title: Is relative leg length a biomarker of childhood nutrition? Long-term follow-up of the Hyderabad Nutrition Trial.
abstract: BACKGROUND
  Relative leg length is frequently used as a biomarker of childhood nutrition in epidemiological studies, but evidence is lacking. We examined the association between supplemental nutrition in pregnancy and childhood and relative proportions of components of height in adolescence.
  
  
  METHODS
  In a community trial of nutritional supplementation, villages from adjacent administrative areas were selected to serve as intervention (n = 15) and control (n = 14) arms. In the intervention villages, balanced protein-calorie supplementation (2.51 MJ, 20 g protein) was offered daily to pregnant women and their offspring until the age of 6 years. Children born in the trial were re-examined 15 years later to assess components of height.
  
  
  RESULTS
  A total of 1165 adolescents (intervention: 654, 49% of trial participants; control: 511, 41% of trial participants) aged 13-18 years were examined. Supplemented children were 10 mm taller [95% confidence interval (CI): 1.4 to 18.7 mm], but almost all of the increase was in trunk length (9 mm, 95% CI: 2.6 to 15.4 mm). The age- and gender-adjusted β-coefficients for the association of nutritional supplementation with relative trunk, leg and lower leg lengths (expressed as standard deviation scores) were 0.26 (95% CI: 0.11 to 0.42), 0.08 (95% CI: -0.03 to 0.19) and 0.03 (95% CI: -0.08 to 0.15) respectively, thereby unsupportive of cephalocaudal gradient in growth.
  
  
  CONCLUSIONS
  In this nutritional supplementation trial in an undernourished population, we were unable to confirm relative leg length as a biomarker of childhood nutrition. Alternative explanations may underlie the reported associations between childhood conditions and relative leg length.
authors.affiliation: Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK. sanjay.kinra@lshtm.ac.uk
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kinra
authors.forename: K V Rameshwar
authors.initials: KV
authors.lastname: Sarma
authors.forename: Michelle
authors.initials: M
authors.lastname: Hards
authors.forename: George Davey
authors.initials: GD
authors.lastname: Smith
authors.forename: Yoav
authors.initials: Y
authors.lastname: Ben-Shlomo
mesh_terms: D000293:Adolescent; D015415:Biomarkers; D001827:Body Height / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D002657:Child Development / Q000502:physiology*; D002664:Child Nutritional Physiological Phenomena; D004044:Dietary Proteins / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007194:India; D007866:Leg / Q000502:physiology*; D008297:Male; D044342:Malnutrition; D015999:Multivariate Analysis; D011247:Pregnancy; D013024:Soybean Oil / Q000008:administration & dosage; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D004044:Dietary Proteins; D013024:Soybean Oil