This proposal is founded upon: 1) the recognition that bone density acquired early in life is a predictor of osteoporosis risk, 2) recognition that peak bone density in women is achieved during the second decade of life, and 3) our current observation that 19 year old women who have been menstrually irregular during their teenage years have significantly lower trabecular bone density than their eumenorrheic classmates. Additional findings which support the concept that maturational events during puberty can affect women's health status decades later include: a documented decrease in adolescent calcium intake, a decrease in adolescent exercise, and linear premenopausa bone loss. Since premenopausal bone loss appears to be influenced by sex steroid status, diet and exercise, we propose a longitudinal study to determine the roles played during adolescence by integrated estrogen status, calcium intake, and exercise upon the timing and magnitude of peak bone density accretion in adolescent women. We propose a five year study of 100 closely matched Caucasian school girls who will be 11 years of age at entry. Fifty of the study group will be given a 600 mg per day calcium supplement by a double-blind design. Each subject will be seen every six months at which time integral vertebral and cortical radial bone density will be measured. Investigations of determinants of bone density in young women have been limited due to the radiation exposure associated with previously available instrumentation necessary to obtain quantitative measurement of ben density. A recent advance in bone measurement technology, x-ray absorptiometry (XRA), in now available and is well suited for studies involving children because of the extremely low radiation used. Nutrition profiles will be obtained from three day diet diaries and exercise patterns from activity surveys. We will measure integrated estrogen exposure by evaluating pubertal progression based on developmental landmarks in addition to sex steroid and gonadotropin profiles obtained from urine specimens. Statistical analysis of the continuous study variables will allow us to determine whether these variables affect peak bone accretion in young girls independently or in a concerted fashion. The results of this study will provide information to be used in the prevention of osteoporosis in American women.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
1R01HD025973-01
Application #
3327275
Study Section
Reproductive Endocrinology Study Section (REN)
Project Start
1989-12-01
Project End
1994-11-30
Budget Start
1989-12-01
Budget End
1990-11-30
Support Year
1
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Pennsylvania State University
Department
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Devlin, M J; Stetter, C M; Lin, H-M et al. (2010) Peripubertal estrogen levels and physical activity affect femur geometry in young adult women. Osteoporos Int 21:609-17
Petit, Moira A; Beck, Thomas J; Hughes, Julie M et al. (2008) Proximal femur mechanical adaptation to weight gain in late adolescence: a six-year longitudinal study. J Bone Miner Res 23:180-8
Lloyd, Tom; Petit, Moira A; Lin, Hung-Mo et al. (2004) Lifestyle factors and the development of bone mass and bone strength in young women. J Pediatr 144:776-82
Petit, Moira A; Beck, Thomas J; Lin, Hung-Mo et al. (2004) Femoral bone structural geometry adapts to mechanical loading and is influenced by sex steroids: the Penn State Young Women's Health Study. Bone 35:750-9
Legro, Richard S; Lin, Hung Mo; Demers, Laurence M et al. (2003) Urinary free cortisol increases in adolescent caucasian females during perimenarche. J Clin Endocrinol Metab 88:215-9
Lloyd, Tom; Lin, Hung Mo; Matthews, Amy E et al. (2002) Oral contraceptive use by teenage women does not affect body composition. Obstet Gynecol 100:235-9
Lloyd, Tom; Lin, Hung Mo; Eggli, Douglas F et al. (2002) Adolescent Caucasian mothers have reduced adult hip bone density. Fertil Steril 77:136-40
Lloyd, T; Beck, T J; Lin, H-M et al. (2002) Modifiable determinants of bone status in young women. Bone 30:416-21
Lloyd, T; Taylor, D S; Lin, H M et al. (2000) Oral contraceptive use by teenage women does not affect peak bone mass: a longitudinal study. Fertil Steril 74:734-8
Legro, R S; Lin, H M; Demers, L M et al. (2000) Rapid maturation of the reproductive axis during perimenarche independent of body composition. J Clin Endocrinol Metab 85:1021-5

Showing the most recent 10 out of 20 publications