title: Area-level socioeconomic characteristics and incidence of metabolic syndrome: a prospective cohort study.
abstract: BACKGROUND
  The evidence linking socioeconomic environments and metabolic syndrome (MetS) has primarily been based on cross-sectional studies. This study prospectively examined the relationships between area-level socioeconomic position (SEP) and the incidence of MetS.
  
  
  METHODS
  A prospective cohort study design was employed involving 1,877 men and women aged 18+ living in metropolitan Adelaide, Australia, all free of MetS at baseline. Area-level SEP measures, derived from Census data, included proportion of residents completing a university education, and median household weekly income. MetS, defined according to International Diabetes Federation, was ascertained after an average of 3.6 years follow up. Associations between each area-level SEP measure and incident MetS were examined by Poisson regression Generalised Estimating Equations models. Interaction between area- and individual-level SEP variables was also tested.
  
  
  RESULTS
  A total of 156 men (18.7%) and 153 women (13.1%) developed MetS. Each percentage increase in the proportion of residents with a university education corresponded to a 2% lower risk of developing MetS (age and sex-adjusted incidence risk ratio (RR)=0.98; 95% confidence interval (CI) =0.97-0.99). This association persisted after adjustment for individual-level income, education, and health behaviours. There was no significant association between area-level income and incident MetS overall. For the high income participants, however, a one standard deviation increase in median household weekly income was associated with a 29% higher risk of developing MetS (Adjusted RR=1.29; 95%CI=1.04-1.60).
  
  
  CONCLUSIONS
  While area-level education was independently and inversely associated with the risk of developing MetS, the association between area-level income and the MetS incidence was modified by individual-level income.
authors.affiliation: Social Epidemiology and Evaluation Research Group, Sansom Institute for Health Research, and School of Population Health, University of South Australia, Adelaide 5001, Australia. Anh.Ngo@unisa.edu.au.
authors.forename: Anh D
authors.initials: AD
authors.lastname: Ngo
authors.forename: Catherine
authors.initials: C
authors.lastname: Paquet
authors.forename: Natasha J
authors.initials: NJ
authors.lastname: Howard
authors.forename: Neil T
authors.initials: NT
authors.lastname: Coffee
authors.forename: Robert
authors.initials: R
authors.lastname: Adams
authors.forename: Anne
authors.initials: A
authors.lastname: Taylor
authors.forename: Mark
authors.initials: M
authors.lastname: Daniel
mesh_terms: D000328:Adult; D000368:Aged; D001315:Australia / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D015994:Incidence; D007182:Income; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology*; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D012923:Social Class