title: Socio-demographic predictors of age at menarche in a group of Colombian university women.
abstract: BACKGROUND
  Age at menarche is an important developmental milestone known to be modified by social and environmental factors. The determinants and potential change over time of age at menarche in Colombia are not well documented.
  
  
  OBJECTIVE
  To obtain a current estimate of age at menarche in Colombia and to examine the associations between socio-demographic characteristics and age at menarche.
  
  
  METHODS
  Between 1998 and 2001, we obtained recalled age at menarche, socio-demographic characteristics, and physical activity information in a group of 3206 students at the National University of Colombia who completed a self-administered questionnaire. We examined the cross-sectional associations between mean age at menarche and migratory pattern, parental education, socio-economic status indicators, practice of physical activity, and year of birth using linear regression.
  
  
  RESULTS
  Mean age at menarche (+/- SD) was 12.68 +/- 1.31. In a multivariate adjusted regression model, age at menarche was positively associated with family size and the practice of at least 2 daily hours of physical activity, and was inversely related to urbanization level, socio-economic status, and year of birth.
  
  
  CONCLUSIONS
  Socio-economic status is a strong predictor of menarche in this population. There appears to be a trend towards earlier menarche by year of birth.
authors.affiliation: Harvard School of Public Health, Department of Nutrition, Boston, Massachusetts 02115, USA. jchavarr@hsph.harvard.edu
authors.forename: J
authors.initials: J
authors.lastname: Chavarro
authors.forename: E
authors.initials: E
authors.lastname: Villamor
authors.forename: J
authors.initials: J
authors.lastname: Narváez
authors.forename: A
authors.initials: A
authors.lastname: Hoyos
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D003105:Colombia; D005260:Female; D006801:Humans; D008572:Menarche / Q000502:physiology*; D015999:Multivariate Analysis; D012044:Regression Analysis; D012959:Socioeconomic Factors