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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Prevalência e fatores de risco para fraturas vertebrais em idosos da comunidade / Prevalence and risk factors of vertebral fractures in communitydwelling elderly

Lopes, Jaqueline Barros 08 January 2010 (has links)
Objetivo: Estimar a prevalência de fraturas vertebrais investigando os fatores de risco associados com esta última condição em idosos brasileiros da comunidade. Métodos: Este estudo de corte transversal incluiu 769 indivíduos idosos com 65 anos ou mais (462 mulheres e 307 homens) residentes em São Paulo, Brasil. Radiografias de coluna torácica e lombar foram obtidas e fraturas vertebrais foram avaliadas usando o método semiquantitativo de Genant. Densidade mineral óssea (DMO) foi mensurada por DXA e parametros bioquímicos foram também avaliados. Mulheres e homens foram analisados separadamente, e cada gênero foi dividido em 2 grupos com base na presença de fraturas vertebrais. Resultados: A prevalência de fraturas vertebrais foi de 16,7% (95% CI 13,3-20,1) nas mulheres e 21,2% (95% CI 16,6-25,7) nos homens. Análise de regressão logística usando as variáveis significantes na análise univariada no grupo feminino mostrou que a idade (OR=1,12, 95% CI 1,06-1,18; p<0,001) e o Tscore do colo femoral (OR=0,61, 95% CI 0,46-0,88; p=0,006) foram fatores de risco independentes na predição de fraturas vertebrais. No grupo masculino, a análise de regressão logística demonstrou que a condição de caidor crônico (OR=2,54 95% CI 1,1-5,9; p=0,031) e T-score do colo femoral (OR=0,72, 95% CI 0,53-0,96; p=0,025) foram independentes parâmetros na predição de fraturas vertebrais. Conclusão: Nossos resultados sugerem que fraturas vertebrais são comuns em idosos brasileiros e que o T-score do colo femoral baixo foi um importante fator de risco para esta condição em ambos homens e mulheres. Idade também foi significantemente correlacionada com a presença de fraturas vertebrais em mulheres, e a condição de caidor crônico foi correlacionada com fraturas vertebrais em homens. / Purpose: To estimate the prevalence of radiographic vertebral fracture and investigate factors associated with this condition in Brazilian communitydwelling elderly. Methods: This cross sectional study included 769 elderly subjects 65 years old and over (462 women and 307 men) living in São Paulo, Brazil. Thoracic and lumbar spine radiographs were obtained and vertebral fractures were evaluated using Genant´s semi-quantitative method. Bone mineral density (BMD) was measured by DXA and bone biochemical markers were also evaluated. Female and male subjects were analyzed independently, and each gender was divided into 2 groups, based on whether vertebral fractures were present. Results: The prevalence of vertebral fracture was 16.7% (95% CI 13.3-20.1) in women and 21.2% (95% CI 16.6-25.7) in men. Logistic regression analyses using variables that were significant in the univariate analysis, in female group showed that age (OR=1.12, 95% CI 1.06-1.18; p<0.001) and femoral neck T-score (OR=0.61, 95% CI 0.46-0.88; p=0.006) were independently factors in predicting vertebral fracture. In the male group, logistic regression analyzes demonstrated that chronic faller condition (OR=2.54 95% CI 1.1-5.9; p=0.031) and femoral neck T-score (OR=0.72, 95% CI 0.53-0.96; p=0.025) were independent parameters in predicting vertebral fractures. Conclusions: Our results suggest that radiographic vertebral fractures are common in Brazilian community-dwelling elderly and that a low femoral neck T-score was an important risk factor for this condition in both males and females. Age was also significantly correlated with the presence of vertebral fractures in women, and chronic faller was correlated with vertebral fractures in men.
122

Densidade mineral óssea alta em mulheres na pós menopausa: fatores determinantes / High bone mineral density in postmenopausal women: determinant factors

