Abstract
Context: There is now consistent evidence from population and epidemiological studies that cigarette smoking is an independent risk factor for Rheumatoid Arthritis (RA), via Rheumatoid Factor (RF) production (Deighton, 1997; Saag, 1997; Silman, 1996; Uhlig, 1999; Wolfe, 2000). Antinuclear Antibodies (ANA) are another collection of autoantibodies that are being associated with smoking and RA initiation. To our knowledge, no studies have examined the effects of smoking on both ANA and RF simultaneously in healthy subjects.
Objectives: To determine whether cigarette smoking has an effect on ANA and RF positivity in healthy blood donors.
Design, Setting, Participants: This was a cross-sectional, observational, retrospective study. 576 consenting volunteer blood donors recruited from the local blood banks gave additional blood samples, answered the general blood bank questionnaire and our study questionnaire. Data on demographics, smoking history and selected RA risk factors were collected.
Main Outcome Measures: ANA and RF positivity.
Results:Moderate and light lifetime smoking was protective for ANA positivity relative to non-smoking and heavy smoking (O/?=2.670, 95% C7= 1.322-5.391, /?=0.006). Simple contrasts suggested this was due to moderate lifetime smoking being protective for ANA positivity compared to non-smoking (<9/?=0.337, 95% C7=0.115-0.989, p=0.048) and heavy smoking (<9/?=0.173, 95% C/=0.055-0.545,/?=0.003). No associations were found between current smoking status and ANA or RF positivity. Nor was one found with past and current second hand smoke. For never smokers there was an interaction of second hand smoke exposure with age. Those not exposed to second hand smoke showed increasing probability of ANA positivity with age. Those exposed to second hand smoke showed no such increase (0/?=0.908, 95% C7=0.828-0.996, /?=0.042). Total years smoked for exsmokers increased the likelihood of testing positive for ANA (0/?=l.O45, 95% C/+1.007- 1.084, /?=0.021). No associations were found between smoking status and ANA or RF positivity.
Conclusion: Immunological changes induced by smoking or nicotine may help explain the observed biphasic effect found with ANA positivity. For ex-smokers, smoke exposure may produce a permanent physiological change on the formation of ANA complexes that is irreversible.
School
School of Public Health
First Advisor
Jerry W. Lee
Second Advisor
Kristian Lindsted
Third Advisor
Edwin Krick
Degree Name
Doctor of Public Health (DrPH)
Degree Level
Ph.D.
Year Degree Awarded
2003
Date (Title Page)
6-2003
Language
English
Library of Congress/MESH Subject Headings
Arthritis, Rheumatoid -- etiology; Smoking -- adverse effects; Antibodies, Antinuclear.
Type
Dissertation
Page Count
xiii; 117
Digital Format
Digital Publisher
Loma Linda University Libraries
Copyright
Author
Usage Rights
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Recommended Citation
Nyanzi, Susan, "Are Antinuclear Antibodies and Rheumatiod Factor Positivity More Prevalent in Apparently Healthy Smokers Compared to Ex-Smokers and Never Smokers?" (2003). Loma Linda University Electronic Theses, Dissertations & Projects. 931.
https://scholarsrepository.llu.edu/etd/931
Collection
Loma Linda University Electronic Theses and Dissertations
Collection Website
http://scholarsrepository.llu.edu/etd/
Repository
Loma Linda University. Del E. Webb Memorial Library. University Archives