title: Obesity is associated with a lower probability of achieving sustained minimal disease activity state among patients with psoriatic arthritis.
abstract: OBJECTIVE
  To assess whether overweight and obese patients with psoriatic arthritis (PsA) are less likely to achieve sustained minimal disease activity (MDA) state compared to patients with normal weight.
  
  
  METHODS
  A cohort of patients was assessed at the University of Toronto PsA clinic at 6-12-month intervals according to a standard protocol from 2003 to 2012. Patients were categorised into the following groups according to their body mass index (BMI): normal (<25), overweight (25-30), and obese (>30). Sustained MDA was defined as achieving low disease activity state in five or more of the following domains for at least 1 year: skin, enthesitis, tender and swollen joint counts, pain, patient global assessment and function. Proportional odds discrete time to event analysis was used to investigate the association between BMI category and the achievement of sustained MDA.
  
  
  RESULTS
  Of the 557 patients included in the study, 36.2% were classified as overweight and 35.4% were obese. Overall, 66.1% of the patients achieved sustained MDA during the follow-up period. A dose-response association was found between obesity and the probability of achieving sustained MDA in the multivariate regression analysis. Patients in the higher BMI categories were less likely to achieve sustained MDA compared those in the lowest BMI category (overweight: OR 0.66 p=0.003; obese: OR 0.53 p<0.0001) after adjusting for potential confounding variables.
  
  
  CONCLUSIONS
  Overweight and obese patients with PsA are less likely to achieve sustained MDA compared to those of normal weight.
authors.affiliation: University of Toronto Psoriatic Arthritis Clinic, Centre for Prognosis Studies in the Rheumatic Diseases-Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Lihi
authors.initials: L
authors.lastname: Eder
authors.affiliation: University of Toronto Psoriatic Arthritis Clinic, Centre for Prognosis Studies in the Rheumatic Diseases-Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Arane
authors.initials: A
authors.lastname: Thavaneswaran
authors.affiliation: University of Toronto Psoriatic Arthritis Clinic, Centre for Prognosis Studies in the Rheumatic Diseases-Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Vinod
authors.initials: V
authors.lastname: Chandran
authors.affiliation: Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cook
authors.affiliation: University of Toronto Psoriatic Arthritis Clinic, Centre for Prognosis Studies in the Rheumatic Diseases-Toronto Western Hospital, Toronto, Ontario, Canada.
authors.forename: Dafna D
authors.initials: DD
authors.lastname: Gladman
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D015535:Arthritis, Psoriatic / Q000188:drug therapy* / Q000453:epidemiology; D015992:Body Mass Index; D015331:Cohort Studies; D015897:Comorbidity; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology; D011336:Probability; D011446:Prospective Studies; D012044:Regression Analysis; D012074:Remission Induction; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents
keywords: Disease Activity; Psoriatic Arthritis; Spondyloarthritis