Pippa, Maria Guadalupe Barbosa 02 December 2009 (has links)
O conceito de densidade mineral óssea alta (DMOAL) é controverso, e valores diferentes de DMO têm sido considerados como limite para essa classificação. Considerando que DMOAL pode estar presente em indivíduos normais e anormais, é importante analisar os possíveis fatores clínicos determinantes desta condição. Estudamos 337 mulheres pós-menopausa (180 com DMOAL e 157 grupo controle). A tecnologia DXA foi usada para medir a DMO e os compartimentos da composição corpórea. O grupo DMOAL tinha que apresentar DMO areal com valores absolutos 1,228 g/cm 2 (L1-L4) e 1,006 g/cm 2 (colo do fêmur). Além disso, o T-score deveria ser 0,1 SD (OMS) e o percentil do índice T > 100% em todos os sítios (L1, L2, L3, L4, L1-L4, DP colo do fêmur (CF) wards, trocanter e fêmur total (FT). As pacientes que não apresentavam estes critérios foram incluídas no grupo controle (GC). Todas as voluntárias realizaram testes laboratoriais e responderam questionário de Baecke para avaliar atividade física. A correlação entre as variáveis foram estimadas (coeficiente de correlação de Pearson, Deviance and Hosmer Lemeshow). Modelos de regressão múltipla foram usados para identificar os preditores independentes determinantes de DMOAL. Resultados: A média de idade no grupo DMOAL foi de 60 anos (DP = 8,3); peso 77,0 kg (DP = 11,7); altura 1,57 cm (DP = 0,05) e IMC 31,1 kg/m 2 (DP = 4,9). O não uso prévio de terapia de reposição hormonal (TRH) mostrou correlação negativa com DMOAL no colo do fêmur (r 2 = - 0,011) e o estado eutireoideo mostrou um possível efeito protetor e mantenedor nos valores de DMO . Pacientes com DMOAL em fêmur total não apresentavam antecedentes de fratura prévia por fragilidade (r 2 = 0,008). Valores normais de VB12 mostraram correlação positiva com DMOAL (r 2 = 0,098). O mesmo aconteceu para valores normais ou elevados de leptina. Pacientes com baixa atividade física apresentaram correlação inversa com DMOAL. Estes resultados sugerem que o uso prévio de TRH, estado eutireóideo, uso atual de sinvastatina, e altos níveis de leptina podem ser importantes para a manutenção de DMOAL. Interessantemente, quando utilizamos o cutoff >1 DP para determinar as mulheres com DMOAL nos sítios já referidos, usando este mesmo banco de dados, observamos que para cada aumento de 1 kg de massa magra, a chance de apresentar DMOAL aumentou em 15%. Além disso, o hábito de não fumar, aumentou em 4,21 vezes a chance de apresentar DMOAL. Finalmente, observamos que a massa magra total manteve sua influência positiva na DMO, mesmo quando usamos um valor de corte (cutoff) 1,5 DP no colo do fêmur e fêmur total, como critério de seleção de DMOAL / The concept of high bone mineral density (HBMD) is controversial and different values of BMD have been considered as threshold for this classification. Whereas HBMD may be present in normal and abnormal, it is important to analyze the possible factors determining this clinical condition. We studied 337 postmenopausal women (180 with HBMD and 157 control group). DXA technology was used to measure BMD and body composition compartments. The group HBMD had to present areal BMD with absolute values 1.228 g/cm 2 (L1-L4) and 1.006 g/cm 2 (femoral neck). Moreover, the T-score should be 0,1 SD (WHO) and the percentile of the index T >100% at all sites (L1, L2, L3, L4, L1-L4, Femoral neck, wards, trochanter and Total femur). The patients without these criteria were included in the control group (CG). All volunteers performed laboratory tests and answered the Baecke Questionnaire to assess physical activity. The correlation between variables were estimated (correlation coefficient of Pearson, Deviance and Hosmer- Lemeshow test). Multiple regression models were used to identify independent predictors determinants HBMD. Results: The mean age in group HBMD was 60 years (SD = 8.3), weight 77.0 kg (SD = 11.7), height 1.57 cm (SD = 0.05) and BMI 31,1 kg/m 2 (SD = 4.9). Non prior using of hormone replacement therapy (HRT) showed negative correlation with HBMD in femoral neck (r 2 = - 0.011) and euthyroid state seemed to favor and to maintain HBMD on this site. Patients with negative history of previous fracture fragility had HBMD in total femur (r 2 = 0.008). Normal values of vitamin B12 showed positive correlation with HBMD (r 2 = 0.098). The same occurred for normal or high levels of leptin. Patients with low physical activity correlated inversely with HBMD. Our results suggest that previous use of HRT, euthyroid state, current use of simvastatin, and high levels of leptin may be important to maintaining HBMD. Interestingly, when we used the cutoff >1 SD to determine HBMD women on the sites already mentioned, using this same database, we found that for each increase of 1 kg of lean body mass, the chance of presenting HBMD increased by 15%. Yet, the habit of not smoking, increased by 4.21 times the chance of having HBMD. Finally, we observed that the total lean mass maintained its positive influence on BMD, even when using a cutoff value 1.5 SD in femoral neck and total femur as a criterion of selection for HBMD
123

