RESUMO
Trabecular bone score (TBS) is an indirect and noninvasive measure of bone quality. A low TBS indicates degraded bone microarchitecture, predicts osteoporotic fracture, and is partially independent of clinical risk factors and bone mineral density (BMD). There is substantial evidence supporting the use of TBS to assess vertebral, hip, and major osteoporotic fracture risk in postmenopausal women, as well as to assess hip and major osteoporotic fracture risk in men aged > 50 years. TBS complements BMD information and can be used to adjust the FRAX (Fracture Risk Assessment) score to improve risk stratification. While TBS should not be used to monitor antiresorptive therapy, it may be potentially useful for monitoring anabolic therapy. There is also a growing body of evidence indicating that TBS is particularly useful as an adjunct to BMD for fracture risk assessment in conditions associated with increased fracture risk, such as type-2 diabetes, chronic corticosteroid excess, and other conditions wherein BMD readings are often misleading. The interference of abdominal soft tissue thickness (STT) on TBS should also be considered when interpreting these findings because image noise can impact TBS evaluation. A new TBS software version based on an algorithm that accounts for STT rather than BMI seems to correct this technical limitation and is under development. In this paper, we review the current state of TBS, its technical aspects, and its evolving role in the assessment and management of several clinical conditions.
Assuntos
Osso Esponjoso , Fraturas por Osteoporose , Masculino , Feminino , Humanos , Fraturas por Osteoporose/etiologia , Fraturas por Osteoporose/prevenção & controle , Absorciometria de Fóton , Medição de Risco , Densidade Óssea , Vértebras LombaresRESUMO
ABSTRACT Trabecular bone score (TBS) is an indirect and noninvasive measure of bone quality. A low TBS indicates degraded bone microarchitecture, predicts osteoporotic fracture, and is partially independent of clinical risk factors and bone mineral density (BMD). There is substantial evidence supporting the use of TBS to assess vertebral, hip, and major osteoporotic fracture risk in postmenopausal women, as well as to assess hip and major osteoporotic fracture risk in men aged > 50 years. TBS complements BMD information and can be used to adjust the FRAX (Fracture Risk Assessment) score to improve risk stratification. While TBS should not be used to monitor antiresorptive therapy, it may be potentially useful for monitoring anabolic therapy. There is also a growing body of evidence indicating that TBS is particularly useful as an adjunct to BMD for fracture risk assessment in conditions associated with increased fracture risk, such as type-2 diabetes, chronic corticosteroid excess, and other conditions wherein BMD readings are often misleading. The interference of abdominal soft tissue thickness (STT) on TBS should also be considered when interpreting these findings because image noise can impact TBS evaluation. A new TBS software version based on an algorithm that accounts for STT rather than BMI seems to correct this technical limitation and is under development. In this paper, we review the current state of TBS, its technical aspects, and its evolving role in the assessment and management of several clinical conditions.
RESUMO
BACKGROUND: Type 2 diabetes (T2D) is associated with increased fracture risk, despite similar or greater BMD compared to nondiabetics. TBS predicts fracture risk in T2D and nondiabetics. However, increased abdominal thickness, a common feature in T2D, may reduce TBS values. AIM: To study the relationship among glycemic status, BMD and TBS, considering abdominal soft tissue thickness (STT) interference. METHODS: Cross-sectional analysis of 493 women ≥65 years, with simultaneous DXA scans and HbA1c measures. STT and TBS (iNsight Software, v3.0) were derived from lumbar spine (LS) scans. Subjects were divided according to HbA1c levels: 1 (≥6.5%; n = 116), 2 (5.7-6.4%; n = 217) and 3 (≤5.6%; n = 160). Group 1 was further divided based on HbA1c and/or disease duration: 1a (HbA1c ≥ 7.5%; n = 42), 1b (HbA1c ≥ 6.5% and disease duration ≥5 years; n = 63) and 1c (HbA1c ≥ 7.5% and disease duration ≥5 years; n = 30). FINDINGS: For the entire cohort, mean age, TBS, BMI and STT were 71.8 ± 6.0 years, 1.299 ± 0.101, 26.9 ± 4.1 kg/m2, and 21.4 ± 2.9 cm, respectively. LS-BMD was similar among groups. BMD in hip sites and STT were higher in group 1. TBS was lower in patients with higher HbA1c (P = 0.020), with a mean TBS in groups 1, 2, and 3 of 1.280, 1.299 and 1.314, respectively. This difference remained after adjusting for age, LS-BMD and BMI (P = 0.010). After replacing BMI with STT, TBS differences were no longer significant (P = 0.270). The same was observed when subgroups 1a and 1b were compared to group 3. However, for subgroup 1c, TBS remained lower compared to group 3, even after adjusting for age, LS-BMD and STT, with a borderline P-value (1.275 vs. 1.308; P = 0.047). CONCLUSION: Higher HbA1c levels were associated with greater BMD in hip sites, higher abdominal STT and lower TBS values. However, after including the STT in the adjustment, TBS differences among groups disappeared, except in women with higher HbA1c levels and longer disease duration.
