The purpose of the study was to examine the relationship and comparisons of athletic amenorrhea and bone mineral density in adolescent, cross-country runners. Subjects: Twenty-eight female adolescent cross-country runners (Mean Age + SD = 15.0 + 1.3 years); consisting of seventeen eumenorrheics & eleven amenorrheics. Design: The design consisted of a sixmonth longitudinal design in which the subjects were measured before and after cross-country season for height, weight, and lean tissue (LT), body fat (BF), bone mineral content (BMC), and bone mineral density (BMD) using whole-body scan densitiometry with a Lunar Dual-energy X-ray Absorptiometer (DXA). Run performance, weekly training volumes, menstrual dysfunction, menarchal age, nutritional information, and stress fractures were reported by the subjects. Statistical analyses consisted of Pearson product-moment and partial correlations to examine the associations of the variables, paired t-tests to measure seasonal body composition changes, multivariate analysis (MANOVA & MANCOVA) to investigate the subgroup differences of variables, and simple linear regression to determine the best body composition predictor variable for BMD. Results: The eumenorrheic subgroup's BMD was significantly greater than the amenorrheic subgroup's BMD (F(1, 54) = 16.22, p<.05, partial h² =.231). The eumenorrheic subgroup's bodyweight (F(1, 54) = 7.65, p<.05, partial h² =.124), BF (F(1, 54) = 8.56, p<.05, partial h² =.137), and BMC (F(1, 54) = 8.52, p<.05, partial h² =.136) were significantly greater than the amenorrheic subgroup. There was also a significant seasonal increase in BMD (t(27) = -4.01, p <.05) for the overall group. Bodyweight was the body composition component that best predicted BMD (F(1, 26) = 46.434, p<.05, R² =.641). There were no significant subgroup differences with respect to run performance, stress fractures, and nutritional supplementation. Conclusions: Athletic amenorrhea was highly associated with lower levels of BMD in adolescent, cross-country runners. Athletic amenorrhea was also highly associated with lower levels of bodyweight, BF, and BMC in adolescent cross-country runners. Finally, cross-country running was highly associated with increased BMD in adolescent athletes. Implications: The long-term implication of the study is that subjects with lower levels of BMD may be at a greater risk of osteoporosis. Recommendations: Educate and instruct runners to utilize proper training methods so the healthful benefits of crosscountry running, as well as improved performance, are obtained.

