Association of Cigarette Smoking with Risk of Chronic Musculoskeletal Pain: A Meta-Analysis.

BACKGROUND: Chronic musculoskeletal pain (CMP) management is a major global public health goal owing to increased social and economic burdens. However, the risk of CMP in smokers compared with nonsmokers remains uncertain. OBJECTIVES: This study aims to determine the magnitude and importance of the relationship between cigarette smoking and risk of CMP. STUDY DESIGN: A meta-analysis of the CMP risk of cigarette smokers. METHODS: We systematically searched PubMed, Embase, and Cochrane library databases from inception to August 2020. Data extraction and quality assessment were performed by 2 independent reviewers using a standardized extraction checklist. Data were pooled using a random-effects model. RESULTS: In this meta-analysis of 32 studies involving 296,109 participants, current smoking was associated with increased CMP risk (OR: 1.23, 95% CI: 1.09-1.40), whereas ever and past smoking did not show such an association (OR: 1.14, 95% CI: 0.95-1.37; OR: 1.06, 95% CI: 0.83-1.35, respectively). Stratified analyses showed that there was a marked significance in almost all strata of current smokers compared with non-smokers, except for mean age (>= 50 years), location of pain (neck pain, sacral pain, and knee pain), smoking frequency (occasionally), study design (cross-sectional), mean follow-up (< 10 years), and adjustment for confounding factors (>= 6). Interestingly, there was statistically negative association between cigarette smoking and knee pain risk in current smokers, ever smokers, and past smokers. LIMITATIONS: The major limitation of this meta-analysis relates to the heterogeneities across included studies. CONCLUSIONS: Cigarette smoking was associated with increased risk of CMP. In view of the high prevalence of smoking in many countries and the increasing number of CMP patients worldwide, reducing tobacco use should be an important public health strategy to prevent and control the global epidemic of CMP. Future research should attempt to establish whether this association is causal and clarify its mechanisms.