title: The association between psoriasis and obesity: a systematic review and meta-analysis of observational studies.
abstract: OBJECTIVE
  Psoriasis is an inflammatory skin disease affecting 2-4% of the world population. The objective of this study was to perform a systematic review and meta-analysis synthesizing the epidemiological associations between psoriasis and obesity.
  
  
  METHODS
  We searched for observational studies from MEDLINE, EMBASE and Cochrane Central Register from 1 January 1980 to 1 January 2012. We applied the Meta-Analysis of Observational Studies in Epidemiology guidelines in the conduct of this study.
  
  
  METHODS
  We identified 16 observational studies with a total of 2.1 million study participants (201 831 psoriasis patients) fulfilling the inclusion criteria.
  
  
  RESULTS
  Using random-effects meta-analysis, the pooled odds ratio (OR) for obesity among patients with psoriasis was 1.66 (95% confidence interval (CI) 1.46-1.89) compared with those without psoriasis. From the studies that reported psoriasis severity, the pooled OR for obesity among patients with mild psoriasis was 1.46 (95% CI 1.17-1.82) and the pooled OR for patients with severe psoriasis was 2.23 (95% CI 1.63-3.05). One incidence study found that psoriasis patients have a hazard ratio of 1.18 (95% CI 1.14-1.23) for new-onset obesity.
  
  
  CONCLUSIONS
  Overall, compared with the general population, psoriasis patients have higher prevalence and incidence of obesity. Patients with severe psoriasis have greater odds of obesity than those with mild psoriasis.
authors.affiliation: Department of Dermatology, University of California Davis, Sacramento, CA, USA.
authors.forename: A W
authors.initials: AW
authors.lastname: Armstrong
authors.forename: C T
authors.initials: CT
authors.lastname: Harskamp
authors.forename: E J
authors.initials: EJ
authors.lastname: Armstrong