Assuntos
Diabetes Mellitus Tipo 2 , Fraturas Ósseas , Fraturas por Osteoporose , Absorciometria de Fóton , Idoso , Densidade Óssea , Osso Esponjoso/diagnóstico por imagem , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Feminino , Fraturas Ósseas/complicações , Hemoglobinas Glicadas , Humanos , Vértebras Lombares/diagnóstico por imagem , Fraturas por Osteoporose/complicações , Pós-MenopausaAssuntos
Osteoporose , Fraturas por Osteoporose , Feminino , Humanos , Osteoporose/epidemiologia , Pré-MenopausaRESUMO
CONTEXT: Bone loss is a constant finding in patients with spinal cord injury (SCI). OBJECTIVE: We sought to evaluate potential modifiable factors that could lead to bone loss in complete motor paraplegia by examining gonadal axis hormones, vitamin D status, and bone markers. DESIGN: This is a cross sectional. SETTING: It includes SCI Outpatient. PATIENTS AND OTHER PARTICIPANTS: Twenty-nine chronic male patients with SCI were compared with 17 age-matched, able-bodied men. MAIN OUTCOME MEASURE: The bone mineral density (BMD) of lower limbs and lumbar spine were measured using dual x-ray absorptiometry. Parathormone, 25-hydroxyvitamin D [25(OH)D], collagen type I C-terminal telopeptide (CTX), and sexual hormone were measured. RESULTS: Patients with SCI had lower BMD at the inferior limbs sites. CTX showed an inverse relationship with the time since injury. Patients had lower free T levels (SCI, 12.00 ± 2.91 vs controls, 19.51 ± 5.72; P ≤ .001), and the majority (72%) had normal/low levels of gonadotropins. Low T, however, was not related to low bone mass in patients with SCI. In the controls, the 25(OH)D level was positively correlated with the T and with the lumbar spine BMD, but these correlations were not observed in the SCI. CONCLUSIONS: Impairment of testicular function after SCI was indicated by the low levels of T and the loss of correlation between T and 25(OH)D levels; this correlation was present in the able-bodied controls. Inappropriate levels of gonadotropins were identified in most patients, featuring a hypogonadotropic hypogonadism and suggesting a disruption of the pituitary-gonadal axis. T concentrations might not be an effective target for bone loss therapy.
Assuntos
Osso e Ossos/patologia , Hormônios Esteroides Gonadais/sangue , Gônadas/fisiopatologia , Traumatismos da Medula Espinal/sangue , Traumatismos da Medula Espinal/fisiopatologia , Absorciometria de Fóton , Adolescente , Adulto , Colágeno Tipo I/sangue , Estudos Transversais , Humanos , Masculino , Pessoa de Meia-Idade , Paraplegia/sangue , Paraplegia/fisiopatologia , Hormônio Paratireóideo/sangue , Peptídeos/sangue , Traumatismos da Medula Espinal/patologia , Vitamina D/sangue , Adulto JovemRESUMO
Osteoporosis (OP) in spinal cord injury (SCI) patients is a secondary process in which numerous factors are involved. Diagnosing OP and the threshold for fractures in this population, based on bone mineral density (BMD) measured by double energy X-ray absorptiometry (DXA), is still a challenge. The aim of this study was to evaluate bone mineral loss by DXA, its relationship with body composition and fracture incidence, in complete paraplegics patients, compared with aged-matched controls; we include a nonstandard bone site, the distal femur, and describe the technical and practical aspects of this procedure. Twenty-five SCI patients were included in the study and 17 subjects as control group. No prior or recent fractures were observed in X-ray analysis. The BMD of all femoral sites was significantly lower in patients than in controls (femoral neck, total femur, and distal femur); no difference was observed between BMD of the lumbar spine of patients and controls. We found inverse relationship between time of SCI and bone mineral mass only for distal femur BMD. We conclude that the distal femur is a more sensitive bone site for assessing bone loss by DXA, in SCI patients, than the proximal femoral sites.
RESUMO
OBJECTIVE: In patients with primary hyperparathyroidism, candidates for surgical intervention, the parathyroid pre-operative localization is of fundamental importance in planning the appropriate surgical approach. MATERIALS AND METHODS: The additional acquisition of SPECT and Technetium-99m images, during parathyroid scintigraphy with Sestamibi, is not common practice. Usually, only planar image acquisition, 15 minutes prior and 2 hours after radiopharmaceutical administration, is performed. RESULTS: In our experience, the complete protocol in parathyroid scintigraphy increases the accuracy of pre-operative parathyroid localization. CONCLUSION: The complete utilization of all available nuclear medicine methods (SPECT e 99mTc) and image interpretation in a multidisciplinary context can improve the accuracy of parathyroid scintigraphy.
