Light smoking linked to increased risk of rheumatoid arthritis
Published on 22 April 2013
Women who smoke a few cigarettes each day may increase their chances of developing rheumatoid arthritis and this heightened risk remains for many years after quitting, a study has found.
Researchers analysed data from the Swedish Mammography Cohort, a group of 34,101 women between the ages of 54 and 89 years who were followed from January 2003 until December 2010.
A total of 219 cases of rheumatoid arthritis were identified and the researchers identified clear links between smoking and arthritis risk.
Women who smoked between one and seven cigarettes per day were more than twice as likely to be diagnosed with rheumatoid arthritis as those who had never smoked.
The longer a woman had smoked for, the greater her risk of rheumatoid arthritis.
While giving up smoking did help to reduce the risk of the disease, women who had previously smoked still had a greater risk than those who had never smoked for many years after quitting.
Even after 15 years of abstinence, the risk of rheumatoid arthritis had still only declined by about 30 per cent among former smokers.
The findings are published in the journal Arthritis Research & Therapy and indicate that women can reduce their risk of rheumatoid arthritis by not taking up smoking.
Lead researcher Dr Daniela Di Giuseppe, from the Karolinska Institute and Karolinska University Hospital, concluded: "The clearly increased risk of developing rheumatoid arthritis, even many years after giving up, is another reason to stop smoking as soon as possible and highlights the importance of persuading women not to start at all."
Professor Alan Silman, medical director of Arthritis Research UK, said: "In rheumatoid arthritis the immune system attacks the lining of the joints, which causes inflammation leading to pain and swelling. We do not know all of the causes of this inflammation but we've known for some time that rheumatoid arthritis is more common in people who smoke.
"This is particularly true for men and the level of risk varies depending on the genes we inherit from our parents. This study further develops our understanding of the link between smoking and rheumatoid arthritis, suggesting that even light smokers could be increasing their risk of getting the disease."