title: Obesity in early adulthood as a risk factor for psoriatic arthritis.
abstract: OBJECTIVE
  To study whether obesity increases the risk of psoriatic arthritis (PsA), given that obesity is a risk factor for psoriasis and is associated with more severe disease.
  
  
  METHODS
  Case series. We used Cox regression analysis to study the relationship between obesity and PsA while controlling for age at psoriasis onset, current body mass index (BMI), sex, family history of psoriasis, worst-ever body surface area (BSA) involvement, Koebner phenomenon, and nail involvement.
  
  
  METHODS
  Dermatology clinics at the University of Utah School of Medicine. Patients Volunteer sample of patients with dermatologist-diagnosed psoriasis enrolled in the Utah Psoriasis Initiative from November 2002 to October 2008 (943 subjects; 50.2% women, 49.8% men).
  
  
  METHODS
  Physician diagnosis of PsA from self-report questionnaire.
  
  
  RESULTS
  In our subjects, we found that BMI at age 18 years was predictive of PsA (odds ratio [OR], 1.06) (P < .01) over and above control variables. Other variables that were predictors of PsA included younger age at psoriasis onset (odds ratio [OR], 0.98) (P < .01), female sex (OR, 1.45) (P = .01), higher worst-ever BSA involvement with psoriasis (OR, 1.01) (P = .04), Koebner phenomenon (OR, 1.59) (P < .01), and nail involvement (OR, 1.76) (P < .01). Current BMI and family history of psoriasis were not significant predictors of PsA.
  
  
  CONCLUSIONS
  This study suggests that obesity at age 18 years increases the risk of developing PsA. Adiposity is associated with higher levels of inflammatory cytokines known to be associated with psoriasis. This inflammatory milieu could increase the risk of PsA in predisposed subjects. Prevention and early treatment of obesity may decrease the risk of PsA.
authors.affiliation: Department of Dermatology, University of Utah School of Medicine, 30 North 1900 East, Salt Lake City, UT 84132, USA. razi.soltani@hsc.utah.edu
authors.forename: Razieh
authors.initials: R
authors.lastname: Soltani-Arabshahi
authors.forename: Bob
authors.initials: B
authors.lastname: Wong
authors.forename: Bing-Jian
authors.initials: BJ
authors.lastname: Feng
authors.forename: David E
authors.initials: DE
authors.lastname: Goldgar
authors.forename: Kristina Callis
authors.initials: KC
authors.lastname: Duffin
authors.forename: Gerald G
authors.initials: GG
authors.lastname: Krueger
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D015535:Arthritis, Psoriatic / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D015992:Body Mass Index; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000453:epidemiology; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014589:Utah / Q000453:epidemiology; D055815:Young Adult