The Bone Mineral Density in Childhood Study (BMDCS) is a multi-center longitudinal study examining bone accretion (BMD by DXA) in a racially diverse cohort of 2014 healthy boys and girls (1022 female) ages 5 to 20 years. BMDCS cohort represents healthy children with height, weight, and body mass index (BMI) between the 3rd and 97th percentile and no previous or current conditions that might affect bone acquisition. The subjects were evaluated annually for up to 6 years (7 visits). Subjects were recruited in two phases: 1554 healthy boys and girls ages 6 to 17 years were enrolled from July 2002 to November 2003 at five medical centers in the U.S. A second recruitment wave occurred between 2006 and 2007 to increase the number of younger (5 y) and older (19 y) participants to extend the reference percentiles from ages 5 to 20 years. The second wave of participants were followed for 2 years (3 visits). Study participants were classified as African American or non-African American based on parental report of the child's ancestry.
DXA scans were obtained using Hologic, Inc. (Bedford, MA) bone densitometers (QDR4500A, QDR4500W, Delphi A and Apex models). One densitometer was used at each Clinical Center. The acquisition software versions varied slightly from version 11.1 to 12.7 (Apex 2.1).
The BMDCS was initiated in 2001 by its program director, Karen Winer, M.D., and funded by the NICHD (Pediatric Growth Nutrition Branch). Children were recruited from five Clinical Centers in the United States: Children's Hospital of Los Angeles (Los Angeles, CA), Cincinnati Children's Hospital Medical Center (Cincinnati, OH), Creighton University (Omaha, NE), Children's Hospital of Philadelphia (Philadelphia, PA), and Columbia University (New York, NY). The study included a DXA analysis and coordinating center at UC-SF (San Francisco, CA). A full description of the protocol and results of the study can be found in the BMDCS publications (see bibliography).