title: Association of lifecourse socioeconomic status with chronic inflammation and type 2 diabetes risk: the Whitehall II prospective cohort study.
abstract: BACKGROUND
  Socioeconomic adversity in early life has been hypothesized to "program" a vulnerable phenotype with exaggerated inflammatory responses, so increasing the risk of developing type 2 diabetes in adulthood. The aim of this study is to test this hypothesis by assessing the extent to which the association between lifecourse socioeconomic status and type 2 diabetes incidence is explained by chronic inflammation.
  
  
  RESULTS
  We use data from the British Whitehall II study, a prospective occupational cohort of adults established in 1985. The inflammatory markers C-reactive protein and interleukin-6 were measured repeatedly and type 2 diabetes incidence (new cases) was monitored over an 18-year follow-up (from 1991-1993 until 2007-2009). Our analytical sample consisted of 6,387 non-diabetic participants (1,818 women), of whom 731 (207 women) developed type 2 diabetes over the follow-up. Cumulative exposure to low socioeconomic status from childhood to middle age was associated with an increased risk of developing type 2 diabetes in adulthood (hazard ratio [HR] = 1.96, 95% confidence interval: 1.48-2.58 for low cumulative lifecourse socioeconomic score and HR = 1.55, 95% confidence interval: 1.26-1.91 for low-low socioeconomic trajectory). 25% of the excess risk associated with cumulative socioeconomic adversity across the lifecourse and 32% of the excess risk associated with low-low socioeconomic trajectory was attributable to chronically elevated inflammation (95% confidence intervals 16%-58%).
  
  
  CONCLUSIONS
  In the present study, chronic inflammation explained a substantial part of the association between lifecourse socioeconomic disadvantage and type 2 diabetes. Further studies should be performed to confirm these findings in population-based samples, as the Whitehall II cohort is not representative of the general population, and to examine the extent to which social inequalities attributable to chronic inflammation are reversible.
authors.affiliation: Institute of Social and Preventive Medicine (IUMSP), Lausanne University Hospital, Lausanne, Switzerland. silvia.stringhini@chuv.ch
authors.forename: Silvia
authors.initials: S
authors.lastname: Stringhini
authors.forename: G David
authors.initials: GD
authors.lastname: Batty
authors.forename: Pascal
authors.initials: P
authors.lastname: Bovet
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Shipley
authors.forename: Michael G
authors.initials: MG
authors.lastname: Marmot
authors.forename: Meena
authors.initials: M
authors.lastname: Kumari
authors.forename: Adam G
authors.initials: AG
authors.lastname: Tabak
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000150:complications / Q000453:epidemiology*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012923:Social Class; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D002097:C-Reactive Protein