title: Increased body mass index is associated with earlier time to loss of response to infliximab in patients with inflammatory bowel disease.
abstract: BACKGROUND
  Obesity is an emerging problem in the care of inflammatory bowel disease (IBD) patients and has been associated with a diminished response to adalimumab. Whether obesity influences the response to infliximab (IFX) is not known.
  
  
  METHODS
  A retrospective cohort of 124 subjects with IBD initiating IFX, naive to biologic therapy, was identified. Subjects were stratified according to their weight and body mass index (BMI). The primary outcome was the first occurrence of an IBD flare defined as dose escalation of IFX, corticosteroid use, discontinuation of IFX, hospitalization, or surgery. Multivariable logistic regression was performed considering body mass and BMI as categorical and continuous variables.
  
  
  RESULTS
  Obese (BMI > 30 kg/m) patients with Crohn's disease were more likely to have an IBD flare than nonobese patients (adjusted hazard ratio [HR]: 3.03, P < 0.001); overweight (BMI > 25 kg/m) patients with ulcerative colitis trended toward a similar observation (HR: 9.68, P = 0.06). When considered as continuous variables, increasing mass and BMI were associated with earlier IBD flare in both Crohn's disease (adjusted HR: 1.06 per unit increase in BMI [P = 0.02] and 1.02 per kg increase in body mass [P = 0.02]) and ulcerative colitis (adjusted HR: 1.3 per unit increase in BMI [P = 0.01] and 1.11 per kg increase in body mass [P = 0.004]).
  
  
  CONCLUSIONS
  Increased body weight is associated with an earlier time to loss of response to IFX in Crohn's disease and ulcerative colitis, a novel finding given that IFX is the only antitumor necrosis factor agent whose dosing reflects increased body weight.
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Washington Medical Center, Seattle, WA 98195, USA.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Harper
authors.forename: Mika N
authors.initials: MN
authors.lastname: Sinanan
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Zisman
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015992:Body Mass Index; D003093:Colitis, Ulcerative / Q000150:complications / Q000188:drug therapy*; D003424:Crohn Disease / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000069285:Infliximab; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D011379:Prognosis; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000911:Antibodies, Monoclonal; D000069285:Infliximab