RESUMO
The Risk-stratified Osteoporosis Strategy Evaluation (ROSE) study investigated the effectiveness of a two-step screening program for osteoporosis in women. We found no overall reduction in fractures from systematic screening compared to the current case-finding strategy. The group of moderate- to high-risk women, who accepted the invitation to DXA, seemed to benefit from the program. INTRODUCTION: The purpose of the ROSE study was to investigate the effectiveness of a two-step population-based osteoporosis screening program using the Fracture Risk Assessment Tool (FRAX) derived from a self-administered questionnaire to select women for DXA scan. After the scanning, standard osteoporosis management according to Danish national guidelines was followed. METHODS: Participants were randomized to either screening or control group, and randomization was stratified according to age and area of residence. Inclusion took place from February 2010 to November 2011. Participants received a self-administered questionnaire, and women in the screening group with a FRAX score ≥ 15% (major osteoporotic fractures) were invited to a DXA scan. Primary outcome was incident clinical fractures. Intention-to-treat analysis and two per-protocol analyses were performed. RESULTS: A total of 3416 fractures were observed during a median follow-up of 5 years. No significant differences were found in the intention-to-treat analyses with 34,229 women included aged 65-80 years. The per-protocol analyses showed a risk reduction in the group that underwent DXA scanning compared to women in the control group with a FRAX ≥ 15%, in regard to major osteoporotic fractures, hip fractures, and all fractures. The risk reduction was most pronounced for hip fractures (adjusted SHR 0.741, p = 0.007). CONCLUSIONS: Compared to an office-based case-finding strategy, the two-step systematic screening strategy had no overall effect on fracture incidence. The two-step strategy seemed, however, to be beneficial in the group of women who were identified by FRAX as moderate- or high-risk patients and complied with DXA.
Assuntos
Programas de Rastreamento/organização & administração , Osteoporose Pós-Menopausa/diagnóstico por imagem , Fraturas por Osteoporose/prevenção & controle , Absorciometria de Fóton/métodos , Idoso , Idoso de 80 Anos ou mais , Dinamarca/epidemiologia , Feminino , Seguimentos , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Fraturas do Quadril/prevenção & controle , Humanos , Incidência , Programas de Rastreamento/métodos , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/epidemiologia , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Medição de Risco/métodos , Fatores de Risco , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
Population-based screening for osteoporosis is still controversial and has not been implemented. Non-participation in systematic screening was evaluated in 34,229 women age 65-81 years. Although participation rate was high, non-participation was associated with comorbidity, aging other risk factors for fractures, and markers of low social status, e.g., low income, pension, and living alone. A range of strategies is needed to increase participation, including development of targeted information and further research to better understand the barriers and enablers in screening for osteoporosis. INTRODUCTION: Participation is crucial to the success of a screening program. The objective of this study was to analyze non-participation in Risk-stratified Osteoporosis Strategy Evaluation, a two-step population-based screening program for osteoporosis. METHODS: Thirty-four thousand two hundred twenty-nine women aged 65 to 81 years were randomly selected from the background population and randomized to either a screening group (intervention) or a control group. All women received a self-administered questionnaire designed to allow calculation of future risk of fracture based on FRAX. In the intervention group, women with an estimated high risk of future fracture were invited to DXA scanning. Information on individual socioeconomic status and comorbidity was obtained from national registers. RESULTS: A completed questionnaire was returned by 20,905 (61%) women. Non-completion was associated with older age, living alone, lower education, lower income, and higher comorbidity. In the intervention group, ticking "not interested in DXA" in the questionnaire was associated with older age, living alone, and low self-perceived fracture risk. Women with previous fracture or history of parental hip fracture were more likely to accept screening by DXA. Dropping out when offered DXA, was associated with older age, current smoking, higher alcohol consumption, and physical impairment. CONCLUSIONS: Barriers to population-based screening for osteoporosis appear to be both psychosocial and physical in nature. Women who decline are older, have lower self-perceived fracture risk, and more often live alone compared to women who accept the program. Dropping out after primary acceptance is associated not only with aging and physical impairment but also with current smoking and alcohol consumption. Measures to increase program participation could include targeted information and reducing physical barriers for attending screening procedures.