acase@tulane.edu / 1 / YD

Made available in DSpace on 2014-06-11T19:29:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-15Bitstream added on 2014-06-13T20:20:18Z : No. of bitstreams: 1 cangussu_lm_me_botfm.pdf: 560084 bytes, checksum: e6b5d6f4f10f581592da0884c164a71a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Avaliar a associação entre o equilíbrio postural e a densidade mineral óssea (DMO) em mulheres na pós-menopausa e correlacionar com o risco de quedas. Realizou-se estudo de corte transversal com 225 mulheres, idade 45-75 anos, atendidas em Hospital Universitário. Incluíram-se mulheres em amenorréia >12 meses e idade ≥ 45 anos, com valores de DMO (coluna lombar e colo de fêmur) pelo DXA, dos últimos 12 meses. E se excluíram aquelas com doenças neurológicas ou musculoesqueléticas, história atual de vestibulopatias, déficit visual sem correção, obesidade grau III e usuárias de drogas que alterem o equilíbrio. As mulheres foram divididas segundo a DMO em > -2,0 DP (n=140) e ≤ -2 DP (n=85). Foram analisados o histórico de quedas (últimos 24 meses) e as características clínicas e antropométricas. O equilíbrio postural foi avaliado pela estabilometria (plataforma de força), teste de Romberg, alcance funcional e teste do agachamento. Para análise estatística foram empregados o Teste de Wilcoxon para variáveis quantitativas, o teste do Qui-Quadrado ou Exato de Fisher para variáveis categóricas e o método de regressão logística para o risco de quedas (Odds Ratio-OR). As pacientes com DMO > -2,0 DP eram mais jovens e com menor tempo de menopausa, assim como apresentavam maior IMC e circunferência da cintura quando comparadas aquelas com baixa DMO (≤ -2 DP) (p<0,05). Observou-se que 57,8% (130/225) das participantes relataram episódio de queda nos últimos dois anos, sem diferença significativa na distribuição percentual entre os grupos (p=0,055). Nos parâmetros estabilométricos e no alcance funcional não foram demonstradas diferenças na comparação entre os grupos (p>0,05). No teste de Romberg notou-se aumento progressivo da positividade à medida que aumentava a dificuldade do teste, sendo observada diferença significante entre os grupos apenas com... / To analyze the association between postural balance and bone mineral density (BMD) in postmenopausal women and correlate it with risk for falls. A cross-sectional study was conducted on 225 women aged 45-75 years and cared for at a University Hospital. Women in amenorrhea >12 months and age ≥ 45 years, with BMD values (lumbar spine and femur neck) by DXA for the last 12 months, were included. Those with neurological or musculoskeletal disorders, current history of vestibulopathies, uncorrected visual deficit, level-III obesity or drug use that could affect balance were excluded. The women were divided, according to BMD, in > -2.0 DP (n=140) and ≤ -2 DP (n=85). Histories of falls (last 24 months) as well as clinical and anthropometric characteristics were evaluated. Postural balance was assessed by stabilometry (strength platform), Romberg’s test, functional reach test and the crouching test. For statistical analysis, Wilcoxon’s test was used for quantitative variables, the Chi-square or Fisher’s exact test for categorical variables and the logistic regression method for fall risk (Odds Ratio-OR). Patients with BMD > -2.0 DP were younger and had been menopausal for a shorter period of time; they also showed higher BMI and larger waist circumference as compared to those with low BMD (≤ -2 DP) (p<0.05). It was observed that 57.8% (130/225) of the participants reported fall episodes in the last two years, without significant difference in the percent distribution between the groups (p=0.055). No differences were found in the comparison between the groups (p>0.05) for stabilometric parameters or functional reach test. Concerning Romberg’s test, progressive positive increase was observed as the test difficulty increased, and significant difference between the groups was found only when the women kept their feet in a series and their eyes closed (p<0.05). When evaluating the ... (Complete abstract click electronic access below)

Bone densitometry is the only clinically acceptable and objective method for the accurate measurement of bone mineral density (BMD), bone mass, and the prediction of bone fracture risk. Dual energy X-ray absorptiometry (DXA) is the primary diagnostic bone densitometry tool used in clinical settings. A growing need exists to determine how health care professionals and women use the information obtained from DXA scans in the management of osteoporosis. Few studies have investigated physicians' recommendations and women's compliance related to detection and treatment of osteoporosis after receiving BMD results by DXA. No studies have investigated actions that women have taken after receiving BMD test results conducted by DXA. This descriptive, exploratory study assessed actions that women took and what they perceived their physicians did after receiving BMD results. Using a telephone survey, actions of 138 women, who participated in a previous study of bone health, were evaluated regarding osteoporosis detection, prevention, and treatment. Many women (62%) shared their BMD test results with health professionals. However, 75% of women with low BMD status and who shared their results with health care professionals reported that they did not receive recommendations for advanced tests. Moreover, these women did not receive recommendations for dietary intake changes (60%), medication use (72%), or other lifestyle changes (60%). Yet 58% of these women self-initiated behavioral changes after receiving their BMD test results. Of the women who changed their behaviors, 67% of postmenopausal women increased exercise. Ninety-two percent of these women indicated they would engage in BMD testing again. / Master of Science

Osteoporosis and osteopenia are long-term side effects of bone marrow transplant (BMT). The purpose of this study was to determine the prevalence of bone mineral density (BMD) abnormalities in pediatric patients prior to BMT. Forty-four pediatric patients were evaluated with DEXA scans. The average Z-score was -0.37. Thirty-six percent had abnormal BMD. Sixty-seven percent of ALL patients had abnormal BMD. Patients with non-malignant diseases were significantly more likely to have abnormal BMD. Patients with ALL had more defects than solid tumor patients. Females had more defects than males. These results demonstrate BMD defects are common in children prior to BMT, especially in patients with ALL.