Avaliação genética de pacientes com osteoporose /

Tayar, Giullianna January 2006 (has links)
Resumo: A osteoporose é uma doença metabólica, que se caracteriza por baixa massa e deterioração do tecido ósseo, conduzindo à fragilidade do osso com conseqüente aumento do risco de fraturas. O início da doença é influenciado por uma complexa interação entre fatores genéticos e ambientais, que pode afetar diferentemente os indivíduos. Por essa razão, faz-se necessário o estudo dos polimorfismos dos genes associados ao metabolismo ósseo, como os do Receptor para Vitamina D (VDR) e da Apolipoproteína E (APOE), além dos envolvidos no biometabolismo de agentes ambientais, como as Glutatião-S-Transferases (GSTs). Foram estudados 53 pacientes, homens e mulheres, com osteoporose e ou osteopenia, pareados por sexo e faixa etária com um grupo controle. O DNA foi extraído de leucócitos de sangue periférico e amplificado por Reação em Cadeia da Polimerase (PCR). Os polimorfismos GSTM1 e GSTT1 foram analisados em gel de agarose 2%, enquanto os da APOE e VDR foram submetidos à restrição enzimática com as enzimas Hha I e Fok I, respectivamente, seguido da análise em gel de poliacrilamida 6%, corados com brometo de etídeo e visualizados em luz UV. A análise estatística dos dados foi realizada, utilizando-se o teste t, teste de Fisher, a regressão multivariada e o teste de equilíbrio de Hardy-Weinberg. O genótipo nulo (0/0) de GSTM1 mostrou-se significantemente mais freqüente nos pacientes (64,1%) comparado ao dos controles (37,7%; P= 0,00112). Por outro lado, pacientes e controles não diferiram quanto à presença (+/+) e ausência (0/0) do gene GSTT1 (P=0,5328). A distribuição genotípica do polimorfismo VDR - Fok I revelou freqüência significantemente aumentada do genótipo ff nos pacientes (22,6%; P=0,0078). Para o gene da APOE, o alelo e3 foi significantemente mais freqüente nos controles (0,85; P=0,0431), enquanto...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Osteoporosis is a metabolic disease characterized by low body mass and bone deterioration, leading to bone fragility with the consequent increase of fractures risk. The disease onset is influenced by a complex interaction between genetic, and environment factors that can affect differently the individuals' response. Therefore, the study of polymorphisms regarding the genes involved in bone metabolism is of upgrade necessity, such as the Vitamin D Receptor gene (VDR), Apolipoprotein E (APOE), besides the genes involved in xenobiotic metabolism, it means, the Glutathion-S-Transferases (GSTs). We have studied 53 patients, men and women, with osteoporosis and/or osteopenia, matched by gender and age with a control group. The DNA was extracted from peripheral blood lymphocytes and amplified through Polimerase Chain Reaction (PCR). GSTM1, and GSTT1 polymorphisms were analyzed in 2% agarose gel, while APOE, and VDR had been submitted to enzymatic restriction with Hha I and Fok I enzymes, respectively, followed by the analysis in 6% polyacrilamide gel, stained with ethidium bromide and visualized under UV light. The statistic analysis was carried on using test t, test of Fisher, the multi-varied regression and the test of Hardy-Weinberg balance. The GSTM1 null genotype (0/0) was significantly more frequent in patients (64.1%) compared to the controls (37.7%; P= 0.00112). On the other hand, patients, and controls did not differ concerning the presence (++) and absence (0/0) of GSTT1 gene (P=0.5328). The genotypic distribution of VDR -Fok I polymorphism showed a significantly increased frequency of the genotype ff in patients (22.6%; P=0.0078). For the APOE, the allele e3 was significantly more frequent in controls (0.85; P=0.0431), while the allele e4 was in patients (0.20; P=0.0075). The genotype...(Complete abstract click electronic access below) / Orientador: Nívea D T Conforti Froes / Coorientador: Dorotéia Rossi Silva / Banca: Adriana Madeira Alvares da Silva / Banca: Eny Maria Goloni Bertollo / Mestre
124

Prevalência e fatores de risco para fraturas vertebrais em idosos da comunidade / Prevalence and risk factors of vertebral fractures in communitydwelling elderly