Assuntos
Programas de Rastreamento/psicologia , Osteoporose Pós-Menopausa/diagnóstico , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Absorciometria de Fóton/métodos , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Dinamarca , Feminino , Humanos , Programas de Rastreamento/métodos , Osteoporose Pós-Menopausa/psicologia , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/prevenção & controle , Fraturas por Osteoporose/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Pacientes Desistentes do Tratamento/psicologia , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Participação do Paciente , Medição de Risco/métodos , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
SUMMARY: This Danish cross-sectional study (n=20,905) showed that women aged 65-81 years generally underestimated fracture risk compared to absolute risk estimated by the FRAX® algorithm. Significant association was found between risk factors (e.g., previous fracture, parental hip fracture, and self-rated heath) and self-perceived fracture risk. Although women recognized the importance of some fracture risk factors, a number of significant risk factors appeared to be less well known. INTRODUCTION: The aim of this study is to investigate women's self-perceived fracture risk and potential factors associated with this and to compare self-perceived risk with absolute fracture risk estimated by FRAX® in women aged 65-80 years. METHODS: Data from 20,905 questionnaires from the ROSE study were analyzed. The questionnaire included 25 items on osteoporosis, risk factors for fractures, and self-perceived risk of fractures and enabled calculation of absolute fracture risk by FRAX®. Data were analyzed using bivariate tests and regression models. RESULTS: Women generally underestimated their fracture risk compared to absolute risk estimated by FRAX®. Women with risk factors for facture estimated their fracture risk significantly higher than their peers. No correlation between self-perceived risk and absolute risk was found. The ordered logistic regression model showed a significant association between high self-perceived fracture risk and previous fragility fracture, parental hip fracture, falls, self-rated heath, conditions related to secondary osteoporosis, and inability to do housework. CONCLUSIONS: These women aged 65-81 years underestimated their risk of fracture. However, they did seem to have an understanding of the importance of some risk factors such as previous fractures, parental hip fracture and falls. Risk communication is a key element in fracture prevention and should have greater focus on less well-known risk factors. Furthermore, it is important to acknowledge that risk perception is not based solely on potential risk factors but is also affected by experiences from everyday life to personal history.
Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Fraturas por Osteoporose/psicologia , Autoimagem , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Estudos Transversais , Dinamarca , Feminino , Humanos , Osteoporose Pós-Menopausa/complicações , Fraturas por Osteoporose/etiologia , Medição de Risco/métodos , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
UNLABELLED: Quantitative ultrasound (QUS) measurement variables vary between European countries in a different way to hip bone mineral density. Standardization of data can be achieved through statistical approaches to reduce any between-center differences in QUS measurement variables. However, further validation of this method is required before it can be widely applied. INTRODUCTION: European between-center differences in hip bone mineral density (BMD) have been shown to exist; however, little is known about the geographical heterogeneity of QUS measurement variables. We aimed to examine the differences in QUS variables between three different European countries. METHODS: Five calcaneal and phalangeal QUS devices in Sheffield, Aberdeen (UK), Kiel and Berlin (Germany), and three devices in Paris (France) were used to measure QUS variables in younger (n = 463, 20-39 years old) and older (n = 2,399, 55-79 years old) women participating in the European multicenter Osteoporosis and Ultrasound (OPUS) study. Broadband ultrasound attenuation, speed of sound, stiffness index, amplitude-dependent speed of sound, bone transmission time, and ultrasonic bone profiler index data were collected. Between-center differences were examined using ANOVA followed by post hoc Fisher's least significant difference tests, and ANCOVA with linear contrasts. p < 0.05 indicated statistical significance. RESULTS: Between-center differences in nonstandardized QUS measurement variables existed for younger (p = 0.0023 to p < 0.0001) and older women (p < 0.001). Anthropometric characteristics exerted a significant influence on nonstandardized data (p = 0.045 to p < 0.001). However, following statistical standardization, based on height and weight or based on measurements made in young people, geographical heterogeneity in QUS measurement variables was no longer apparent. CONCLUSIONS: QUS measurement variables vary between European countries in a different way to those for hip BMD. Standardization of data can be achieved through statistical approaches to reduce any between-center differences in QUS measurement variables. However, further validation of this method is required before it can be widely applied.