Osteoporosis is a condition involving decreased bone mineral density (BMD) and increased fragility of the skeletal system. Osteoporosis affects ~75 million individuals in the United States, Europe, and Japan. In the United States alone, hip fractures affect 500,000 individuals per year, and annual healthcare costs for osteoporotic fractures are approximately $14 billion. A high peak BMD can prevent or delay the onset of osteoporosis and its complications. Exercise and diet may affect peak BMD by as much as 20 to 40% each and have been identified as the two most important controllable factors determining BMD. The current study investigated the effect of a calcium, vitamin D, and vitamin K supplement combination during initial military cadet exercise training on: BMD, stress fracture occurrence, hormones associated with BMD, and biochemical markers of bone turnover. Significant changes in BMD, either between the supplemented group or the unsupplemented group or across time for both groups were not found. The majority of participants (n = 22) had unexpectedly high levels of physical activity prior to enrollment, and the initial military exercise training program included only moderate levels of activity. Therefore, the exercise stimulus to bone was likely insufficient to promote gains in BMD, regardless of the nutrient supplement status. Serum insulin-like growth factor-1 and osteocalcin significantly increased over time (p < 0.05 and p < 0.001, respectively), irrespective of treatment group. Significant decreases were found in dietary intake of calories (p < 0.01), carbohydrate (p < 0.05), protein (p < 0.0001), and fat (p < 0.01) over time. Decreases in reported dietary intake were likely due to less variety of foods eaten, and diminished compliance with food records. Significant differences were not found between groups or across time in dietary intakes of calcium, vitamin D, or vitamin K. Low dose supplementation with a calcium, vitamin D, vitamin K supplement during initial military training in young-adult cadets did not change BMD or alter stress fracture occurrence. / Master of Science

Osteoporosis is caused by a multitude of factors. An individual’s risk for experiencing a bone fracture as a senior citizen increases without early intervention. Healthcare professionals do not have access to validated survey tools to identify young adults in need of osteoporosis prevention education, although survey tools to identify postmenopausal women at high risk for low bone mass are available. The purposes of this study were to evaluate three of these survey tools for use in a younger population, and to determine if young adults with osteoporosis risk factors received bone health education from a health professional. Forty-two men and 41 women completed surveys and health questionnaires; responses were compared to bone mineral density (BMD) and content (BMC) measurements. Healthcare professionals discussed bone health with only 13% of participants. Chi-square analysis revealed that health professionals were not more likely to discuss osteoporosis with subjects based on age or gender. Participants with T-scores ≤ -1.0 were not more likely to receive bone health education. Area under the receiving operating characteristic (AUROC) curves analysis revealed that no survey tools were able to identify moderate-risk participants at T-scores ≤ -1.0, and AUROC curves for all surveys did not exceed 0.525 at this level. Two surveys detected participants at high risk for bone disease with identical AUROC curves of 0.821 at a T-score ≤ -2.0, and 0.813 at a T-score ≤ -2.5. The AUROC curves indicate that current tools designed for older women do not detect young adults with moderately low T-scores. / Master of Science

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Previous studies suggest that dietary patterns that promote acidosis may have a negative effect on bone density, whereas a more alkaline‐based profile would be associated with better bone health. Thus, the aim of this study was to assess, in omnivores, vegetarians, and vegans bone mineral density using Dual‐energy X‐ray absorptiometry (DEXA) and compare it to their acid‐base status as indicated by urinary pH, Potential Renal Acid Load (PRAL) and serum anion gap. Our hypothesis was that plant‐based diets would be associated with a more alkaline acid‐base profile than omnivorous diets, and thus have a higher bone mineral density. Methods: We conducted a cross‐sectional study where we compared plant based vs. omnivorous diets. Eighty‐two subjects were enrolled in the study (27 omnivores, 27 vegetarians, and 28 vegans). Subjects were asked to fill out a medical history form and a 24‐ hour diet recall, and to complete a 24‐hour urine collection. After a few weeks, subjects returned to the test site to complete a DEXA scan. Acid base‐balance and bone health were determined using PRAL, urine pH, and anion gap as biomarkers for pH, and DEXA as an indicator of bone density. Our results showed that bone mineral density did not differ significantly between groups, although lacto‐ovo and vegan diets were more alkaline compared to meat based diets (6.5  0.4, 6.7  0.4, and 6.2  0.4 pH respectively, p = 0.003). Protein intake was found to be reduced by ~30% in individuals adhering to a lacto‐ovarian or vegan diet; yet protein was only associated with bone mineral density in those following vegan diets. Conversely, urinary pH was associated with bone mineral density only in those following a meat‐based diet. The significance of this study is that it provides knowledge in the area of osteoporosis prevention and perhaps specific recommendations based on diet groups: increased fruit and vegetable intake for those with high meat consumption, to improve the acid‐base homeostasis, and increased plant protein intake for individuals who follow a plant-based diet.