Jaqueline Barros Lopes 08 January 2010 (has links)
Objetivo: Estimar a prevalência de fraturas vertebrais investigando os fatores de risco associados com esta última condição em idosos brasileiros da comunidade. Métodos: Este estudo de corte transversal incluiu 769 indivíduos idosos com 65 anos ou mais (462 mulheres e 307 homens) residentes em São Paulo, Brasil. Radiografias de coluna torácica e lombar foram obtidas e fraturas vertebrais foram avaliadas usando o método semiquantitativo de Genant. Densidade mineral óssea (DMO) foi mensurada por DXA e parametros bioquímicos foram também avaliados. Mulheres e homens foram analisados separadamente, e cada gênero foi dividido em 2 grupos com base na presença de fraturas vertebrais. Resultados: A prevalência de fraturas vertebrais foi de 16,7% (95% CI 13,3-20,1) nas mulheres e 21,2% (95% CI 16,6-25,7) nos homens. Análise de regressão logística usando as variáveis significantes na análise univariada no grupo feminino mostrou que a idade (OR=1,12, 95% CI 1,06-1,18; p<0,001) e o Tscore do colo femoral (OR=0,61, 95% CI 0,46-0,88; p=0,006) foram fatores de risco independentes na predição de fraturas vertebrais. No grupo masculino, a análise de regressão logística demonstrou que a condição de caidor crônico (OR=2,54 95% CI 1,1-5,9; p=0,031) e T-score do colo femoral (OR=0,72, 95% CI 0,53-0,96; p=0,025) foram independentes parâmetros na predição de fraturas vertebrais. Conclusão: Nossos resultados sugerem que fraturas vertebrais são comuns em idosos brasileiros e que o T-score do colo femoral baixo foi um importante fator de risco para esta condição em ambos homens e mulheres. Idade também foi significantemente correlacionada com a presença de fraturas vertebrais em mulheres, e a condição de caidor crônico foi correlacionada com fraturas vertebrais em homens. / Purpose: To estimate the prevalence of radiographic vertebral fracture and investigate factors associated with this condition in Brazilian communitydwelling elderly. Methods: This cross sectional study included 769 elderly subjects 65 years old and over (462 women and 307 men) living in São Paulo, Brazil. Thoracic and lumbar spine radiographs were obtained and vertebral fractures were evaluated using Genant´s semi-quantitative method. Bone mineral density (BMD) was measured by DXA and bone biochemical markers were also evaluated. Female and male subjects were analyzed independently, and each gender was divided into 2 groups, based on whether vertebral fractures were present. Results: The prevalence of vertebral fracture was 16.7% (95% CI 13.3-20.1) in women and 21.2% (95% CI 16.6-25.7) in men. Logistic regression analyses using variables that were significant in the univariate analysis, in female group showed that age (OR=1.12, 95% CI 1.06-1.18; p<0.001) and femoral neck T-score (OR=0.61, 95% CI 0.46-0.88; p=0.006) were independently factors in predicting vertebral fracture. In the male group, logistic regression analyzes demonstrated that chronic faller condition (OR=2.54 95% CI 1.1-5.9; p=0.031) and femoral neck T-score (OR=0.72, 95% CI 0.53-0.96; p=0.025) were independent parameters in predicting vertebral fractures. Conclusions: Our results suggest that radiographic vertebral fractures are common in Brazilian community-dwelling elderly and that a low femoral neck T-score was an important risk factor for this condition in both males and females. Age was also significantly correlated with the presence of vertebral fractures in women, and chronic faller was correlated with vertebral fractures in men.
125

Efeito do metotrexato, do corticosteróide e do ácido zoledrônico na osseointegração de implantes de titânio em um modelo de tíbias de coelhos / Osseointegration of titanium implants in the rabbit tibia model: effect of methotrexate, corticosteroid and zoledronic acid