Assuntos
Densidade Óssea/fisiologia , Calcâneo/diagnóstico por imagem , Falanges dos Dedos da Mão/diagnóstico por imagem , Osteoporose/diagnóstico por imagem , Absorciometria de Fóton/normas , Adulto , Distribuição por Idade , Idoso , Antropometria , Calcâneo/fisiologia , Europa (Continente)/epidemiologia , Feminino , Colo do Fêmur/fisiologia , Falanges dos Dedos da Mão/fisiologia , Articulação do Quadril/fisiologia , Humanos , Pessoa de Meia-Idade , Osteoporose/epidemiologia , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/epidemiologia , Valores de Referência , Reprodutibilidade dos Testes , Ultrassonografia , Adulto JovemRESUMO
UNLABELLED: We observed higher proximal femur bone mineral density (BMD) in European women compared to average values derived from US Caucasian women in the National Health and Nutrition Examination Survey (NHANES) study. Across European centres, Parisian women had lower proximal femur BMD compared to women from Kiel or Sheffield. INTRODUCTION: Proximal femur BMD of US adults (NHANES III) may not accurately reflect that of European women. We examined the heterogeneity of BMD across European and US Caucasian women and across different European populations. METHODS: Proximal femur BMD was measured in women ages 20-39 years (n=258) and 55-79 years (n=1,426) from three European centres. Cross-calibrated BMD for total hip, femoral neck, trochanter and intertrochanter were examined. International variation in BMD was assessed by comparing means and SDs in the European data with those from the US NHANES III study. European populations were stratified into 5-year age bands to establish individual centre reference intervals. Between-centre differences were assessed using ANOVA and post hoc Fisher's least significant difference tests. RESULTS: European women had higher BMD than US women: The differences were 7.1% to 14.2% (p<0.001) and 0% to 3.9% (p<0.05) in the older and younger women, respectively. Standard deviations for BMD at the different sites were comparable to those for US women. Among older, but not younger European women, proximal femur BMD was significantly lower in French women (Paris) than in women from Germany (Kiel) or the UK (Sheffield) (difference=5.0% to 9.6%, p<0.05). CONCLUSIONS: International variation in hip BMD does exist, with international and between-centre differences being less evident at the femoral neck.
Assuntos
Densidade Óssea/fisiologia , Fêmur/diagnóstico por imagem , Quadril/diagnóstico por imagem , Absorciometria de Fóton , Adulto , Idoso , Europa (Continente)/etnologia , Feminino , Colo do Fêmur/diagnóstico por imagem , Inquéritos Epidemiológicos , Humanos , Pessoa de Meia-Idade , Valores de Referência , Estados Unidos/etnologia , População Branca/etnologia , Adulto JovemRESUMO
SUMMARY: A quantitative ultrasound (QUS) device for measurements at the proximal femur was developed and tested in vivo (Femur Ultrasound Scanner, FemUS). Hip fracture discrimination was as good as for DXA, and a high correlation with hip BMD was achieved. Our results show promise for enhanced QUS-based assessment of osteoporosis. INTRODUCTION: Dual X-ray absorptiometry (DXA) at the femur is the best predictor of hip fractures, better than DXA measurements at other sites. Calcaneal quantitative ultrasound (QUS) can be used to estimate the general osteoporotic fracture risk, but no femoral QUS measurement has been introduced yet. We developed a QUS scanner for measurements at the femur (Femur Ultrasound Scanner, FemUS) and tested its in vivo performance. METHODS: Using the FemUS device, we obtained femoral QUS and DXA on 32 women with recent hip fractures and 30 controls. Fracture discrimination and the correlation with femur bone mineral density (BMD) were assessed. RESULTS: Hip fracture discrimination using the FemUS device was at least as good as with hip DXA and calcaneal QUS. Significant correlations with total hip bone mineral density were found with a correlation coefficient R (2) up to 0.72 and a residual error of about one half of a T-score in BMD. CONCLUSIONS: QUS measurements at the proximal femur are feasible and show a good performance for hip fracture discrimination. Given the promising results, this laboratory prototype should be reengineered to a clinical applicable instrument. Our results show promise for further enhancement of QUS-based assessment of osteoporosis.
Assuntos
Densidade Óssea/fisiologia , Fêmur/diagnóstico por imagem , Fraturas do Quadril/diagnóstico por imagem , Fraturas por Osteoporose/diagnóstico por imagem , Absorciometria de Fóton/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Estudos de Viabilidade , Feminino , Fêmur/fisiopatologia , Fraturas do Quadril/etiologia , Fraturas do Quadril/fisiopatologia , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Osteoporose Pós-Menopausa/diagnóstico por imagem , Osteoporose Pós-Menopausa/fisiopatologia , Fraturas por Osteoporose/fisiopatologia , UltrassonografiaRESUMO
Quantitative ultrasound (QUS) measurements at peripheral sites can be used to estimate osteoporotic fracture risk. However, measurements at these sites are less suitable to predict bone mineral density (BMD) or fracture risk at the central skeleton. We investigated whether direct QUS measurements at the femur would allow to estimate dual X-ray absorptiometry (DXA) BMD of the total proximal femur with errors comparable to established DXA accuracy errors. Two independent sets of femora were measured in Kiel (6 f, 4 m, age: 55-90) and Paris (19 f, 20 m age: 45-95) using different benchtop systems in the two laboratories. The femora were scanned in transverse transmission mode using focused US transducers of 500 kHz center frequency. The QUS values were averaged over a region similar to the total hip region of dual X-ray absorptiometry (DXA) measurements. BMD was measured using DXA. SOS and BMD correlated significantly (p<0.0001) in both data sets (R2=0.81-0.93). Correlations between BUA and BMD were also significant at p<0.001, but correlation coefficients were lower (R2=0.61-0.75). Residual errors for the estimation of BMD were 8%-10% for SOS as predictor, and 14%-16% for BUA as predictor. The residual error of 8 to 10% for the estimation of BMD from SOS is comparable to variabilities among different DXA femur subregions and accuracy errors of femoral DXA measurements caused by the impact of soft tissue. It is substantially smaller than the errors of 13% for the estimation of total femur BMD from spine BMD, 14% for the estimation of total femur BMD from calcaneus SOS or 16% for the estimation of ash weight from DXA. The results of the study show that SOS is able to predict total BMD with adequate accuracy. If femoral BMD could be obtained in vivo with comparable accuracy, femoral QUS would be suited for the assessment of bone status at one of the main osteoporotic fracture sites.
