title: Is leg length a biomarker of childhood conditions in older Chinese women? The Guangzhou Biobank Cohort Study.
abstract: OBJECTIVE
  In developed western populations longer legs have been shown to be a biomarker of better early childhood conditions. It was hypothesised that in transitioning populations better childhood conditions may bring forward puberty and thus decrease leg length, counteracting the overall positive effect of a favourable childhood environment on leg growth.
  
  
  METHODS
  Structural equation modelling was used to assess the interrelationship of age, education, father's job, age of menarche and leg length in a cross-sectional sample of 7273 Chinese women aged at least 50 years from the Guangzhou Biobank Cohort Study.
  
  
  RESULTS
  Leg length had no significant association with education or father's occupation on bivariable testing. After including age of menarche in the model, education was associated with longer legs (0.45 cm longer per 10 years of education, 95% CI 0.20 to 0.71). Education was also associated with younger age of menarche (1.21 years younger per 10 years of education, 95% CI 1.09 to 1.34), which was in turn associated with shorter legs (0.23 cm shorter per year of menarche earlier, 95% CI 0.18 to 0.27).
  
  
  CONCLUSIONS
  In older Chinese women leg length is not a universal biomarker of childhood conditions, when proxied by her educational level and father's occupation. Nutritionally driven epigenetic influences operating over generations may constrain growth in very recently developed populations. Given the impact of childhood conditions on health, and the dearth of long-term records outside the industrialised world, a greater understanding of the influences on growth in the developing world is required.
authors.affiliation: Department of Community Medicine, School of Public Health, The University of Hong Kong, Hong Kong SAR, China.
authors.forename: C M
authors.initials: CM
authors.lastname: Schooling
authors.forename: C Q
authors.initials: CQ
authors.lastname: Jiang
authors.forename: M
authors.initials: M
authors.lastname: Heys
authors.forename: W S
authors.initials: WS
authors.lastname: Zhang
authors.forename: X Q
authors.initials: XQ
authors.lastname: Lao
authors.forename: P
authors.initials: P
authors.lastname: Adab
authors.forename: B J
authors.initials: BJ
authors.lastname: Cowling
authors.forename: G N
authors.initials: GN
authors.lastname: Thomas
authors.forename: K K
authors.initials: KK
authors.lastname: Cheng
authors.forename: T H
authors.initials: TH
authors.lastname: Lam
authors.forename: G M
authors.initials: GM
authors.lastname: Leung
mesh_terms: D000367:Age Factors; D000368:Aged; D000886:Anthropometry / Q000379:methods; D044466:Asian People / Q000706:statistics & numerical data*; D001827:Body Height; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D007866:Leg / Q000033:anatomy & histology*; D008572:Menarche / Q000208:ethnology; D008875:Middle Aged; D008954:Models, Biological; D012923:Social Class; D012924:Social Conditions / Q000706:statistics & numerical data*