title: The influence of obesity on response to tumour necrosis factor-α inhibitors in psoriatic arthritis: results from the DANBIO and ICEBIO registries.
abstract: OBJECTIVE
  To investigate the impact of obesity on response to the first TNF-α inhibitor (TNFI) treatment course in patients with PsA followed in routine care.
  
  
  METHODS
  We performed an observational cohort study based on the Danish and Icelandic biologics registries. Kaplan-Meier plots, Cox and logistic regression analyses were performed to study the impact of obesity (BMI ⩾30 kg/m2) on TNFI adherence and response after 6 months (according to 20/50/70% improvement in ACR criteria and EULAR criteria). Subanalyses studied the impact of obesity according to gender, TNFI type and nationality.
  
  
  RESULTS
  Among 1943 PsA patients (193 Icelandic/1750 Danish) identified in the registries, 1271 (65%) had available BMI and 408 (32%) were obese. The median follow-up-time was 1.5 years [interquartile range (IQR) 0.5-3.9]. Obese patients had higher baseline disease activity, for example, 28-joint DAS [mean 4.6 (sd 1.2) vs 4.4 (1.2)]; CRP [median 9 mg/l (IQR 5-19) vs 7 (3-18)] and visual analogue scale-pain [66 mm (IQR 48-76) vs 60 (38-74)], compared with non-obese patients (all P < 0.05). TNFI adherence was shorter in obese patients, especially among men, where the median TNFI duration was 2.5 years (95% CI 1.7, 3.2) in obese vs 5.9 (4.1, 7.7) in non-obese patients (P < 0.01). A EULAR good or moderate (EGOM) response was achieved by 55% of obese vs 65% of non-obese patients after 6 months (P = 0.02). In multivariable analyses, obesity increased the risk of TNFI withdrawal [hazard ratio 1.6 (95% CI 1.3, 2.0)] and reduced odds for EGOM response [odds ratio 0.47 (95% CI 0.29, 0.72)]. The impact of obesity was significant across genders, TNFI types and nationality.
  
  
  CONCLUSIONS
  Obesity was associated with higher disease activity and seemed to diminish response and adherence to TNFIs in PsA.
authors.affiliation: Department of Rheumatology, Gentofte Hospital, Rigshospitalet, Hellerup pilhoejgaard@gmail.com pil.hoejgaard.01@regionh.dk.|Bispebjerg and Frederiksberg Hospital, Parker Institute, Frederiksberg.
authors.forename: Pil
authors.initials: P
authors.lastname: Højgaard
authors.affiliation: Department of Rheumatology, Gentofte Hospital, Rigshospitalet, Hellerup.|DANBIO Registry, Gentofte Hospital, Rigshospitalet, Hellerup.
authors.forename: Bente
authors.initials: B
authors.lastname: Glintborg
authors.affiliation: Bispebjerg and Frederiksberg Hospital, Parker Institute, Frederiksberg.
authors.forename: Lars Erik
authors.initials: LE
authors.lastname: Kristensen
authors.affiliation: Landspitali University Hospital, Center for Rheumatology Research (ICEBIO).|Faculty of Medicine, University of Iceland.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Gudbjornsson
authors.affiliation: Faculty of Medicine, University of Iceland.|Department for Scientific Affairs, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Thorvardur Jon
authors.initials: TJ
authors.lastname: Love
authors.affiliation: Department of Rheumatology, Gentofte Hospital, Rigshospitalet, Hellerup.|Bispebjerg and Frederiksberg Hospital, Parker Institute, Frederiksberg.|Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Dreyer
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D015535:Arthritis, Psoriatic / Q000188:drug therapy*; D001688:Biological Products / Q000627:therapeutic use*; D000068582:Certolizumab Pegol / Q000627:therapeutic use; D003718:Denmark; D000068800:Etanercept / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007055:Iceland; D000069285:Infliximab / Q000627:therapeutic use; D053208:Kaplan-Meier Estimate; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D011446:Prospective Studies; D012042:Registries; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D001688:Biological Products; D014409:Tumor Necrosis Factor-alpha; C529000:golimumab; D000069285:Infliximab; D000068879:Adalimumab; D000068800:Etanercept; D000068582:Certolizumab Pegol
keywords: anti-TNF drugs; obesity; outcome measures; psoriatic arthritis; registry