Assuntos
Densidade Óssea , Fêmur/diagnóstico por imagem , Ultrassonografia/normas , Absorciometria de Fóton , Cadáver , Feminino , Humanos , UltrassomRESUMO
The Göttingen minipig is one of the few large animal models that show glucocorticoid (GC)-induced bone loss. We investigated whether GC-induced loss of bone mineral density (BMD) and bone strength in minipigs can be recovered by treatment with the bisphosphonate ibandronate (IBN). 40 primiparous sows were allocated to 4 groups when they were 30 months old: GC treatment for 8 months (GC8), for 15 months (GC15), GC treatment for 15 months plus IBN treatment for months 8-15 (GC&IBN), and a control group without GC treatment. Prednisolone was given at a daily oral dose of 1 mg/kg body weight for 8 weeks and thereafter 0.5 mg/kg body weight. IBN was administered intramuscularly and intermittently with an integral dose of 2.0 mg/kg body weight. BMD of the lumbar spine (L1-3) was assessed in vivo by Quantitative Computed Tomography (QCT) at months 0, 8, and 15. Blood and urine samples were obtained every 2-3 months. After sacrificing the animals lumbar vertebrae L4 were tested mechanically (Young's modulus and ultimate stress). Histomorphometry was performed on L2 and mineral content determined in ashed specimens of T12 and L4. In the GC&IBN group, the GC associated losses in BMD of -10.5%+/-1.9% (mean+/-standard error of the mean, p<0.001) during the first 8 months were more than recovered during the following 7 months of IBN treatment (+14.8%+/-1.2%, p<0.0001). This increase was significantly larger (p<0.0001) than the insignificant +2.1%+/-1.2% change in group GC15. At month 15, the difference between groups GC&IBN and GC15 was 22% (p<0.01) for BMD, 48% (p<0.05) for Young's modulus, and 31% (p<0.14) for ultimate stress; bone-specific alkaline phosphatase showed trends to lower values (p<0.2) while deoxypyridinoline was comparable. This minipig study demonstrates that GC-induced impairment of bone strength can be effectively and consistently treated by IBN. GC&IBN associated alterations in BMD and bone turnover markers can be monitored in vivo using QCT of the spine and by biochemical analyses, reflecting the changes in bone strength.
Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Difosfonatos/uso terapêutico , Glucocorticoides/efeitos adversos , Osteoporose/induzido quimicamente , Osteoporose/prevenção & controle , Absorciometria de Fóton , Fosfatase Alcalina/sangue , Fosfatase Alcalina/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Feminino , Ácido Ibandrônico , Vértebras Lombares/efeitos dos fármacos , Suínos , Porco MiniaturaRESUMO
Quantitative ultrasound (QUS) measurements of trabecular bone are a useful tool for the assessment of osteoporotic fracture risk. However, cortical bone properties (e.g. porosity) have an impact on bone strength as well and thus current research is focused on QUS assessment of cortical bone properties. Simulation studies of ultrasound propagation through cortical bone indicate that anisotropy, calculated from the ratio of the velocities in axial and tangential directions, is correlated with porosity. However, this relationship is affected by error sources, specifically bone surface curvature and variability of probe positioning. With the aim of in vivo estimation of cortical porosity a new ultrasound device was developed, which sequentially measures velocities in 3 different directions (axial=0° and ±37.5°) using the axial transmission method. Measurements on planar porosity phantoms (0-25%) were performed to confirm the results of the afore mentioned simulation studies. Additionally, measurements on cylindrical phantoms without pores (min. radius=34mm for strongest curvature) were performed to estimate the influence of surface curvature on velocity measurements (the tibia bone surface is fairly flat but may show surface curvature in some patients). The velocities in the axial and ±37.5° directions were used to calculate an anisotropy index. The velocities measured on the porosity phantoms showed a decrease by -6.3±0.2m/s and -10.1±0.2m/s per percent increase in porosity in axial and ±37.5° directions, respectively. Surface curvature had an effect on the velocities measured in ±37.5° directions which could be minimized by a correction algorithm resulting in an error of 5m/s. The anisotropy index could be used to estimate porosity with an accuracy error of 1.5%. These results indicate that an estimation of porosity using velocity measurements in different directions might be feasible, even in bones with curved surface. These results obtained on phantom material indicate that the approach tested may be suited for porosity measurements on human tibia bone.
