Osteoporosis is a skeletal disease affecting 44 million Americans. A primary strategy to
prevent osteoporosis is to develop a high peak bone mass in youth. Oral Contraceptives
(OCs) alter hormones in women and could affect bone mass development. The
interaction between OCs and skeletal mineralization is poorly understood. PURPOSE:
Our aims were to 1) compare bone mineral density (BMD) of young women who had a
history of OC use with regularly menstruating controls, 2) compare changes in BMD in
controls, women who initiate OC use, and those who have a history of use, and 3) to
evaluate predictive capabilities of physical activity and years of oral contraceptives use
on changes in BMD. METHODS: We recruited women, 18 to 25 years of age, with a
history of OC use and controls. BMD at the hip, whole-body, and spine (AP, g/cm�� and
width-adjusted lateral, g/cm��) was measured by dual-energy x-ray absorptiometry.
Physical activity (METs) was measured via questionnaire and grip strength was evaluated using an isometric dynamometer. RESULTS: Groups were similar in body mass index
(BMI), fat mass, grip strength, calcium intake and physical activity but controls were
slightly older than OC users. In analysis of covariance (ANCOVA), controlling for age
and BMI, controls had significantly greater BMD than OC users at baseline at the AP and
lateral spine, hip, and whole-body (p<0.05). By ANCOVA (covariates = age at baseline,
change in weight), oral contraceptive users had greater bone loss at L��� in the lateral view
than controls whereas, controls had greater increases in L��� volumetric BMD, BMD of the
total hip, and whole body than OC users (p<0.05). Stepwise regression results did not
reveal years of oral contraceptive use, grip strength, or METs to be a significant predictor
of changes in BMD at any site. CONCLUSIONS: We conclude that, in the cross-sectional
analysis, oral contraceptive use by young women may compromise bone health
during a time when mineral is still accruing. In the prospective analysis, regularly
menstruating controls had greater BMD accrual or less bone loss over a 12-month time
period than women with a history of oral contraceptive use. / Graduation date: 2005
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31808 |
| Date | 19 April 2005 |
| Creators | Almstedt Shoepe, Hawley Chase |
| Contributors | Snow, Christine M. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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