title: Normative data and percentile curves of bone mineral density in healthy Iranian children aged 9-18 years.
abstract: We provide the first reference values for bone mineral content and bone mineral density according to age and sex in Iranian children and adolescents. The prevalence of hypovitaminosis D was high, and levels of physical activity were low in our sample. Multiple regression analyses showed age, BMI, and Tanner stage to be the main indicators of bone mineral apparent density.
  
  
  OBJECTIVE
  Normal bone structure is formed in childhood and adolescence. The potential determinants which interact with genetic factors to influence bone density include gender, nutritional, lifestyle, and hormonal factors. This study aimed to evaluate bone mineral content (BMC) and the bone mineral density (BMD) and factors that may interfere with it in Iranian children.
  
  
  METHODS
  In this cross-sectional study, 476 healthy Iranian children and adolescents (235 girls and 241 boys) aged 9-18 years old participated. BMC and BMD of the lumbar spine, femoral neck, and total body were measured by dual-energy X-ray absorptiometry using a Hologic Discovery device, and bone mineral apparent density (BMAD) of the lumbar spine and the femoral neck were calculated.
  
  
  RESULTS
  We present percentile curves by age derived separately for BMC, BMD, and BMAD of the lumbar spine, left femoral neck, and total body excluding the head for boys and girls. Maximum accretion of BMC and BMD was observed at ages of 11-13 years (girls) and 12-15 years (boys).The prevalence of hypovitaminosis D was high and physical activity was low in our participants. However, in multiple regression analyses, age, BMI, and Tanner stage were the main indicators of BMD and BMAD                                CONCLUSION:                  These normative data aid in the evaluation of bone density in Iranian children and adolescents. Further research to evaluate the evolution of BMD in Iranian children and adolescents is needed to identify the reasons for significant differences in bone density values between Iranian populations and their Western counterparts.
authors.affiliation: Endocrine and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Marjan
authors.initials: M
authors.lastname: Jeddi
authors.forename: Mohammad Jafar
authors.initials: MJ
authors.lastname: Roosta
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Dabbaghmanesh
authors.forename: Gholamhossein Ranjbar
authors.initials: GR
authors.lastname: Omrani
authors.forename: Sayed Mohammad Taghi
authors.initials: SM
authors.lastname: Ayatollahi
authors.forename: Zahra
authors.initials: Z
authors.lastname: Bagheri
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Showraki
authors.forename: Marzieh
authors.initials: M
authors.lastname: Bakhshayeshkaram
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D012016:Reference Values; D012044:Regression Analysis