We studied the prevalence and effect on disease activity of ever having had second-hand exposure to tobacco smoke in Swedish rheumatoid arthritis (RA) patients who had never smoked.
Between 1992 and 2005, 2,800 patients were included in the BARFOT early-RA study in Sweden. Disease Activity Score 28 joints (DAS28), C-reactive protein (CRP), Health Assessment Questionnaire (HAQ), rheumatoid factor (RF), general health and pain visual analogue scales (VAS), and drug treatment were registered at inclusion and at follow-up at 3, 6, and 12 months and 2 and 5 years. EULAR response criteria were applied at the same follow-up points. In 2010, a self-completion postal questionnaire was sent to 2,102 patients in the BARFOT study enquiring about lifestyle habits such as whether they had ever been exposed to tobacco smoke as a result of someone else smoking.
A total of 963/1,421 patients (68%) had had second-hand exposure to tobacco smoke. At 3, 6, and 12 months, at 2 years, and at 5 years of follow-up, there were no differences in EULAR response between patients who had never smoked and who had been exposed or had not been exposed second-hand to tobacco smoke (p=0.91, p=0.88, p=0.84, p=0.61 and p=0.85, respectively).
We did not find any association between second-hand exposure to tobacco smoke and disease activity in RA.