Heavy smokers are at increased risk of developing the painful joint disease rheumatoid arthritis, finds a study in the Annals of Rheumatic Diseases. The research also shows that a family history of the disease, a known risk factor for rheumatoid arthritis, was less common among heavy smokers.
The study team analysed the smoking habits of 239 patients with rheumatoid arthritis and 239 healthy people. The patients were also asked if a first or second degree relative had the disease.
The results showed that the patients were significantly more likely to be current smokers than healthy people. Those who had smoked 20 cigarettes a day for between 40 and 50 years were over 13 times as likely to have the disease. Over half the patients with rheumatoid arthritis had no family history of the disease, a known risk factor for developing it. Significantly more of these patients were heavy and current smokers at the time of diagnosis.
Environmental and genetic factors are thought to have a role in the development of rheumatoid arthritis, and cigarette smoking could be one environmental factor, say the authors. Evidence suggests that there is a link between smoking and the production of rheumatoid factor, a marker for the disease. And it would also explain the increased death rates among sufferers, they say.