title: Adiposity and bone health in Spanish adolescents. The HELENA study.
abstract: While the association of lean mass (LM) with bone mass is well understood, the association of fat mass (FM) with bone mass is controversial. Our results support that adolescents with higher levels of adiposity have greater bone mass, but this association is fully explained by their higher levels of LM.
  
  
  BACKGROUND
  We aimed (1) to study the independent association of FM and LM with bone mass and (2) to study the differences in bone mass by weight status in adolescents, after controlling for relevant confounders, such as physical activity (PA), calcium intake, and LM.
  
  
  METHODS
  Participants were 330 adolescents (167 boys, 12.5-17.5 years) from the HELENA study. The relationships of FM (DXA, n = 330; BodPod, n = 282) and LM (DXA, n = 330) with different bone variables (whole body, total hip, lumbar spine, and femoral neck) were analyzed by linear regression, and differences between weight status were analyzed by ANCOVA.
  
  
  RESULTS
  Fat mass (DXA) was positively associated with bone variables in both sexes, after adjustment for height, calcium intake, and sexual maturation. Additional adjustment by PA slightly increases the associations. However, adjustment for LM inverted these associations. Similar results were obtained using BodPod instead of DXA for assessing FM. Overweight/obese adolescents had higher BMC than their non-overweight peers in most of regions studied. Additional adjustment for PA slightly increased the differences between weight status groups, while adjusting for LM inverted the associations. LM was strong and positively associated with all bone variables in both sexes. Additional adjustment for PA or FM did not change the results.
  
  
  CONCLUSIONS
  Adolescents with higher levels of adiposity have greater bone mass, but this association is explained by their higher levels of LM.
authors.affiliation: GENUD Growth, Exercise, Nutrition and Development Research Group, University of Zaragoza, 50009 Zaragoza, Spain. lgracia@unizar.es
authors.forename: L
authors.initials: L
authors.lastname: Gracia-Marco
authors.forename: F B
authors.initials: FB
authors.lastname: Ortega
authors.forename: D
authors.initials: D
authors.lastname: Jiménez-Pavón
authors.forename: G
authors.initials: G
authors.lastname: Rodríguez
authors.forename: M J
authors.initials: MJ
authors.lastname: Castillo
authors.forename: G
authors.initials: G
authors.lastname: Vicente-Rodríguez
authors.forename: L A
authors.initials: LA
authors.lastname: Moreno
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D050154:Adiposity / Q000502:physiology*; D000293:Adolescent; D000886:Anthropometry / Q000379:methods; D015992:Body Mass Index; D015519:Bone Density / Q000502:physiology*; D002136:Calcium, Dietary / Q000008:administration & dosage; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005272:Femur Neck / Q000502:physiology / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology / Q000503:physiopathology; D008297:Male; D009043:Motor Activity / Q000502:physiology; D050177:Overweight / Q000503:physiopathology; D012727:Sex Characteristics; D013030:Spain
chemical_list: D002136:Calcium, Dietary