title: Smoking is associated with an increased risk of developing ACPA-positive but not ACPA-negative rheumatoid arthritis in Asian populations: evidence from the Malaysian MyEIRA case-control study.
abstract: We investigated the association between cigarette smoking and the risk of developing rheumatoid arthritis (RA) in the Malaysian population. A total of 1,056 RA patients and 1,416 matched controls aged 18-70 years within a defined area of Peninsular Malaysia were evaluated in a case-control study between August 2005 and December 2009. A case was defined as a person with early diagnosed RA using the 1987 American College of Rheumatology criteria for RA. Controls were randomly selected matched for sex, age, and residential area. Cases and controls answered a questionnaire on a broad range of issues, including lifestyle factors and smoking habits wherein current and former smoking was classified as ever-smoking. The presence of anti-citrullinated peptide antibodies (ACPA) was determined for cases and controls. We found that ever-smokers had an increased risk of developing ACPA-positive RA [odds ratio (OR) = 4.1, 95% confidence interval (CI) 1.9-9.2] but not ACPA-negative RA (OR = 0.7, 95% CI 0.3-2.0), compared with never-smokers. A significant dose-response relationship between cumulative dose of smoking and risk of ACPA-positive RA was observed (<20 pack-years OR = 3.3, 95% CI 1.1-9.8; at least 20 pack-years OR = 5.2, 95% CI 1.6-17.6). Hence, smoking is associated with an increased risk of ACPA-positive RA in the Malaysian population, in which the genetic context is similar to several other Asian countries.
authors: Institute of Environmental Medicine, Karolinska Institutet, Nobel väg 13, Box 210, 171 77, Stockholm, Sweden. abqariyah.yahya@gmail.com
authors: Abqariyah
authors: A
authors: Yahya
authors: Camilla
authors: C
authors: Bengtsson
authors: Too Chun
authors: TC
authors: Lai
authors: Per T
authors: PT
authors: Larsson
authors: Amal Nasir
authors: AN
authors: Mustafa
authors: Nor Aini
authors: NA
authors: Abdullah
authors: Norasiah
authors: N
authors: Muhamad
authors: Heselynn
authors: H
authors: Hussein
authors: Lars
authors: L
authors: Klareskog
authors: Lars
authors: L
authors: Alfredsson
authors: Shahnaz
authors: S
authors: Murad
mesh_terms: D001172:Arthritis, Rheumatoid / Q000208:ethnology / Q000209:etiology* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D002681:China / Q000208:ethnology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D018570:Risk Assessment; D012907:Smoking / Q000009:adverse effects*; D011795:Surveys and Questionnaires; D061665:Time-to-Treatment
chemical_list: D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide