Passive smoking linked to increased risk of rheumatoid arthritis

Passive smoking during childhood and/or adulthood is associated with increased risk of rheumatoid arthritis (RA), according to a study recently published in RMD Open.

Yann Nguyen, M.D., M.P.H., from the Université Paris-Saclay in Villejuif, France, and colleagues examined the association between exposure to passive smoking and the risk of incident RA in a French prospective cohort of healthy women. Self-reported questionnaires were used to assess exposures to passive smoking.

The researchers identified 698 incident cases of RA among 79,806 women. Overall, 13.5 and 53.6 percent of women were exposed to passive smoking in childhood and adulthood, respectively. In all models, passive smoking in childhood and in adulthood was associated with RA risk (hazard ratios, 1.24 and 1.19, respectively). Never smokers with exposure to passive smoking in childhood and/or adulthood had similar absolute risk of RA as that of ever smokers with no passive smoking exposure (47.6 and 47.2/100,000 person-years, respectively); the highest absolute risk was seen for ever smokers also exposed to passive smoking (53.7/100,000 person-years).

"Passive smoking during childhood and/or adulthood was associated with an increased risk of RA, especially among never-smoking women. Such exposure should be limited as much as possible to prevent the onset of the disease," the authors write. "Even if our study was not designed to investigate this point, this message could especially apply to individuals at risk of RA, for example, relatives of patients with RA."