This study was designed to investigate the relationship between retinol
intake, bone mineral density, and falls in 101 elderly women aged 72 to 90
years (78.6 yrs. �� 4.3 yrs.). Bone mineral density (BMD) (g/cm��) of the
left hip, anterior-posterior lumbar spine (L3), and lateral spine (L3) was
measured using dual-energy x-ray absorptiometry. Dietary intake and
physical activity were assessed by validated questionnaires (the 100-item
Block Food Frequency Questionnaire and the Physical Activity Scale for
the Elderly, respectively). Isometric hip abduction strength of the right
and left legs was assessed using a hand-held dynamometer. Fall
surveillance was collected using a "postcard" system at three-month
intervals over a two-year period. Multiple regression analyses were used
to show the predictability of retinol, vitamin D, calcium, years past
menopause, years on hormone replacement therapy, and physical activity
on BMD variables. Together, these variables explained 14% of the
variance in total hip BMD at follow-up (R��=0.14, SEE=0.12, p=0.020),
26% of the variance in the anterior-posterior spine BMD at follow-up
BMD (R��=0.26, SEE=0.17, p=0.051), and 33% of the variance in lateral
spine BMD at follow-up (R��=0.33, SEE=0.10, p=0.009). Two-year
changes in hip BMD were poorly predicted using the model with only 5%
of total hip BMD variance being explained by the six independent
variables (R��=0.05, SEE=0.03, p=0.558). Logistic regression was used
to determine whether the likelihood of being a faller vs. a non-faller could
be predicted from a model using retinol, vitamin D, average hip strength,
and physical activity. It was shown that 11.5% of the variability in fall
status could be explained by the model (Cox & Snell's R��=0.115). Using
an ROC curve analysis, the model correctly classified 69% of the
individuals into the correct "fall category". We conclude that retinol,
although not an independent predictor of BMD or fall status, is an
important component in the prediction of both BMD and falls. Further
interventional research is needed to determine the effects of retinol on
BMD and falling. / Graduation date: 2004
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/30144 |
| Date | 20 November 2003 |
| Creators | Gramer, Carrie M. |
| Contributors | Gunter, Katherine B., Snow, Christine M. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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