Smoking has been known as a risk factor for lung cancer & cardiovascular diseases for many years. However, recently it is being increasingly recognized that it has a role to play in causation & progression of Rheumatoid arthritis (RA).
It was found in the nineties that normal individuals who smoked were four times more likely to have high titer of rheumatoid factor as compared to non smokers. Later, Wolfe & colleagues showed that not only were the smokers more likely to have a positive Rheumatoid factor; but the titers also correlated with the duration of smoking. The findings were seen especially in males.
These findings spurred the interest in smoking as a possible environmental factor influencing RA.
Lindsey A. Criswell MD, MPH & colleagues from University of Iowa conducted an elegant study. They followed 31, 336 women in Iowa who were aged 55 to 69 years in 1986 and who had no history of rheumatoid arthritis. Through 1997, 158 cases of rheumatoid arthritis were identified. They found that cigarette smoking lead to an approximately twofold increased risk of rheumatoid arthritis among postmenopausal women. This study definitely showed that abstinence from smoking may reduce the risk of rheumatoid arthritis among postmenopausal women. They estimated that about 18% of the rheumatoid arthritis in post menopausal women in Iowa was attributable to smoking.
The nurses’ health study followed up 103,818 nurses & found 680 RA cases, diagnosed from 1976 and 2002. The subsequent analysis showed that past and current cigarette smoking were related to the development of RA, in particular seropositive RA.
A recent analysis of 16 studies from 1996 to 2006 also confirmed that smoking is a major risk factor for Rheumatoid arthritis. The risk of developing RA was found to be two times higher for male smokers than for nonsmokers. For women, the risk for smokers is approximately 1.3 times greater than for non-smokers. However, for heavy smokers (20 or more pack-years of smoking), the risk was as high for women as for men.
Scientists from Ireland also confirmed that heavy smokers develop more severe RA & it did adversely affect the RA progression.
Thus it is now clear that smoking is a risk factor for development of RA & also adversely affects the progression of RA. Conversely, quitting smoking may help control one’s RA.
Evidence has now started emerging that smokers may not do as well as non smokers on the treatment front as well. Smokers have been found to have a poor response to TNF alpha blockers as compared to non-smokers.
1. Tuomi T, Heliovaara M, Palosuo T, Aho K. Smoking, lung function, and rheumatoid arthritis. Ann Rheum Dis. 1990;49:753–756.
2. The Effect Of smoking On Clinical, Laboratory, and Radiographic Status in Rheumatoid Arthritis, Frederick Wolfe, M.D., The Journal Of Rheumatology, March 2000.
3. Cigarette smoking and the risk of rheumatoid arthritis among postmenopausal women: Results from the Iowa Women’s Health Study. The American Journal of Medicine Volume 112, Issue 6, 15 April 2002, Pages 465-471
4. Smoking intensity, duration, and cessation, and the risk of rheumatoid arthritis in women. Costenbader KH, Am J Med. 2006 Jun;119(6):503.e1-9
5. Smoking, rheumatoid factor isotypes & severity of Rheumatoid arthritis. Masdottir et al Rheumatology 2000;39:1202-1205
6. Impact of smoking as a risk factor for developing rheumatoid arthritis: a meta-analysis of observational studies D Sugiyama, Ann Rheum Dis 2010;69:70-81
7. Anti-TNF-[alpha] Agents Are Less Effective for the Treatment of Rheumatoid Arthritis in Current Smokers Abhishek, A Journal of Clinical Rheumatology: January 2010 – Volume 16 – Issue 1 – pp 15-18