BACKGROUND:Laxatives are among the most widely used over-the-counter medications in the United States but studies examining their potential hazardous side effects are sparse. Associations between laxative use and risk for fractures and change in bone mineral density BMD] have not previously been investigated.METHODS:This prospective analysis included 161,808 postmenopausal women (8907 users and 151,497 nonusers of laxatives) enrolled in the WHI Observational Study and Clinical Trials. Women were recruited from October 1, 1993, to December 31, 1998, at 40 clinical centers in the United States and were eligible if they were 50 to 79 years old and were postmenopausal at the time of enrollment. Medication inventories were obtained during in-person interviews at baseline and at the 3-year follow-up visit on everyone. Data on self-reported falls (greater than or equal to]2), fractures (hip and total fractures) were used. BMD was determined at baseline and year 3 at 3 of the 40 clinical centers of the WHI.RESULTS:Age-adjusted rates of hip fractures and total fractures, but not for falls were similar between laxative users and non-users regardless of duration of laxative use. The multivariate-adjusted hazard ratios for any laxative use were 1.06 (95% confidence interval CI], 1.03-1.10) for falls, 1.02 (95% CI, 0.85-1.22) for hip fractures and 1.01 (95% CI, 0.96-1.07) for total fractures. The BMD levels did not statistically differ between laxative users and nonusers at any skeletal site after 3-years intake.CONCLUSION:These findings support a modest association between laxative use and increase in the risk of falls but not for fractures. Its use did not decrease bone mineral density levels in postmenopausal women. Maintaining physical functioning, and providing adequate treatment of comorbidities that predispose individuals for falls should be considered as first measures to avoid potential negative consequences associated with laxative use.

This dissertation’s three studies investigated the short and long-term relationships of bone-related nutrient intakes with bone mineral density (BMD) in postmenopausal women. This dissertation compared the equivalency of dietary intakes assessed by eight days of diet records (DR) and the Arizona Food Frequency Questionnaire (AFFQ) at one year. It also determined the association of one year (DR) and the average of four-year (AFFQ) dietary intakes with cross-sectional BMD. The dietary intake associations with BMD were further investigated by hormone therapy (HT). Participant’s BMD was measured at the lumbar spine (L2-L4), femur trochanter, femur neck, Ward's triangle and total body using dual energy X-ray absorptiometry. Separate multiple linear regression analysis (p≤0.05), controlled for various covariates, were used to examine the associations between dietary intakes and regional and total body BMD. In study number one (n=266), significant correlations (r=0.30-0.70, p≤0.05) between dietary assessment methods were found with all dietary intake variables. Iron, magnesium, zinc, dietary calcium, phosphorous, potassium, total calcium, and fiber intakes were positively associated with BMD at three or more of the same bone sites regardless of the dietary assessment method at one year. In study number two (n=266), femur trochanter, lumbar spine, and total body BMD had mostly significant inverse associations with dietary polyunsaturated fatty acid (PUFA) intake at one year. In the HT group (n=136), inverse associations with dietary PUFA intake were seen in the spine and total body BMD. In study number three (n=130), average dietary intake of selected bone-related nutrients, were significantly inversely associated with lumbar spine BMD and total body BMD at year four. In the HT group (n=92), inverse associations with dietary PUFA intake were seen in the spine and total body BMD. The DR and AFFQ are acceptable dietary tools used to determine the associations of particular nutrients and BMD sites in healthy postmenopausal women at one year. At one and four year, dietary PUFA intakes had mostly inverse associations with lumbar spine and total body BMD. When categorized by HT use the associations remained significant only in the HT groups, suggesting that HT may influence dietary intake associations with BMD.