Assuntos
Tíbia/diagnóstico por imagem , Ultrassonografia/métodos , Anisotropia , Densidade Óssea , Desenho de Equipamento , Humanos , Imagens de Fantasmas , Porosidade , Ultrassonografia/instrumentaçãoRESUMO
Quantitative parametric imaging approaches provide new perspectives for radiological imaging. These include quantitative 2D, 3D, and 4D visualization options along with the parametric depiction of biological tissue properties and tissue function. This allows the interpretation of radiological data from a biochemical, biomechanical, or physiological perspective. Quantification permits the detection of small changes that are not yet visually apparent, thus allowing application in early disease diagnosis and monitoring therapy with enhanced sensitivity. This review outlines the potential of quantitative parametric imaging methods and demonstrates this on the basis of a few exemplary applications. One field of particular interest, the use of these methods for investigational new drug application studies, is presented. Assessment criteria for judging the quality of quantitative imaging approaches are discussed in the context of the potential and the limitations of these methods. While quantitative parametric imaging methods do not replace but rather supplement established visual interpretation methods in radiology, they do open up new perspectives for diagnosis and prognosis and in particular for monitoring disease progression and therapy.
Assuntos
Diagnóstico por Imagem/métodos , Processamento de Imagem Assistida por Computador , Algoritmos , Meios de Contraste , Interpretação Estatística de Dados , Erros de Diagnóstico , Diagnóstico por Imagem/normas , Progressão da Doença , Análise de Elementos Finitos , Seguimentos , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Neoplasias/irrigação sanguínea , Neoplasias/diagnóstico , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Osteoartrite/diagnóstico , Osteoporose/diagnóstico , Osteoporose/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Guias de Prática Clínica como Assunto , Prognóstico , Valores de Referência , Sensibilidade e Especificidade , Fatores de Tempo , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Carga TumoralRESUMO
Type 2 diabetes mellitus increases skeletal fragility; however, the contributing mechanisms and the efficacy of bone-forming agents are unclear. We studied diabetes and parathyroid hormone (PTH) treatment effects on cortical porosity (Ct.Po), non-enzymatic glycation (NEG) and bone mechanics in Zucker diabetic fatty (ZDF) rats. Eleven-week old ZDF diabetic (DB) and non-diabetic (ND) rats were given 75µg/kg PTH (1-84) or vehicle 5days per week over 12weeks. The right femora and L4 vertebrae were excised, micro-CT scanned, and tested in 3-point bending and uniaxial compression, respectively. NEG of the samples was determined using fluorescence. Diabetes increased Ct.Po (vertebra (vert): +40.6%, femur (fem): +15.5% vs. ND group, p<0.05) but had no effect on NEG. PTH therapy reduced vertebral NEG in the ND animals only (-73% vs untreated group, p<0.05), and increased femoral NEG in the DB vs. ND groups (+63%, p<0.05). PTH therapy had no effect on Ct.Po. Diabetes negatively affected bone tissue mechanics where reductions in vertebral maximum strain (-22%) and toughness (-42%) were observed in the DB vs. ND group (p<0.05). PTH improved maximum strain in the vertebra of the ND animals (+21%, p<0.05) but did not have an effect in the DB group. PTH increased femoral maximum strain (+21%) and toughness (+28%) in ND and decreased femoral maximum stress (-13%) and toughness (-27%) in the DB animals (treated vs. untreated, p<0.05). Ct.Po correlated negatively with maximum stress (fem: R=-0.35, p<0.05, vert: R=-0.57, p<0.01), maximum strain (fem: R=-0.35, p<0.05, vert: R=-0.43, p<0.05) and toughness (fem: R=-0.34, p<0.05, vert: R=-0.55, p<0.01), and NEG correlated negatively with toughness at the femur (R=-0.34, p<0.05) and maximum strain at the vertebra (R=-0.49, p<0.05). Diabetes increased cortical porosity and reduced bone mechanics, which were not improved with PTH treatment. PTH therapy alone may worsen diabetic bone mechanics through formation of new bone with high AGEs cross-linking. Optimal treatment regimens must address both improvements of bone mass and glycemic control in order to successfully reduce diabetic bone fragility. This article is part of a Special Issue entitled "Bone and diabetes".
