title: Change in postmenarche anthropometric indicators in indigenous and nonindigenous adolescents from Chile.
abstract: OBJECTIVE
  To analyze the change in anthropometric indicators between menarche and 36 months after menarche among indigenous and non-indigenous adolescents from the Araucanía Region of Chile.
  
  
  METHODS
  This was a concurrent cohort study. Of 8,504 girls interviewed, 114 indigenous adolescents and 123 nonindigenous adolescents who had recently experienced menarche were selected. Body mass index (BMI), BMI by age (BMI z-score), waist circumference (WC) and body fat percentage (BF%) were evaluated at menarche and 6, 12, 18, 24, 30, and 36 months postmenarche. Linear models estimated with generalized estimating equations were used to quantify disparities adjusted for baseline anthropometric values, age at menarche, place of residence, and socioeconomic level.
  
  
  RESULTS
  Indigenous girls presented menarche 4 months later than nonindigenous girls and had significantly higher BMI (1.5 kg/m2), BMI z-score (0.4), WC (2.9 cm), and BF% (1.7%) at menarche. Adjusted results did not show an association between being indigenous and post-menarche anthropometric variables: BMI = 0.1 kg/m2(CI = -0.3; 0.5), BMI z-score = 0 (CI = -0.1; 0.1), WC = 0.7 cm (CI = -0.6; 2.0), and BF% = 0.5% (CI = -0.2; 1.3). It is important to mention that the mean BMI z-score of both groups were in the overweight category.
  
  
  CONCLUSIONS
  At menarche, indigenous girls had higher values than nonindigenous girls for all anthropometric variables, and this trend remained after menarche, with no further change in ethnic disparity over the subsequent three years. This reinforces the need to implement interventions to prevent or control excess weight prior to menarche, with emphasis on indigenous girls.
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, 8380453, Chile.
authors.forename: Macarena
authors.identifier: http://orcid.org/0000-0003-4828-3188
authors.initials: M
authors.lastname: Lara
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, 8380453, Chile.
authors.forename: Patricia
authors.initials: P
authors.lastname: Bustos
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Chile, Santiago, 8380453, Chile.
authors.forename: Hugo
authors.initials: H
authors.lastname: Amigo
mesh_terms: D000293:Adolescent; D000886:Anthropometry; D050218:Body Fat Distribution; D015992:Body Mass Index; D002648:Child; D002677:Chile / Q000453:epidemiology; D005260:Female; D006801:Humans; D007199:Indians, South American; D008137:Longitudinal Studies; D008572:Menarche; D050177:Overweight / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology; D055105:Waist Circumference