Background: Ankylosing spondylitis (AS), a rheumatic disease, incapacitates human beings during the most productive stage of their lives, causes functional disturbances, and thus affects both patients and their relatives. Disease activity, functional impairment, and efficacy of treatment are affected by various environmental and genetic factors, one of which is smoking. We investigated smoking's effect on clinical activity and functional impairment in AS.
Patients and methods: Forty-eight patients with back pain and limited movements, diagnosed with AS based on clinical, radiological, and laboratory examinations and referred to the Trakya University School of Medicine Physical Medicine and Rehabilitation Department in Turkey were included in this study. Disease activity was evaluated with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and functional impairment with the Bath Ankylosing Spondylitis Functional Index (BASFI). The Mann-Whitney U test was used to determine relationships between smoking and physical findings, laboratory results, and BASDAI and BASFI scores.
Results: Twenty-four patients were smokers. They had significantly higher BASDAI and BASFI scores and significantly lower forced vital capacity values than nonsmokers (P=0.000, P=0.002, and P=0.001, respectively) (Mann-Whitney U test).
Conclusion: Smoking is associated with poor clinical aspect and functional impairment in AS. The underlying mechanism can be the physical incapacity caused by smoking.