Assuntos
Densidade Óssea/efeitos dos fármacos , Densidade Óssea/fisiologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Hormônio Paratireóideo/uso terapêutico , Animais , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação/efeitos dos fármacos , Masculino , Hormônio Paratireóideo/farmacologia , Porosidade/efeitos dos fármacos , Ratos , Ratos Zucker , Resultado do TratamentoRESUMO
Quantitative ultrasound has been recognized as a useful tool for fracture risk prediction. Current measurement techniques are limited to peripheral skeletal sites. Our objective was to demonstrate the in vitro feasibility of ultrasonic velocity measurements on human proximal femur and to investigate the relationship between velocity and bone mineral density (BMD). Sound velocity images were computed from 2-D scans performed on 38 excised human femurs in transmission at 0.5 MHz. Different regions-of-interest were investigated. Dual x-ray absorptiometry scans have been achieved for BMD measurements in site-matched regions. Our study demonstrates the feasibility of ultrasonic velocity measurements at the hip with reasonable precision (coefficient of variation of 0.3%). The best prediction of BMD was reached in the intertrochanter region (r(2) = 0.91, p < 10(-4)), with a residual error of 0.06 g/cm(2) (10%). Because BMD measured at the femur is the best predictor of hip fracture risk, the highly significant correlation and small residual error found in this study suggest that speed of sound measurement at the femur might be a good candidate for hip fracture risk prediction.
Assuntos
Densidade Óssea , Fêmur/diagnóstico por imagem , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Fêmur/fisiologia , Fraturas do Quadril/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/complicações , Osteoporose/diagnóstico por imagem , Reprodutibilidade dos Testes , Medição de Risco/métodos , UltrassonografiaRESUMO
There is a growing interest in the use of quantitative ultrasound (QUS) measurements as an alternative to current radiation-based bone densitometry techniques for the noninvasive assessment of fracture risk. While most of the commercialized ultrasound devices measure only single predefined peripheral skeletal sites, the Omnisense prototype (Sunlight Ltd., Israel) can be used on multiple bones, including the spinous processes. In this study, we examined the ability of speed of sound measured at the calcaneus, distal third and ultradistal radius, proximal third phalanx, metacarpal, capitate, patella, and the posterior process of the thoracic spine to differentiate subjects with hip fractures from normal controls. Seventy-nine postmenopausal Caucasian Israeli women who had sustained an atraumatic fracture of the proximal femur within the last 6 months were recruited from the local population (mean age 80 +/- 8.9 years). As controls, 295 postmenopausal Caucasian Israeli women without osteoporotic fractures were also included (mean age 70 +/- 8.7 years). Discrimination of hip fractures with QUS at all ultrasound sites was highly statistically significant (p < 0.01) (odds ratios [ORs] = 1.4-3.0; area under the ROC curve [AUC] 77-92%), except for the hand metacarpal. Distal radius and calcaneus measurements (ORs = 2.4 and 3.0) were the best discriminators of hip fracture patients from controls. Using a forward selective linear regression model, the discriminator values of combined assessment at two sites were investigated. There was moderate improvement in diagnostic value, but the best combination was the calcaneus with the distal radius, which improved the AUC by 3% and raised both the sensitivity and specificity to 94%. These data demonstrate the encouraging potential of improving discrimination of hip fracture by using multiple-site ultrasonic measurements.
