Bone Mineral Density in Childhood Study (BMDCS) (Historical/For Reference Only)

Note: This study is complete. The information on this page is provided for historical purposes only. The page is not being updated.

Overview

BMDCS, supported through NICHD's Pediatric Growth and Nutrition Branch, identified predictors of peak bone mass, a major determinant of osteoporosis in later adulthood, enabling practitioners to identify adverse effects of chronic illness on bone.

This multicenter, longitudinal study was performed at five U.S. clinical centers and provided longitudinal measurement of bone mass, linear growth, sexual and skeletal maturation, dietary intake, physical activity, and health history in healthy children.

BMDCS reference curves for bone accrual, bone accretion velocity, and linear growth velocity became the “gold” standard for typical bone accrual. The study also published detailed information about the demographics of study participants, inclusion/exclusion criteria, and study procedures.

Key details about the study and its protocol include the following:

  • Initial enrollment: 1,554 children ages 6 to 16 years
    • Recruitment began in 2002 and ended in 2003
    • Included an equal number of boys and girls
    • Included diverse racial/ethnic groups, with a special focus on enrolling African American children because of racial disparities in bone accrual
    • Provided larger sample sizes in both sexes at ages 6 and 10 years old
  • Wave 2 added 460 children ages 5 to 19 years
    • Recruitment began in 2006 and ended in 2007
  • Five U.S. clinical centers:
    • Children's Hospital of Los Angeles
    • Cincinnati Children's Hospital Medical Center
    • Creighton University (Omaha, NE)
    • Children's Hospital of Philadelphia
    • Columbia University (New York, NY)
  • Additional sites:
    • Dual-energy X-ray absorptiometry (DXA) core laboratory and data coordinating center at the University of California, San Francisco
    • DXA quality assurance office at Wright State University (Dayton, OH)
    • Radiographic core laboratory at Children’s Hospital of Philadelphia
  • Researchers used a Hologic densitometer (QDR4500/Delphi/Discovery models), for measurements, following standardized procedures; results were analyzed centrally.
  • Standard measurements included DXA to measure BMD and bone age, anthropometric assessment (stadiometer height, weight, sitting height), physical exam by an endocrinologist to assess sexual maturation, and nutrition and exercise assessments.
  • In 2010, a genome-wide association study of the BMDCS cohort sought to identify the underlying genetic determinants of peak bone mass and bone mineral accrual in childhood.

Key Findings

  • Bone mineral accretion in childhood occurs at a slow and consistent pace, with a sharp increase during the pubertal growth spurt.
  • Age at onset of puberty was a strong predictor of DXA bone measurements at skeletal maturity, independent of the length of puberty.
  • BMD continues to rise into the third decade of life, even though an individual reaches adult height during late adolescence.
  • Men continue to accrue BMD for several years longer than women.
  • Being White, male, and having a skeletal age of 10 to 14 years were the strongest risk factors for fracture.
  • BMD measures show a high degree of tracking over time. Therefore, a child with low bone density will continue to have low bone density throughout childhood.

Results also revealed the effects of the timing of pubertal onset on bone density, the need for height adjustment of bone density data in children, and the racial disparities in fracture rates in children. (PMID: 21917867)

The study investigators later created a tool to help healthcare providers calculate BMD Z scores for their patients based upon the BMDCS reference data.

More Information

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