RT Journal Article SR Electronic T1 Passive smoking in childhood and adulthood and risk of rheumatoid arthritis in women: results from the French E3N cohort study JF RMD Open JO RMD Open FD EULAR SP e001980 DO 10.1136/rmdopen-2021-001980 VO 8 IS 1 A1 Yann Nguyen A1 Carine Salliot A1 Amandine Gelot A1 Xavier Mariette A1 Marie-Christine Boutron-Ruault A1 Raphaele Seror YR 2022 UL http://rmdopen.bmj.com/content/8/1/e001980.abstract AB Objective The association between passive smoking exposure in childhood or in adulthood, and the risk of rheumatoid arthritis (RA) has been incompletely investigated. We aimed to assess the relationship between exposure to passive smoking and the risk of incident RA in a French prospective cohort of healthy women.Methods The E3N Study (Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale) is a French prospective cohort of women included in 1990. Exposures to passive smoking were assessed using self-reported questionnaires. RA cases were self-reported and subsequently validated. Cox proportional hazards regression models adjusted for age and for potential confounders were used to estimate HRs and 95% CIs for incident RA.Results Among 79 806 women, 698 incident cases of RA were identified; 10 810 (13.5%) women were exposed to passive smoking in childhood, and 42 807 (53.6%) in adulthood. Median age at inclusion was 47.8 years. Passive smoking in childhood and in adulthood was associated with RA risk in all models (HRs (95% CIs) 1.24 (1.01 to 1.51) and 1.19 (1.02 to 1.40), respectively). The absolute risk of RA among never smokers with exposure to passive smoking in childhood and/or adulthood (47.6/100 000 person-years) was close to the risk of ever smokers with no passive smoking exposure (47.2/100 000 person-years), while it was highest in ever smokers also exposed to passive smoking (53.7/100 000 person-years).Conclusion Exposure to passive smoking in childhood and/or adulthood increases the risk of RA by the same order than active smoking. Such exposure should be suppressed, especially in individuals at risk of RA.Data are available upon reasonable request.