Assuntos
Osso e Ossos/diagnóstico por imagem , Fraturas do Quadril/diagnóstico por imagem , Ultrassonografia/instrumentação , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas do Quadril/diagnóstico , Fraturas do Quadril/etiologia , Humanos , Osteoporose/complicações , Osteoporose/diagnóstico , Osteoporose/diagnóstico por imagem , Sensibilidade e Especificidade , Ultrassonografia/estatística & dados numéricosRESUMO
In this study we explore the hypothesis that estimates of failure loads in the thoracic spine by lumbar dual energy X-ray absorptiometry (DXA) are compromised of skeletal heterogeneity throughout the spine and artifacts of spinal DXA. We studied the correlation between mechanical failure loads of thoracic and lumbar vertebrae, and that of in situ vs. ex situ lumbar DXA with thoracic and lumbar fracture loads, respectively. One hundred and nineteen subjects (76 female, age 82+/-9yr; 43 male, age 77+/-11yr) were examined under in situ conditions (anterior-posterior direction), the scans being repeated ex situ (lateral projection) in 68 cases. The failure loads of thoracic vertebrae (T) 6 and 10, and lumbar vertebra (L) 3 were determined in axial compression, using a functional 3-segment unit. The correlation between thoracic failure loads (T6 vs. T10) was significantly (p<0.01) higher (r=0.85) than those between thoracic and lumbar vertebrae (r=0.68 and 0.61, respectively). Lateral ex situ DXA displayed a significantly higher correlation (p<0.05) with lumbar vertebral fracture loads than in situ anterior-posterior DXA (r=0.85 vs. 0.71), but the correlation of thoracic failure loads with lateral ex situ lumbar DXA was similar to that obtained in situ in anterior-posterior direction (r=0.69 vs. 0.69 for T10, and r=0.61 vs. 0.65 for T6). The correlation between fracture loads of different spinal segments, and between DXA and failure loads was not significantly different between men and women. The results demonstrate a substantial heterogeneity of mechanical competence throughout the spine in elderly individuals. Because of the high incidence of fractures in the thoracic spine, these findings suggest that, clinically, lateral DXA involves no relevant advantage over anterior-posterior measurements of the lumbar spine.
Assuntos
Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/fisiologia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Densidade Óssea , Força Compressiva , Feminino , Humanos , Técnicas In Vitro , MasculinoRESUMO
We investigated a new multisite quantitative ultrasound device that measures the acoustic velocity in axial transmission mode along the cortex. Using a prototype of the Omnisense (Sunlight Ultrasound Technologies, Rehovot, Israel), we tested the performance of this instrument at four sites of the skeleton: radius, ulna, metacarpal, and phalanx. Intraobserver (interobserver) precision errors ranged from 0.2% to 0.3% (0.3% to 0.7%) for triplicate measurements with repositioning. Fracture discrimination was tested by comparing a group of 34 women who had previously suffered a fracture of the hip, spine, ankle, or forearm to a group of 28 healthy women who had not suffered a fracture. Age-adjusted standardized odds ratios ranged from 1.6 to 4.5. Except for the ulna the sites showed a significant fracture discrimination (p < 0.01). The areas under the receiver operating curves (ROC) curves were from 0.88 to 0.89 for radius, metacarpal, and phalanx. A combination of the results from the three sites showed a significant increase of the ROC area to 0.95 (p < 0. 05). Our results show promising performance of this new device. The ability to measure a large variety of sites and the potential to combine these measurements are promising with regard to optimizing fracture risk assessment.
Assuntos
Osso e Ossos/diagnóstico por imagem , Fraturas Ósseas/diagnóstico por imagem , Ultrassonografia/instrumentação , Idoso , Estudos de Avaliação como Assunto , Feminino , Humanos , Modelos Logísticos , Variações Dependentes do Observador , Osteoporose/complicações , Osteoporose/diagnóstico por imagem , Projetos Piloto , Curva ROC , Ultrassonografia/estatística & dados numéricosRESUMO
Quantitative ultrasound (QUS) methods are promising tools for the assessment of the bone status in osteoporosis. The techniques are based on changes in speed and amplitude of a broadband ultrasound signal propagating through the bone. However, ultrasound propagation through the anisotropic bone is complex and cannot be described in a simple way. The devices are easy to use, inexpensive, portable, do not use ionizing radiation, and therefore have advantages compared to conventional densitometry. This review discusses the technical basics, current research, clinical applications, points of weakness, and future prospects of QUS. For better understanding ultrasound propagation through bone is visualized with a simulation software.
Assuntos
Osso e Ossos/diagnóstico por imagem , Osteoporose/diagnóstico por imagem , Ultrassonografia/instrumentação , Calcâneo/diagnóstico por imagem , Simulação por Computador , Densitometria , Previsões , Fraturas Ósseas/etiologia , Humanos , Osteoporose/complicações , Imagens de Fantasmas , Prognóstico , Pesquisa , Risco , Fatores de Risco , SoftwareRESUMO
In recent years Quantitative Ultrasound (QUS) approaches have increasingly been used for the assessment of osteoporosis. Extensive study results exist for the estimation of osteoporotic fracture risk. Also, results exist for the analysis of properties which characterize osteoporosis--low bone mass and deterioration of bone architecture. However, the existence of different methods, devices and parameters has to be taken into account. Moreover, the status of the evaluation is different for each type of device. Measures of quality assurance and in-depth knowledge about limitations of the approach are of substantial importance for clinical use. Because of the lack of ionising radiation and their lower cost, QUS approaches--if used appropriately--can play an important role in the assessment of osteoporotic fracture risk.
