Associations of cigarette smoking with rheumatoid arthritis in African Americans.

Academic Article

Abstract

  • OBJECTIVE: To examine the associations of cigarette smoking with rheumatoid arthritis (RA) in African Americans, and to determine whether this association is impacted by the HLA-DRB1 shared epitope (SE). METHODS: Smoking status, cumulative smoking exposure, and SE status were determined in African American patients with RA and African American healthy controls. Associations of smoking with RA were examined using age- and sex-adjusted logistic regression analyses. Additive and multiplicative SE-smoking interactions were examined. RESULTS: After adjustment for age and sex, ever smoking (odds ratio [OR] 1.45, 95% confidence interval [95% CI] 1.07, 1.97) and current smoking (OR 1.56, 95% CI 1.07, 2.26), relative to never smoking, were more common in African American patients with RA (n = 605) than in controls (n = 255). The association of smoking with RA was limited to those with a cumulative exposure exceeding 10 pack-years, associations that were evident both in autoantibody-positive and in autoantibody-negative disease. There was evidence of a significant additive interaction between SE status and heavy smoking (≥10 pack-years) in relation to RA risk (attributable proportion [AP] due to interaction 0.58, P = 0.007), with similar results for the additive interaction between SE status and ever smoking (AP 0.47, P = 0.006). There was no evidence of multiplicative interactions. CONCLUSION: Among African Americans, cigarette smoking is associated not only with the risk of autoantibody-positive RA but also with the risk of autoantibody-negative disease. The risk of RA attributable to smoking is limited to African Americans with more than 10 pack-years of exposure and is more pronounced among individuals positive for the HLA-DRB1 SE.
  • Published In

    Keywords

  • Adult, African Americans, Aged, Alleles, Arthritis, Rheumatoid, Autoantibodies, Case-Control Studies, Epitopes, Female, HLA-DR Antigens, HLA-DRB1 Chains, Humans, Logistic Models, Male, Middle Aged, Risk Factors, Smoking, Time Factors
  • Digital Object Identifier (doi)

    Pubmed Id

  • 11531933
  • Author List

  • Mikuls TR; Sayles H; Yu F; Levan T; Gould KA; Thiele GM; Conn DL; Jonas BL; Callahan LF; Smith E
  • Start Page

  • 3560
  • End Page

  • 3568
  • Volume

  • 62
  • Issue

  • 12