ASSOCIATION BETWEEN PASSIVE SMOKING IN CHILDHOOD AND ADULTHOOD, AND RHEUMATOID ARTHRITIS: RESULTS FROM THE FRENCH E3N-EPIC COHORT STUDY
Authors: Y. Nguyen et al.
We have known for a long time that active smoking, in particular in individuals with underlying genetic predisposition for rheumatoid arthritis (“shared epitope”), is a risk factor for developing rheumatoid arthritis. This study aimed at investigating the impact of passive smoking and the risk of incident RA. In a large prospective cohort of healthy French women (E3N cohort) Passive smoking increased the risk of developing RA by 24%, in particular during childhood. The association of passive smoking during childhood was strongest in never-smoking women (HR 1.42; 95% CI [1.07 to 1.88])!
This study underscores the toxicity of passive exposure to smoking, in particular during childhood, not only for the established cardiovascular or pneumological complications, but also for the increased risk of RA. These findings further support the mucosal origins hypothesis of RA, namely that mucosal inflammation, e.g. produced by smoking, whether actively or passively inhaled, can engender autoimmunity associated with RA. This is a reminder for us as clinicians to ask about passive exposure to tobacco smoke and try to prevent it as much as possible.