Assuntos
Adenoma/diagnóstico por imagem , Adenoma/patologia , Neoplasias das Paratireoides/diagnóstico por imagem , Neoplasias das Paratireoides/patologia , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único/normas , Adulto , Idoso , Protocolos Clínicos/normas , Feminino , Humanos , Masculino , Cuidados Pré-Operatórios/métodos , Cuidados Pré-Operatórios/normas , Estudos RetrospectivosRESUMO
OBJETIVO: Diante de um paciente portador de hiperparatiroidismo primário com indicação de tratamento cirúrgico, a localização pré-operatória da paratiroide é de fundamental importância para definir a melhor abordagem cirúrgica. MATERIAIS E MÉTODOS: A realização adicional de imagens SPECT e da cintilografia com 99mTc durante a cintilografia das paratiroides com Setamibi não é rotina em nosso meio, sendo comum a aquisição apenas das imagens planas − precoce (15 minutos) e tardia (2 horas). RESULTADOS: Na nossa experiência, tem-se percebido que a realização do protocolo completo contribui de maneira decisiva na sensibilidade da localização pré-operatória da paratiroide. CONCLUSÃO: A aplicação completa de todos os métodos cintilográficos disponíveis (SPECT e 99mTc) e a análise cuidadosa das imagens em um contexto multidisciplinar podem aumentar a acurácia da cintilografia das paratiroides.
OBJECTIVE: In patients with primary hyperparathyroidism, candidates for surgical intervention, the parathyroid pre-operative localization is of fundamental importance in planning the appropriate surgical approach. MATERIALS AND METHODS: The additional acquisition of SPECT and Technetium-99m images, during parathyroid scintigraphy with Sestamibi, is not common practice. Usually, only planar image acquisition, 15 minutes prior and 2 hours after radiopharmaceutical administration, is performed. RESULTS: In our experience, the complete protocol in parathyroid scintigraphy increases the accuracy of pre-operative parathyroid localization. CONCLUSION: The complete utilization of all available nuclear medicine methods (SPECT e 99mTc) and image interpretation in a multidisciplinary context can improve the accuracy of parathyroid scintigraphy.
Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Adenoma/patologia , Adenoma , Neoplasias das Paratireoides/patologia , Neoplasias das Paratireoides , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único/normas , Protocolos Clínicos/normas , Cuidados Pré-Operatórios/métodos , Cuidados Pré-Operatórios/normas , Estudos RetrospectivosRESUMO
With the evolution of bone densitometry, differences in technologies, acquisition techniques, reference databases, reporting methods, diagnostic criteria and terminology have developed and the International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences, the latest in 2007. The Brazilian Society for Clinical Densitometry (SBDens), with support from many Brazilian societies interested in bone health, gathered numerous specialists to discuss the ISCD proposals and to evaluate the validity of the extension of those norms to Brazilian population. The SBDens reunion of consensus made a very useful document to help the understanding and interpretation of bone densitometry and other methods of bone assessment.
Assuntos
Densidade Óssea , Densitometria/métodos , Adolescente , Adulto , Brasil , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sociedades Médicas , Adulto JovemRESUMO
A evolução dos métodos de avaliação da massa óssea trouxe diferentes tecnologias, modos de aquisição de imagens, bancos de dados de referência, terminologias, critérios diagnósticos fez com que a International Society for Bone Densitometry (ISCD) tomasse a iniciativa de promover reuniões periódicas de consenso, a última em 2007. A Sociedade Brasileira de Densitometria Clínica (SBDens), com apoio de várias sociedades brasileiras ligadas ao estudo da saúde óssea, reuniu diversos especialistas para discutir as propostas da ISCD e validar a aplicação destas normas à população brasileira. A reunião de Posições Oficiais da SBDens produziu um documento extremamente útil para a compreensão e interpretação da densitometria e de outros métodos de avaliação da massa óssea.
With the evolution of bone densitometry, differences in technologies, acquisition techniques, reference databases, reporting methods, diagnostic criteria and terminology have developed and the International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences, the latest in 2007. The Brazilian Society for Clinical Densitometry (SBDens), with support from many Brazilian societies interested in bone health, gathered numerous specialists to discuss the ISCD proposals and to evaluate the validity of the extension of those norms to Brazilian population. The SBDens reunion of consensus made a very utile document to help the understanding and interpretation of bone densitometry and other methods of bone assessment.
