title: Impact of obesity in patients infected with 2009 influenza A(H1N1).
abstract: OBJECTIVE
  A large proportion of patients infected with 2009 influenza A(H1N1) (A[H1N1]) are obese. Obesity has been proposed as a risk factor influencing outcome in these patients. However, its role remains unclear. We evaluate the outcome of patients who are obese and infected with A(H1N1) in the ICU, determining whether obesity is a risk factor for mortality.
  
  
  METHODS
  This was a prospective, observational, and multicenter study performed in 144 ICUs in Spain. Data were obtained from the Grupo de Trabajo en Enfermedades Infecciosas de la Sociedad Española de Medicina Intensiva, Crítica y Unidades Coronarias (GTEI/SEMICYUC) registry. Adult patients with A(H1N1) that was confirmed by real-time polymerase chain reaction were included in the analysis. Patients who were obese (BMI > 30) were compared with patients who were nonobese. Cox regression analysis was used to determine adjusted mortality. Differences of P < .05 were considered significant.
  
  
  RESULTS
  In January 2010, the GTEI/SEMICYUC registry had complete records for 416 patients. One hundred and fifty patients (36.1%) were obese, of whom 67 (44.7%) were morbidly obese (BMI > 40). Mechanical ventilation (MV) was more frequently applied in patients who were obese (64% vs 52.4%, P < .01) Patients with obesity remained on MV longer than patients who were nonobese (6.5 ± 10.3 days vs 9.3 ± 9.7 days, P = .02), had longer ICU length of stay (10.8 ± 12.1 days vs 13.7 ± 11.7 days, P = .03), and had longer hospitalization (18.2 ± 14.6 days vs 22.2 ± 16.5 days, P = .02). Mortality adjusted by severity and potential confounders identified that obesity was not significantly associated with ICU mortality (hazard ratio, 1.1; 95% CI, 0.69-1.75; P = .68).
  
  
  CONCLUSIONS
  In our cohort, patients who were obese and infected with A(H1N1) did not have increased mortality. However, there was an association between obesity and higher ICU resource consumption.
authors.affiliation: Critical Care Department, Hospital Universitario Joan XXIII-Centro de Investigación Biomédica en red Enfermedades Respiratorias, Universitat Rovira i Virgili (URV), and Institut d'Investigació Sanitària Pere Virgili (IISPV), Tarragona. Electronic address: emilio.diaz.santos@gmail.com.
authors.forename: Emili
authors.initials: E
authors.lastname: Díaz
authors.affiliation: Critical Care Department, Hospital Universitario Joan XXIII-Centro de Investigación Biomédica en red Enfermedades Respiratorias, Universitat Rovira i Virgili (URV), and Institut d'Investigació Sanitària Pere Virgili (IISPV), Tarragona.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Rodríguez
authors.affiliation: Critical Care Department, Hospital Universitario Joan XXIII-Centro de Investigación Biomédica en red Enfermedades Respiratorias, Universitat Rovira i Virgili (URV), and Institut d'Investigació Sanitària Pere Virgili (IISPV), Tarragona.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Martin-Loeches
authors.affiliation: Critical Care Department, Hospital Universitario de Canarias, Tenerife.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Lorente
authors.affiliation: Critical Care Department, Hospital Reina Sofía, Córdoba.
authors.forename: María
authors.initials: M
authors.lastname: Del Mar Martín
authors.affiliation: Hospital de la Candelaria, Tenerife the Critical Care Department, Hospital Reina Sofía, Córdoba.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Pozo
authors.affiliation: Critical Care Department, Hospital Sistema Andaluz de Salud, Jerez.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Montejo
authors.affiliation: Hospital 12 de Octubre, Madrid the Critical Care Department, Hospital Sistema Andaluz de Salud, Jerez.
authors.forename: Angel
authors.initials: A
authors.lastname: Estella
authors.affiliation: Critical Care Department, Virgen de la Macarena, Sevilla.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Arenzana
authors.affiliation: Critical Care Department, Vall D'Hebron Hospital, Universitat Autònoma de Barcelona, Institut de Recerca Vall D'Hebron Centro de Investigación Biomédica en red de Enfermedades Respiratorias, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Rello
mesh_terms: D018806:APACHE; D000328:Adult; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications* / Q000401:mortality / Q000821:virology; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000401:mortality; D019370:Observation; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012042:Registries; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D018709:Statistics, Nonparametric