Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / School of Physical Education, Sport, and Exercise Science

The primary purpose of this research study was to cross-validate the risk factors in the Osteoporosis Risk Assessment by Composite Linear Estimate [ORACLE] as a screening tool in a population of healthy U.S. women at various menopausal stages. The secondary purpose of this study was to evaluate the potential use of physical activity history and relevant osteoporosis risk factors to effectively determine current bone status for a mixed menopausal population. Third, the purpose of this study was to compare Omnisense quantitative ultrasound [QUS] and dual-energy x-ray absorptiometry [DXA] diagnostic values of osteopenia/osteoporosis based upon T- and Z-scores. Methods: Fifty-six female subjects (46.1 ± 6.3 years) in pre-, peri-, and post-menopausal stages who volunteered to participate in this study. Subjects completed an osteoporosis risk factor and physical activity history questionnaire. Subjects underwent laboratory testing comprised of distal radius quantitative ultrasound scan, dual hip and spine DXA scans, and a one week physical activity assessment. Results: Logistic regression analysis was utilized to examine the ability of the ORACLE to predict low BMD at the femoral neck and lumbar spine. There were no significant relationships between the group of ORACLE variables and BMD status at either the femoral neck or lumbar spine. In addition, none of the individual variables (age, BMI, use of HRT therapy, previous fracture, speed of sound [SOS]) were found to be significant predictors of low BMD at the femoral neck or lumbar spine. Notably, SOS measures from the Omnisense QUS were not found to have a strong positive predictive ability, with sensitivity values between 0-20% and specificity values between 81-86% at the femoral neck and lumbar spine. When the cohort was divided into normal and overweight/obese groups, sensitivity and specificity of QUS measures was not improved in the normal BMI group compared to the overweight/obese group. The use of physical activity variables to predict low BMD revealed some relationships trending toward significance, supporting previous research. Linear regression analyses revealed that the individual accelerometry variable of moderate-vigorous non-bout activity counts at the lumbar spine approached significance as a predictor of low BMD (p = 0.081). A significant correlation (r = 0.31, p < 0.05) between steps/day and subjective measures of current weight-bearing activity support the validity of the physical activity recall method for current physical activity. Conclusions: This study found that the ORACLE risk factors were not a valid osteoporosis screening tool in a mixed menopausal population of U.S. women. Secondarily, subjective and objective physical activity measures were non-significant predictors of current low BMD, but greater levels of moderate to vigorous non-bout activity counts trend towards being a significant predictor of higher BMD at the lumbar spine. Finally, results showed that Omnisense QUS measures were not found to be significantly related to DXA measures. Key Words: bone mineral density, dual-energy x-ray absorptiometry, osteoporosis, physical activity, quantitative ultrasound. / School of Physical Education, Sport, and Exercise Science

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / School of Physical Education, Sport, and Exercise Science

The purpose of this paper is the development of a model to investigate possible causal relationships among some of the commonly reported risk factors for the development of osteoporosis and consequential hip fracture. Comparison of hip fracture incidence between women of primarily European descent, referred to in the literature as Caucasians, and Japanese women is made. Studies report the incidence of hip fractures among Japanese women is lower than among Caucasian women. Numerous factors related to the development of osteoporosis are significantly different between Japan and the United States. The model helps explain the interrelationships among the variables involved in this observed geographical variation in hip fracture incidence. / Department of Anthropology

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