Janaina Santos Badin Carvas 10 October 2007 (has links)
No presente estudo avaliamos a influência do Metotrexato (MTX-3mg/kg/semana) e do Corticosteróide (CE- prednisona 1,05 mg/kg/semana), ministrados de forma isolada, associados entre si, ou associados ao Ácido Folínico (AF- 0,25 mg/kg/semana) e ao Ácido Zoledrônico (ZOL- 0,1mg/kg dose única) respectivamente, na osseointegração de implantes de titânio realizados 6 semanas após o início da administração das drogas, em coelhos NZW. Os animais (2,67 ± 0,67 Kg) foram tratados durante um total de 18 semanas com solução salina (CTL; n=6), MTX (n=6), CE (n=8), MTX-CE (n=6), MTX-AF (n=6) e CE-ZOL (n=6). Foram realizadas análises de densitometria mineral óssea (DMO) na tíbia e na coluna antes e após os tratamentos para avaliação da variação da DMO (Delta DMO). Os resultados revelaram perda de osso cortical nos grupos tratados com CE (Delta DMO tíbia: 0,018 ± 0,010 vs CTL: 0,040 ± 0,011 p= 0,001; Delta DMO coluna: 0,004± 0,011 vs CTL: 0,055 ± 0,009 p= 0,009). A adição de ZOL ao CE reverteu a perda de DMO (Delta DMO tíbia: 0,027 ± 0,003 p= 0,002 em relação ao CE; Delta DMO coluna: 0,043 ± 0,011 p= 0,02 em relação ao CE). O tratamento com MTX não promoveu alteração da DMO. As análises histomorfométricas das tíbias com e sem o implante, foram realizadas 12 semanas após a colocação dos implantes, e os resultados mostraram uma redução de espessura cortical e de tecido ósseo em função do tratamento com CE sendo que a adição de ZOL reverteu também esse parâmetro. Da mesma forma, o percentual de contato entre osso e o implante foi alterado pelo tratamento com CE (CE: 25,98% vs. CTL: 42,40%; p= 0,013) e o ZOL reverteu esse efeito (CE- ZOL: 38,95% vs. CE: 25,98%; p= 0,014). Em conjunto, nossos resultados mostraram que a terapia com MTX não alterou a osseointegração de implantes de titânio, enquanto que o CE promoveu uma diminuição de contato entre osso e implante que foi revertida pela administração de ZOL, comprovando a eficácia terapêutica dessa associação. / In this study we evaluated the influence of Methotrexate (MTX- 3mg/kg/week) and Corticosteroid (CE- prednisona 1, 05 mg/kg/week), alone and in association with Folinic Acid (FA- 0, 25 mg/kg/week) and Zoledronic Acid (ZOL-0,1mg/kg/week) respectively, on osseointegration of titanium dental implants performed 6 weeks after treatment started in adult male NZW rabbits. Six animals in each group and eight in CE, were treated with the drugs during 18 weeks with exception of ZOL, which was infused as a single dose, at the moment of surgery. Dual-energy X-ray absorptiometryies were performed before and after treatment to determine bone mineral density alterations (Delta BMD). After 12 weeks post-implant placement, the animals were sacrificed for histomorphometric analysis. The BMD was significantly reduced by treatment with CE (Delta tibia: 0.018±0.010 vs CTL: 0.040±0.011; Delta lumbar: 0.004±0.011 vs CTL: 0.055±0.009), with recovery of BMD after ZOL administration (Delta tibia: 0,027± 0,003 vs CE: 0,018±0,010; Delta lumbar: 0.043±0.011 vs CE: 0.004±0.011). The BMD was not altered by MTX treatment or MTX-FA. The histomorphometric analysis revealed cortical bone loss and reduction in bone tissue in tibia in animals treated with CE, and these parameters were reversed by ZOL. Similarly, the percentage of bone to implant contact was reduced in the group treated with CE (CE: 25.98% vs. CTL: 42.40%; p=0.013), and reverted by ZOL (CE+ZOL: 38.95% vs. CE: 25.98%; p=0.014).The MTX and MTX-FA treatments did not alter osseointegration of the implant (35.09% and 35.92% respectively). Together our results showed that therapy with MTX did not interfere on osseointegration of titanium implants, while the CE reduced the bone to implant contact. ZOL administration reversed this effect, showing the therapeutic importance of this association.
126

Avaliação da composição corporal e densidade mineral ósseo em mulheres com artrite reumatóide / Evaluation of body composition and body mineral density in women with rheumatoid arthritis

Raissa Gomes da Silva 21 March 2007 (has links)
INTRODUÇÃO: A diminuição da massa óssea e mudanças na composição corporal são comuns em pacientes com artrite reumatóide, particularmente nos usuários de glicocorticóide (GC). OBJETIVO: Analisar o comprometimento dos componentes da composição corporal e densidade mineral óssea (DMO) na artrite reumatóide (AR) e seus aspectos clínicos. MÉTODOS: 83 mulheres com AR realizaram densitometria óssea para análise de massa óssea total e regional e estudo da composição corporal (CC). Além disso, foram submetidas à realização laboratorial de provas inflamatórias, dosagem de fator reumatóide e aplicados questionários para avaliação da atividade da doença, classe funcional, atividade física, e inquérito alimentar. RESULTADOS: A prevalência de osteoporose nas pacientes menopausadas foi de 21,4%, 46,4% com osteopenia e 32,1% com valores normais e ocorreu de forma semelhante em coluna lombar e colo do fêmur. As mulheres na pré-menopausa apresentaram maiores valores nas médias de DMO. A idade teve efeito negativo nas medidas DMO e de CC enquanto que o índice de massa corpórea (IMC) mostrou efeito positivo nestas variáveis. A atividade física apresentou efeito positivo na DMO de fêmur total. A duração da AR teve efeito negativo na DMO de coluna lombar. O GC foi o determinante negativo na massa magra total e aumentou o percentual de gordura. CONCLUSÕES: O achado de valores reduzidos de DMO sugere que devam ser aplicadas medidas para a prevenção e tratamento de osteoporose. A doença (AR) também influenciou negativamente a DMO nestas pacientes e a utilização de GC modificou a CC, reduzindo a massa muscular e aumentando o percentual de gordura. A preservação da massa muscular é importante ao equilíbrio das pacientes, com conseqüente diminuição de quedas e futuras fraturas. / INTRODUCTION: The reduction of bone mass and changes in body compositions are usual in patients with rheumatoid arthritis specialty in users of glucocorticoid (GC). OBJECTIVE: To evaluate the bone mineral density (BMD) and body composition (BC) including its correlation to factors of rheumatoid arthritis (RA) and clinics concerns. METHODS: BMD and body composition (total and regional) were measured by densitometry in 83 patients with RA. Furthermore, it was performed laboratory exams (rheumatoid factor, inflammatory exams) and activity of disease, functional class, physical activity and alimentary data were colleted by specific questionnaires. RESULTS: The prevalence of osteoporosis in menopausal patients was 21,4%, 46,4% of osteopenia and 32,1% were normal and osteoporosis was similar in lumbar spine and femoral neck. Premenopausal women had the biggest values of BMD medias. Dose of GC was negative determinant of total lean mass and made positive effect in total fat percentual. Age made negative effect in BMD and body composition. BMI showed positive effect in all CC variables. The physical activity made positive effect in BMD in total femur. The RA duration had negative effect in BMD in lumbar spine. CONCLUSIONS: The finding of low BMD suggests a better approach to prevention and treatment. The disease (RA) also made a negative influence in BMD in these patients and the use of GC cause changes in body composition, with reduction in lean mass and improvement of total fat percentual. Recommendations to preservation of lean mass are important to reduction of falls and consequent diminution of fractures.
127

