title: Life-course origins of social inequalities in adult immune cell markers of inflammation in a developing southern Chinese population: the Guangzhou Biobank Cohort Study.
abstract: BACKGROUND
  Socioeconomic position (SEP) throughout life is associated with cardiovascular disease, though the mechanisms linking these two are unclear. It is also unclear whether there are critical periods in the life course when exposure to better socioeconomic conditions confers advantages or whether SEP exposures accumulate across the whole life course. Inflammation may be a mechanism linking socioeconomic position (SEP) with cardiovascular disease. In a large sample of older residents of Guangzhou, in southern China, we examined the association of life course SEP with inflammation.
  
  
  METHODS
  In baseline data on 9,981 adults (≥ 50 years old) from the Guangzhou Biobank Cohort Study (2006-08), we used multivariable linear regression and model fit to assess the associations of life course SEP at four stages (childhood, early adult, late adult and current) with white blood, granulocyte and lymphocyte cell counts.
  
  
  RESULTS
  A model including SEP at all four life stages best explained the association of life course SEP with white blood and granulocyte cell count for men and women, with early adult SEP (education) making the largest contribution. A critical period model best explained the association of life course SEP with lymphocyte count, with sex-specific associations. Early adult SEP was negatively associated with lymphocytes for women.
  
  
  CONCLUSIONS
  Low SEP throughout life may negatively impact late adult immune-inflammatory status. However, some aspects of immune-inflammatory status may be sensitive to earlier exposures, with sex-specific associations. The findings were compatible with the hypothesis that in a developing population, upregulation of the gonadotropic axis with economic development may obscure the normally protective effects of social advantage for men.
authors.affiliation: School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, SAR, China.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: West
authors.forename: Gabriel M
authors.initials: GM
authors.lastname: Leung
authors.forename: Chao Q
authors.initials: CQ
authors.lastname: Jiang
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Elwell-Sutton
authors.forename: Wei S
authors.initials: WS
authors.lastname: Zhang
authors.forename: Tai H
authors.initials: TH
authors.lastname: Lam
authors.forename: Kar K
authors.initials: KK
authors.lastname: Cheng
authors.forename: C Mary
authors.initials: CM
authors.lastname: Schooling
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood*; D002452:Cell Count; D002681:China; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis / Q000276:immunology* / Q000503:physiopathology; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012923:Social Class
chemical_list: D015415:Biomarkers