Association Between Chronic Obstructive Pulmonary Disease And Psoriasis: A Systematic Review And Meta-Analysis

Introduction: It was hypothesized that chronic obstructive pulmonary disease (COPD) might be an autoimmune disease induced by cigarette smoking as emerging evidence has suggested that chronic systemic inflammation plays an important role in the pathogenesis of COPD. Several epidemiological studies have also demonstrated that patients with chronic inflammatory disorders, such as rheumatoid arthritis and systemic lupus erythematosus, have a significantly higher risk of developing COPD. However, the data on psoriasis, another common chronic inflammatory disorder, remain unclear due to conflicting studies. Thus, to further investigate this possible association, we conducted a systematic review and meta-analysis of observational studies that compared the risk of COPD in patients with psoriasis versus participants without it. Methods: Two investigators (P.U. and W.C.) independently searched published studies indexed in MEDLINE, EMBASE and the Cochrane database from inception to May 2014 using the terms for psoriasis and COPD . A manual search of references of selected retrieved articles was also performed. The inclusion criteria were as follows: (1) observational studies published as original studies to evaluate the association between psoriasis and COPD and (2) odds ratios (OR’s), relative risk (RR’s) or hazard ratio (HR’s) or standardized incidence ratio (SIR’s) with 95% confidence intervals (CI’s) were provided. Study eligibility was independently determined by the two investigators noted above. Newcastle-Ottawa scale was used to assess the quality of included studies. RevMan 5.3 software was used for the data analysis. Point estimates and standard errors were extracted from individual studies and were combined by the generic inverse variance method of DerSimonian and Laird. In light of the high likelihood of between study variance, we used a random-effect model rather than a fixed-effect model. The study’s statistical heterogeneity was assessed by Cochran’s Q test. Results: Out of 552 potentially relevant articles, seven studies (five case-control studies and two retrospective cohort studies) were identified and included in the data analysis. The pooled risk ratio of COPD in patients with psoriasis was 1.51 (95% CI, 1.23 to 1.85). The statistical heterogeneity of this meta-analysis was high with an I of 89%. 2 Conclusions: Our study demonstrated a statistically significant increased risk of COPD among patients with psoriasis