Factors Impacting Bone Mineral Density (BMD) Results of Individuals with Intellectual and Developmental Disabilities (IDD)

McNabb, Rhonda 01 May 2018 (has links)
Individuals with intellectual and developmental disabilities (IDD) are prone to certain diseases in their lifetime, such as osteoporosis. Absorption of calcium is essential to maintaining good bone health and preventing osteoporosis. This study examined primary care providers’ (PCPs) choice of calcium supplementation, as well as type of calcium supplementation, and the relationship between variables in the IDD population. Ten PCPs were asked to complete a 14-question web-based survey, with five surveys completed. Calcium citrate was the preferred supplement among respondents at 50%. Retrospective data was collected from patient records and included type of calcium supplement prescribed, bone density test results, and other variable factors. The type of calcium supplement prescribed did not affect bone density results in subjects with IDD. There was a weak significance between calcium supplement type and gender and vitamin D. It is of modest benefit to include vitamin D with calcium supplementation to enhance calcium absorption.
128

Relationship of Training Volume to Bone Mineral Density In NCAA Division I Cross‐Country Runners

Kavanaugh, Ashley A., South, Mark A., Painter, K., Stone, Michael E., Byrne, M. M., Hamdy, Ronald C., Haff, G. G., Stone, Michael H., Ramsey, Michael W. 01 December 2008 (has links)
No description available.
129

Relationship of Training Volume to Bone Mineral Density in NCAA Division in Cross-Country Runners

Kavanaugh, Ashley A., Ramsey, Michael W., South, Mark, Painter, Keith B., Hamdy, Ronald C., Haff, G. Gregory, Stone, Margaret E., Byrne, M. M., Stone, Michael H. 01 June 2009 (has links)
No description available.
130

