating that smoking cessation is beneficial for this reason too,” she said.
This study is one of two on the effects of smoking that were published in a recent issue of Annals of the Rheumatic Diseases. A second study found that antiphospholipid antibodies (aPL) were positively associated with a history of smoking, especially among former smokers. In addition, researchers observed a strong association between the combination of smoking and aPL with vascular events.
-Meredith Edwards White
Reference
Saevarsdottir S, Rezaei H, Geborek P, et al; for the SWEFOT study group. Current smoking status is a strong predictor of radiographic progression in early rheumatoid arthritis: results from the SWEFOT trial. Ann Rheum Dis. 2014 Apr 4. doi: 10.1136/annrheumdis-2013-204601. [Epub ahead of print]