To investigate the association between snuff use (smokeless tobacco containing nicotine) and the risk of anti–citrullinated protein/peptide antibody (ACPA)–positive and ACPA-negative rheumatoid arthritis (RA).
Data from the Swedish Epidemiological Investigation of Rheumatoid Arthritis, a population-based case–control study including 1,998 incident cases and 2,252 randomly selected controls (matched on age, sex, and residential area) ages 18–70 years, were analyzed. Ever, current, and past moist snuff users were compared with never users. We calculated odds ratios (ORs) with 95% confidence intervals (95% CIs) by means of unconditional logistic regression models. All analyses were adjusted for cigarette smoking, alcohol consumption, and the matching variables.
In total, 254 (13%) cases were ever moist snuff users compared with 290 (13%) controls, resulting in an OR of 1.0 (95% CI 0.8–1.2) of RA overall. When exposure to moist snuff was analyzed in relation to ACPA-positive and ACPA-negative disease, no associations were observed. Neither current nor past moist snuff use was related to the risk of any of the 2 RA subgroups. Analyses restricted to never smokers provided similar results.
The use of moist snuff was not associated with the risk of either ACPA-positive or ACPA-negative RA. The increased risk of RA associated with smoking is most probably not due to nicotine.