Description): Nearly half of peak bone mass (PBM) is acquired during adolescence, making this a critical period to foster bone mineral gains. While genetic factors explain much of the variation in PBM, it is estimated that lifestyle factors can explain up to 40% of the variation. The primary aim of this proposal is to measure the relative contributions of controllable lifestyle factors: intakes of nutrients and supplements, restrained eating practices, physical activity behaviors, smoking behavior, reproductive and contraceptive practices in early, mid and late adolescence, while controlling for genetics, menarcheal age, body composition and weight. Current knowledge of adolescent bone mineral acquisition has been limited by studies with too few subjects or inadequate duration to allow comparison of the effects of behavior at various stages of adolescence on peak bone mass and by the paucity of studies with significant numbers of minority women. This study will avoid these limitations in a cost-effective manner by taking advantage of an extensive and current database on 700 black and white 20-21 year old women followed longitudinally for 10 years in the NHLBI Growth and Health Study (NGHS). Dual energy x-ray absorptiometry (DXA) measurements will be made to assess bone mineral content (BMC), bone mineral density (BMD, BMAD), and bone geometry (hip axis length). Calcaneous ultrasound data will provide additional information on the internal architecture of the bone. Data will also be gathered on vitamin D receptor genotype and current behaviors associated with bone mineral acquisition. A historical cohort design will be employed to provide extensive annual lifestyle data prospectively collected beginning at age 9 years. The study promises to reveal relationships between genetic and lifestyle factors in early, mid and late adolescence and to provide much needed information on the impacts of childhood and adolescent behaviors on skeletal health.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD036590-03
Application #
6181748
Study Section
Special Emphasis Panel (ZHD1-RRG-K (06))
Program Officer
Grave, Gilman D
Project Start
1998-04-01
Project End
2002-03-31
Budget Start
2000-04-01
Budget End
2002-03-31
Support Year
3
Fiscal Year
2000
Total Cost
$194,984
Indirect Cost
Name
University of California Berkeley
Department
Type
Schools of Public Health
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Wang, May C; Crespi, Catherine M (2011) The influence of childhood and adolescent environmental exposure to a westernized environment on the relation between body mass index and adiposity in young Asian American women. Am J Clin Nutr 93:1168S-74S
Wang, M C; Bachrach, L K; Van Loan, M et al. (2005) The relative contributions of lean tissue mass and fat mass to bone density in young women. Bone 37:474-81
Wang, May-Choo; Crawford, Patricia B; Hudes, Mark et al. (2003) Diet in midpuberty and sedentary activity in prepuberty predict peak bone mass. Am J Clin Nutr 77:495-503
Fielding, Krista T; Backrach, Laura K; Hudes, Mark L et al. (2002) Ethnic differences in bone mass of young women vary with method of assessment. J Clin Densitom 5:229-38