title: Association of socioeconomic status with inflammatory markers: a two cohort comparison.
abstract: OBJECTIVE
  To assess the association between socioeconomic status (SES) and inflammatory markers using two different European population samples.
  
  
  METHODS
  We used data from the CoLaus (N=6412, Lausanne, Switzerland) and EPIPorto (N=1205, Porto, Portugal) studies. Education and occupational position were used as indicators of socioeconomic status (SES). High-sensitivity C-reactive protein (hs-CRP) was available for both cohorts. Interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were available in CoLaus; leukocyte count and fibrinogen in EPIPorto.
  
  
  RESULTS
  We showed that low SES was significantly associated with high inflammation in both studies. We also showed that behavioural factors contributed the most to SES differences in inflammation. In both studies the larger difference between the lowest and the highest SES was observed for hs-CRP. In the Swiss sample, a linear association between education and hs-CRP persisted after adjustment for all mediating factors and confounders considered (p for linear trend <0.001).
  
  
  CONCLUSIONS
  Large social differences exist in inflammatory activity, in part independently from demographic and behavioural factors, chronic conditions and medication use. SES differences in inflammation are also similar in countries with different underlying socioeconomic conditions.
authors.affiliation: EPIUnit- Institute of Public Health - University of Porto, Porto, Portugal. Electronic address: silfraga@med.up.pt.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Fraga
authors.affiliation: Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques-Vidal
authors.affiliation: Department of Medicine, Internal Medicine, CHUV and Faculty of Biology and Medicine, Lausanne, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Vollenweider
authors.affiliation: Department of Medicine, Internal Medicine, CHUV and Faculty of Biology and Medicine, Lausanne, Switzerland.
authors.forename: Gérard
authors.initials: G
authors.lastname: Waeber
authors.affiliation: Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland; Unit of Population Epidemiology, Geneva University Hospital, Geneva, Switzerland; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, USA.
authors.forename: Idris
authors.initials: I
authors.lastname: Guessous
authors.affiliation: Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Fred
authors.initials: F
authors.lastname: Paccaud
authors.affiliation: EPIUnit- Institute of Public Health - University of Porto, Porto, Portugal.
authors.forename: Henrique
authors.initials: H
authors.lastname: Barros
authors.affiliation: Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Silvia
authors.initials: S
authors.lastname: Stringhini
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D002908:Chronic Disease; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D015438:Health Behavior; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000453:epidemiology*; D015850:Interleukin-6 / Q000097:blood; D007962:Leukocytes; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D012923:Social Class; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013557:Switzerland / Q000453:epidemiology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D005340:Fibrinogen; D002097:C-Reactive Protein
keywords: Inflammation; Portugal; Socioeconomic status; Switzerland