May 2008

Document Type


Degree Name



Dept. of Public Health and Preventive Medicine


Oregon Health & Science University


Falls are an important area of interest for the prevention of fractures, injury and disability, but the risk factors for falls are incompletely understood. In evaluating the potential reasons for a fall to occur, various aspects of the diet may play influential roles. Specifically, differential dietary intake of macronutrients such as protein and fat may lead to an increased or decreased risk of falls. Overall diet quality may also be important to fall risk. The purpose of this study is to assess the relationship between dietary intake and falling in women, utilizing a retrospective cohort design. This is a secondary analysis of an existing data set of 87 women, which was previously utilized to evaluate fall and fracture risk between breast cancer survivors and breast cancer free controls. As such, a large portion (56 / 87, 64%) of this cohort consists of recent breast cancer survivors. Breast cancer survivors were 3-15 months post-chemotherapy at enrollment, and all women were pre-menopausal at either diagnosis or enrollment. No new information was gathered for the purpose of this analysis. The primary outcome of interest in this study is self-reported falls over the course of one year, recorded monthly. Dietary information was obtained at enrollment using the Block98 Food Frequency Questionnaire (FFQ). Various demographic, laboratory, and history information were also taken for evaluation of potential confounders. Cross tabulation and multivariate regression procedures were used to evaluate the associations of interest. In order to obtain relative risk (RR) estimates, log-binomial regression was utilized in the SAS software package. Variables of interest, potential covariates, and potential confounders were all analyzed through the model-building process. Separate models were built for fat, protein, carbohydrates, and a measure for overall diet quality, the Healthy Eating Index score (HEI score). Several trends were evident after modeling, though none reached statistical significance. For percentage of calories from fat, the women who consumed the highest tertile of percentage of calories from fat were at greater risk of falling compared to the lowest tertile (RR 1.45, 95% Confidence Interval (CI): 0.89 – 2.36), while the women who consumed the middle tertile had the same risk of falling compared to those in the lowest tertile (RR 1.01, 95% CI: 0.56 – 1.80). The women who consumed the highest tertile of percentage of calories from protein were at a slightly increased risk of falling compared to those in the lowest tertile (RR 1.06, 95% CI 0.60 – 1.85), while the women who consumed the middle tertile were at a reduced risk compared to the women in the lowest tertile (RR 0.84, 95% CI 0.52 – 1.33). Thus it appears that women who consume greater than 42.5% of their calories from fat are at increased risk of falls, while those who eat a moderate amount of protein (14.5-16.5% of calories) are at decreased risk. These trends may be useful in providing a basis for future research where a larger sample size may provide more statistically significant results.




School of Medicine



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