Assuntos
Osteoporose/diagnóstico por imagem , Densidade Óssea , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/etiologia , Humanos , Osteoporose/complicações , Osteoporose/fisiopatologia , Fatores de Risco , UltrassonografiaRESUMO
The rapid development of Quantitative Ultrasound (QUS) methods in recent years allows to use these devices in a clinical setting. Their primary role is the assessment of fracture risk due to osteoporosis. Further investigations are required for use of QUS for monitoring and diagnostic purposes. Differences between the QUS parameters, Speed of Sound (SOS) and Broadband Ultrasound Attenuation (BUA), between different measurement sites and measurement technology need to be appreciated. Consequently, QUS devices need to be validated individually. In addition, adequate quality assurance measures need to be implemented. QUS and bone densitometry have different complementing features and both should find their place in the clinical arena. These recent developments open up the opportunity to reduce the number of fractures by targeted diagnostic assessments which should lead to medical progress and should also bring along socio-economical advantages.
Assuntos
Processamento de Imagem Assistida por Computador/instrumentação , Osteoporose/diagnóstico por imagem , Ultrassonografia/instrumentação , Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Humanos , Imagens de Fantasmas , Sensibilidade e EspecificidadeRESUMO
Our objective is to evaluate an ultrasound probe for measurements of velocity and anisotropy in human cortical bone (tibia). The anisotropy of cortical bone is a known and mechanically relevant property in the context of osteoporotic fracture risk. Current in vivo quantitative ultrasound devices measuring the velocity of ultrasound in long bones can only be applied in the axial direction. For anisotropy measurements a second direction for velocity measurements preferably perpendicular to the axial direction is necessary. We developed a new ultrasound probe which permits axial transmission measurements with a simultaneous second perpendicular direction (tangential). Anisotropy measurements were performed on isotropic and anisotropic phantoms and two excised human female tibiae (age 63 and 82). Anisotropy ratios (AI; ratio of squared ultrasound velocities in the two directions) were for the isotropic phantom 1.06 ± 0.01 and for the anisotropic phantom 1.14 ± 0.03 (mean ± standard deviation). AI was 1.83 ± 0.29 in the tibia from the older donor and 1.37 ± 0.18 in the tibia from the younger donor. The AIs were in the expected range and differed significantly (p<0.05, t-test) between the tibiae. Measured sound velocities were reproducible (mean standard deviation of short time precision of both channels for phantom measurements 31 m/s) and in agreement with reported velocities of the phantom material. Our results document the feasibility of anisotropy measurements at long bones using a single probe. Further improvements in the design of the probe and tests in vivo are warranted. If this approach can be evaluated in vivo an additional tool for assessing the bone status is available for clinical use.
Assuntos
Técnicas de Imagem por Elasticidade/instrumentação , Aumento da Imagem/instrumentação , Tíbia/diagnóstico por imagem , Tíbia/fisiologia , Transdutores , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Módulo de Elasticidade/fisiologia , Desenho de Equipamento , Análise de Falha de Equipamento , Feminino , Humanos , Técnicas In Vitro , Pessoa de Meia-Idade , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The aim of this in vitro study is to evaluate the potentiality of quantitative ultrasound (QUS) to separate information on density, elasticity, and structure on specimens of trabecular bone. Fifteen cylinders of spongy bone extracted from equine vertebrae were progressively demineralized and subjected to QUS, micro computed tomography (muCT), Dual energy X-ray absorptiometry (DXA) at various mineralization levels. Eventually all cylinders underwent a compression test to calculate the Young's modulus. Correlation analysis shows that speed of sound (SOS) is strictly associated to bone mineral density (BMD), Young's modulus, and all muCT parameters except for degree of anisotropy (DA). Fast wave amplitude (FWA) is directly correlated with bone surface and total volume ratio (BS/TV) and trabecular separation (Tb Sp), and inversely correlated with trabecular number (Tb N). Because muCT parameters were strictly correlated to BMD and Young's modulus data, partial correlation analysis was performed between SOS, FWA, and structural and elastic data in order to eliminate the effect of density. SOS was significantly correlated to bone volume and total volume ratio (BV/TV), BS/TV, and Young's modulus, and FWA was significantly correlated to Tb Sp only. These results show that SOS is strongly influenced by volumetric mineral bone density and elastic modulus of the specimen, and FWA is mainly affected by trabecular separation independently on density. Therefore, SOS and FWA are able to provide different and complementary information, at least on trabecular bone samples.