Vol.22 No.4

Original Article

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

Authors

Abqariyah Yahya1,2 , Camilla Bengtsson1 , Too Chun Lai2,3 , Per T. Larsson4 , Amal Nasir Mustafa2 , Nor Aini Abdullah2 , Norasiah Muhamad2 , Heselynn Hussein5 , Lars Klareskog3 , Lars Alfredsson1 , Shahnaz Murad2

  • Institute of Environmental Medicine, Karolinska Institutet, Nobel väg 13, Box 210, 171 77, Stockholm, Sweden
  • Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
  • Rheumatology Unit, Department of Medicine, Karolinska University Hospital Solna, Building D2:02, 171 76, Stockholm, Sweden
  • Rheumatology Unit, Department of Medicine, Karolinska Hospital Huddinge, R92, 14186, Stockholm, Sweden
  • Department of Medicine, Putrajaya Hospital, Precinct 7, 62250, Putrajaya, Malaysia
Received:

28 June 2011

Accepted:

26 September 2011

Published online:

18 October 2011

Full Text

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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 eversmoking. 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 neversmokers. 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 ACPApositive RA in the Malaysian population, in which the genetic context is similar to several other Asian countries.

Key words

Anti-citrullinated peptide antibody (ACPA) - Cigarette smoking - Malaysia - Rheumatoid arthritis - Risk factor