Identifying Genes Influencing Bone Mineral Density

Vaughan, Tanya, n/a January 2004 (has links)
Bone mineral density (BMD) is a reflection of the action of osteoblasts compared to osteoclasts. An imbalance in the activity of osteoblasts or osteoclasts, results in bone disease such as osteoporosis caused by overactive osteoclasts. BMD is influenced by genetic and environmental factors as demonstrated through twin studies, association studies and linkage analysis (Ralston, 1999). Several polymorphisms involved in the determination of BMD have been identified, with Vitamin D receptor and Collagen Type 1 showing reproducible associations. To identify genes influencing BMD two distinct strategies have been employed: 1) To determine if DNA polymorphism within the runt related transcription factor (RUNX2) gene is a determinant of BMD and fracture in women. 2) The identification of RANKL target genes in osteoclastogenesis. RUNX2 is a runt domain transcription factor (Werner et al., 1999) essential for osteoblast differentiation (Lee et al., 1997). RUNX2 gene knock-out mice have no osteoblasts due to a failure in osteoblast differentiation and consequently unmineralised skeletons, (Komori et al., 1997; Otto et al., 1997). In humans, mutations in RUNX2 cause cleidocranial dysplasia (CCD), a disorder characterised by hypoplasia or aplasia of the clavicles, short stature, supernumerary teeth, patent fontanelles and other changes in skeletal patterning and growth (Mundlos et al., 1997). RUNX2 contains a poly-glutamine poly-alanine (polyQ/polyA) repeat where mutations causing cleidocranial dysplasia have been observed. BMD has not been routinely examined in CCD, two studies have identified CCD patients with lower BMD with one fracture case identified (Quack et al., 1999; Bergwitz et al., 2001). The central role of RUNX2 in determining osteoblast differentiation makes RUNX2 a prime candidate gene for regulating adult bone density. To determine if polymorphism was present in the polyQ/polyA tract the repeat was amplified within the upper and lower deciles of femoral neck (FN) BMD in the Geelong Osteoporosis study (GOS). The upper and lower deciles of FN BMD acted as a surrogate for genotyping the entire cohort. This study identified two common variants within the polyA repeat: an 18 base pair deletion (11Ala) and a synonymous alanine codon polymorphism with alleles, GCA and GCG (noted as A and G alleles, respectively). The 11Ala and SNP polymorphism are found on codon 64 and 66 respectively (RUNX2 MRIPV variant). A allele frequencies were significantly different in a comparison of the upper and lower deciles of FN BMD (p=0.019). In 495 randomly selected women of the Geelong Osteoporosis Study (GOS), the A allele was associated with higher BMD at all sites tested. The association was maximal at the ultra-distal radius (p=0.001). In a separate fracture study, the A allele was significantly protective against Colles' fracture in elderly women but not spine and hip fracture. The 11Ala polymorphism was not related to BMD in GOS. To further decipher the role of the RUNX2 A allele we genotyped 992 women from a Scottish cohort. The alleles of RUNX2 within the glutamine/alanine repeat were determined by MspA1I restriction digest. To examine the possible influence on estrogen related therapies or estrogen status on the potential genetic effect conferred by RUNX2, we divided the cohort by menopausal and hormone replacement therapy status. Within postmenopausal Scottish women the RUNX2 A allele was associated with significantly higher FN BMD (p=0.028, n=312) but not lumbar spine (LS) BMD. The A allele was associated with higher FN BMD (p=0.035) within a postmenopausal subgroup of the population (n=312). To investigate the effect of weight on the RUNX2 alleles the Scottish cohort was segregated into thin/normal (BMI ≥ 25 kg/m2) and overweight /obese (BMI > 25 kg/m2). RUNX2 A allele showed a stronger effect on FN BMD in postmenopausal women above the median BMI. The 11Ala RUNX2 deletion allele was significantly associated with decreased LS BMD (p=0.018) within overweight/obese women (n=546). The 11Ala allele was significantly associated with increased levels of pyridinoline (p=0.014) and deoxypyridinoline (p=0.038) in the HRT treated subgroup of the population (n=492). Glutamine variants and an alanine insertion were identified within the group. These data suggest that the RUNX2 11Ala and A alleles exert differing affects on BMD showing preference for different skeletal sites in a weight dependent manner. We genotyped 78 individuals from an osteoarthritic population to elucidate the role of the RUNX2 alleles on markers of bone turnover and inflammation. The RUNX2 11Ala allele was significantly associated with decreased osteocalcin (OC) serum levels (p = 0.01). The RUNX2 A allele was significantly related to reduced tumor necrosis factor alpha (TNF-alpha) serum levels (p = 0.004). RUNX2 is known to bind to the OC promoter. An OC promoter polymorphism is found 7bp upstream from a putative RUNX2 binding site. We hypothesized that OC polymorphism may effect the RUNX2 transactivation of the OC gene and thus affect OC serum levels. OC promoter polymorphism was not related to OC serum levels (n=78). These data present a novel link between RUNX2 alleles and OC and TNF serum levels, providing putative mechanisms of action for the RUNX2 alleles. Further studies in larger populations are required to confirm these findings. Ten individuals within the GOS and the Scottish cohort were found to carry rare mutations of the polyQ/polyA repeat. All polyQ variants had a normal polyA repeat (17 amino acids) and were heterozygous for a normal 23Q/17A allele. Variants observed were 15, 16, 24 and 30Q. One individual was observed with an extended polyA repeat (24A). Patient records indicated otherwise unremarkable clinical history except for fracture in 4/10 individuals from GOS (hip and spine). BMD data from the LS and the FN were expressed as T-scores, a measure that relates BMD in terms of standard deviations below the young normal value. In addition, BMD data were also expressed as Z-scores around the age-mean. Under the null hypothesis, where