title: Obesity and risk of infection: results from the Danish Blood Donor Study.
abstract: BACKGROUND
  It is well known that obesity complicates the course of several diseases. However, it is unknown whether obesity affects the risk of infection among healthy individuals.
  
  
  METHODS
  We included 37,808 healthy participants from the Danish Blood Donor Study, who completed a questionnaire on health-related items. Obesity was defined as a body mass index ≥ 30 kg/m(2). Infections among participants were identified by relevant ICD-10 codes in the Danish National Patient Register and Anatomical Therapeutic Chemical (ATC) codes in the Danish Prescription Register. Multivariable Cox proportional hazards analysis with age as the underlying timescale was used as the statistical model.
  
  
  RESULTS
  During 113,717 person-years of observation, 1,233 participants were treated for infection at a hospital. Similarly, during 58,411 person-years of observation, 15,856 participants filled at least one prescription of antimicrobials. Obesity was associated with risk of hospital-based treatment for infection (women: hazard ratio [HR] = 1.5, 95% confidence interval [CI] = 1.1, 1.9; men: HR = 1.5, 95% CI = 1.2, 1.9). For specific infections, obesity was associated with increased risk of abscesses (both sexes), infections of the skin and subcutaneous tissue (men), and respiratory tract infections and cystitis (women). Similarly, obesity was associated with filled prescriptions of antimicrobials overall (women: HR = 1.22, 95% CI = 1.14, 1.30; men: HR = 1.23, 95% CI: 1.15, 1.33) and particularly with phenoxymethylpenicillin, macrolides, dicloxacillin and flucloxacillin, and broad-spectrum penicillins.
  
  
  CONCLUSIONS
  In a large cohort of healthy individuals, obesity was associated with risk of infection. This result warrants further studies of metabolism and the immune response.
authors.affiliation: From the aDepartment of Clinical Immunology, Aarhus University Hospital, Aarhus N, Denmark; bDepartment of Clinical Immunology, Naestved Hospital, Naestved, Denmark; cDepartment of Epidemiology Research, Statens Serum Institut, Copenhagen S, Denmark; dDepartment of Clinical Microbiology, Aarhus University Hospital, Aarhus N, Denmark; and eDepartment of Clinical Immunology, Copenhagen University Hospital, Rigshospitalet, Copenhagen S, Denmark.
authors.forename: Kathrine Agergård
authors.initials: KA
authors.lastname: Kaspersen
authors.forename: Ole Birger
authors.initials: OB
authors.lastname: Pedersen
authors.forename: Mikkel Steen
authors.initials: MS
authors.lastname: Petersen
authors.forename: Henrik
authors.initials: H
authors.lastname: Hjalgrim
authors.forename: Klaus
authors.initials: K
authors.lastname: Rostgaard
authors.forename: Bjarne Kuno
authors.initials: BK
authors.lastname: Møller
authors.forename: Cecilie
authors.initials: C
authors.lastname: Juul-Sørensen
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kotzé
authors.forename: Khoa Manh
authors.initials: KM
authors.lastname: Dinh
authors.forename: Lise Tornvig
authors.initials: LT
authors.lastname: Erikstrup
authors.forename: Erik
authors.initials: E
authors.lastname: Sørensen
authors.forename: Lise Wegner
authors.initials: LW
authors.lastname: Thørner
authors.forename: Kristoffer Sølvsten
authors.initials: KS
authors.lastname: Burgdorf
authors.forename: Henrik
authors.initials: H
authors.lastname: Ullum
authors.forename: Christian
authors.initials: C
authors.lastname: Erikstrup
mesh_terms: D000038:Abscess / Q000188:drug therapy / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use; D001782:Blood Donors; D015992:Body Mass Index; D015331:Cohort Studies; D003556:Cystitis / Q000188:drug therapy / Q000453:epidemiology*; D003718:Denmark / Q000453:epidemiology; D004009:Dicloxacillin / Q000627:therapeutic use; D005260:Female; D005436:Floxacillin / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D007239:Infections / Q000188:drug therapy / Q000453:epidemiology; D018942:Macrolides / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology*; D010404:Penicillin V / Q000627:therapeutic use; D010406:Penicillins / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000453:epidemiology*; D012307:Risk Factors; D012737:Sex Factors; D018461:Soft Tissue Infections / Q000188:drug therapy / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D018942:Macrolides; D010406:Penicillins; D005436:Floxacillin; D004009:Dicloxacillin; D010404:Penicillin V