Smoking associated with reduced odds of Sjögren’s syndrome among rheumatoid arthritis patients

Abstract

Objective

The objective of this medical record review study is to define the association between smoking and Sjӧgren’s syndrome (SS) in a large rheumatoid arthritis (RA) cohort.

Methods

Electronic health records from a population-based cohort were screened for RA eligibility between 2005 and 2018. Inclusion criteria were age ≥ 18 years, two or more RA diagnoses, including two diagnoses by a rheumatologist, or positive rheumatoid factor or anti-cyclic citrullinated peptide (anti-CCP) antibody. The independent variable, smoking status, was defined as never, current, or past. The outcome, SS, was defined by two or more ICD-9 codes. Multivariable logistic regression was performed to determine odds ratios (ORs) of SS adjusted for age, sex, and race.

Results

Among 1861 patients with RA identified for cohort inclusion, 1296 had a reported smoking status. Current smokers were younger and less likely to be female than never smokers. The adjusted OR of current compared to never smokers was negatively associated with SS [OR 0.20, 95% confidence interval (CI) 0.06–0.65]. Female sex and age were associated with SS (OR 2.70, 95% CI 1.18–6.14; OR 3.75, 95% CI 1.23–11.4).

Conclusion

We report that RA patients who currently smoke had 80% lower odds of SS. Age had a 3.7-fold association and female sex a 2.7-fold association with SS among RA patients. Our data suggest a negative correlation between current smoking and prevalent SS among RA patients. Prospective studies examining pack-year relationships or smoking cessation could further examine risk reduction and causality to follow-up our cross-sectional observational study.

Acknowledgements

The project described was supported by the Clinical and Translational Science Award (CTSA) program, through the NIH National Center for Advancing Translational Sciences (NCATS) [grant nos UL1TR002373 and KL2TR002374]. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This work was supported by the National Center for Advancing Translational Sciences [Clinical and Translational Science Award Program U].

Disclosure statement

The authors of this paper have no current financial support or other benefits from commercial sources for the reported work, or any other financial interests that could create a potential conflict of interest or appearance of a conflict of interest with regard to the work.

Ethics and consent

The procedures followed in this study included waiver of informed consent after approval by the Minimal Risk Institutional Review Board and aligned with the Declaration of Helsinki.

References