RUNX2 Q repeat variation has no effect on BMD, Z scores would be expected to be distributed around a mean of zero. However, when all variants were pooled the BMD was significantly lower than expected. This effect persisted when deletion variants were considered alone. The effect was stronger on FN BMD (p=0.001) rather than LS BMD (p=0.096), reflecting either difference in precision of BMD measurements at these sites or perhaps a differential genetic effect on different skeletal sites. These data suggest that polyQ and polyA variants are associated with significantly lower BMD, and may be an important determinant for fracture. Glutamine variants exist at high frequency (~0.7%): this rate of mutation could be important when considering large populations at risk of age related osteoporosis. Considering that these subjects are heterozygous for a normal allele, it suggests that a more severe phenotype might be expected in rare subjects homozygous for glutamine repeat variants. In summary, this study investigated the role of novel polymorphisms and rare variants of the RUNX2 gene in influencing BMD, fracture and markers of bone turnover. Two common polymorphisms were identified within the polyA repeat: an 18 base pair deletion and a synonymous alanine codon polymorphism with alleles, A and G. The A allele was associated with increased BMD and was protective against a common form of osteoporotic fracture within a Geelong population. To verify these findings the RUNX2 alleles were genotyped in 992 women from a Scottish cohort. The magnitude and the direction of the effect of the A allele was maintained in the Scottish cohort. Interestingly, the A allele was shown to exert a menopause specific effect, with postmenopausal women showing the strongest effect. On re-analysis of the GOS data the post-menopausal women were found to drive the significance identified in the cohort. The magnitude of the effect of the A allele on BMD was greater in overweight/obese postmenopausal women indicating a gene-weight interaction for RUNX2. The RUNX2 11Ala allele showed a significant relationship with decreased LS BMD in overweight/obese Scottish women. The 11Ala allele was also associated with higher levels of urinary PYD and DPD in women treated with HRT, indicating higher levels of bone turnover in carriers of the 11Ala allele. In contrast to the Scottish cohort, no significant association with heterozygous carriers of 11Ala was observed in GOS, although a significant association was detected for homozygous carriers and LS BMAD. The 11 Ala RUNX2 allele was significantly associated with decreased serum osteocalcin levels and the A allele was significantly associated with TNF in OA patients. Glutamine variants and an alanine insertion were identified within Geelong and Scottish cohorts, which showed low Z and T scores suggesting that RUNX2 variants may be related to genetic effects on BMD and osteoporosis. Polymorphism of the polyQ/polyA region of RUNX2 were identified within this study were shown to associate with significant differences in BMD. The A allele showed a significant association with increased BMD in postmenopausal women from a Geelong and Scottish cohort, with a decreased frequency of the A allele observed in Colles' fracture patients from Geelong. The 11Ala deletion allele was significantly associated with decreased LS BMD and increases in markers of bone turnover in the Scottish cohort. A significant decrease in OC serum levels was observed in OA patients suggesting a direct effect of the allele on the transactivation of the RUNX2 gene. Rare variants of RUNX2 were identified which showed low BMD. These studies have provided insight into the role of RUNX2 in influencing BMD, further studies are required to verify the role of the A allele on BMD and fracture, the role of the rare variants and to identify the precise mechanisms behind the observed changes in BMD. - 2) The identification of RANKL target genes in osteoclastogenesis. Osteoclastogenesis is regulated in vivo by the action of osteoblast/stromal cells that express membrane bound, receptor activator of NF-kB ligand (RANKL). Monocytes treated in vitro with a soluble form of RANKL and macrophage colony stimulating factor (M-CSF) differentiate to osteoclasts, whereas monocytes treated with M-CSF alone differentiate to macrophage-like cells. The gene expression profile of human osteoclasts has not been extensively explored. Genes highly expressed by rabbit osteoclasts were identified through random sequencing of an osteoclast cDNA library (Sakai et al., 1995). Differential gene expression of mouse osteoclastogenesis was elucidated by array analysis (Cappellen et al., 2002). To identify genes important for human osteoclastogenesis, total RNA was isolated from monocytes treated for three weeks with either M-CSF alone or with RANKL and M-CSF. RANKL treatment for 3 weeks and 12 hours was investigated in this study, to complement previous data. Differential display was performed on RNA (12 hour treatment with RANKL) and differential gene expression profiles examined. The differential display products were pooled to generate a probe for screening a gene array system derived from a human osteoclast cDNA library. cDNA (3 week treatment with RANKL) hybridisation experiments against the array revealed additional regulated genes. Gene clones that showed significant regulation in M-CSF and RANKL treated cells compared M-CSF treated cells represent genes that are targets for RANKL-specific regulation. Osteopontin, creatine kinase and various mitochondrial genes were up regulated by the treatment of RANKL. Changes in gene expression observed in the array data were confirmed with real-time PCR using mRNA derived from in vitro induced osteoclasts. Cathepsin K gene expression was more than 300 fold greater in osteoclasts compared to macrophage-like cells after one week treatment with RANKL and M-CSF. Cystatin C expression showed a six-fold induction at two weeks of RANKL and M-CSF treatment and cystatin B showed a steady increase in expression. Some of these regulated genes may provide useful targets for influencing BMD.

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