Assuntos
Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Densidade Óssea , Densitometria/métodos , Brasil , Sociedades Médicas , Adulto JovemRESUMO
A necessidade de uma melhor compreensão do metabolismo ósseo tornou-se crescente na Odontologia. O advento da implantodontia demandou a busca por boas condições de tecido ósseo visando à colocação de implantes osseointegráveis e também pela necessidade de preparo prévio de leitos receptores em áreas que necessitam de enxerto ósseo até as grandes reconstruções no campo da cirurgia buco-maxilo-facial que buscam reconstruir estruturas ósseas perdidas decorrentes de trauma ou de destruição tumoral tendo como área doadora a região ilíaca. A osteocalcina, produto da ação osteoblástica, intimamente relacionada à mineralização da matriz óssea tem sua ação estimulada pela vitamina D3 e é imprescindível para o processo de mineralização do tecido ósseo. Neste trabalho procurou-se fazer uma revisão dos aspectos mais importantes relacionados à atuação destas duas substâncias no metabolismo ósseo.
The need of a better understanding of the bone metabolism became growing in Dentistry. The coming of the implantology demanded the search for good conditions of bone tissue seeking to the placement of implants and also for the need of previous preparation in order to receive bone grafts in areas that need bone to great reconstructions in the of maxillofacial surgery which looks upon to rebuild bone structures lost by trauma or tumoral damages, which tends as donor area, the iliac bone. The osteocalcin, product of the osteoblastic action, intimately related to the mineralization of the bone matrix, keeps its action stimulated by the vitamin D3 and is indispensable for the process of the bone tissue mineralization. This paper intend to a revision of the most important aspects related to the performance of these two substances in the bone metabolism.
RESUMO
Osteoporosis is a disease characterized by low bone mass and micro architectural alterations of bone tissue leading to enhanced bone fragility and increased fracture risk. Although research in osteoporosis has focused mainly on the role of bone loss in the elderly population, it is becoming increasingly clear that the amount of bone that is gained during growth is also an important determinant of future resistance to fractures. Thus, considerable interest is being placed on defining preventive strategies that optimize the gain of bone mass during childhood and adolescence. Knowledge of the determinants accounting for the physiologic and genetic variations in bone accumulation in children will provide the best means toward the early diagnosis and treatment of osteoporosis. This article reviews the techniques available for bone mass measurements in children and the major determinants and diseases influencing bone accretion during childhood and adolescence.
Assuntos
Densidade Óssea/fisiologia , Osteoporose/diagnóstico , Absorciometria de Fóton , Adolescente , Desenvolvimento Ósseo/fisiologia , Criança , Humanos , Osteoporose/etiologia , Osteoporose/prevenção & controle , Fatores de RiscoRESUMO
Osteoporosis is a disease characterized by low bone mass and micro architectural alterations of bone tissue leading to enhanced bone fragility and increased fracture risk. Although research in osteoporosis has focused mainly on the role of bone loss in the elderly population, it is becoming increasingly clear that the amount of bone that is gained during growth is also an important determinant of future resistance to fractures. Thus, considerable interest is being placed on defining preventive strategies that optimize the gain of bone mass during childhood and adolescence. Knowledge of the determinants accounting for the physiologic and genetic variations in bone accumulation in children will provide the best means toward the early diagnosis and treatment of osteoporosis. This article reviews the techniques available for bone mass measurements in children and the major determinants and diseases influencing bone accretion during childhood and adolescence.
Osteoporose é uma doença caracterizada pela baixa massa óssea e alterações de micro arquitetura do tecido ósseo, levando ao aumento da fragilidade óssea e aumento do risco de fratura. Apesar da pesquisa em osteoporose ter focalizado principalmente no papel da perda óssea na população idosa, está começando a ficar claro que a quantidade de osso que é ganho durante o crescimento é também um determinante importante de resistência futura para fraturas. Portanto, interesse considerável está sendo colocado na definição de estratégias preventivas que otimizam o ganho de massa óssea durante a infância e adolescência. O conhecimento dos determinantes responsáveis pelas variações fisiológicas e genéticas, na acumulação óssea nas crianças, irá levar aos melhores meios para o diagnóstico precoce e tratamento da osteoporose. Este artigo revê as técnicas disponíveis para a medida da massa óssea em crianças e os maiores determinantes e doenças que influenciam a aquisição óssea durante a infância e adolescência.
Assuntos
Humanos , Criança , Adolescente , Densidade Óssea/fisiologia , Osteoporose/diagnóstico , Absorciometria de Fóton , Desenvolvimento Ósseo/fisiologia , Osteoporose/etiologia , Osteoporose/prevenção & controle , Fatores de RiscoRESUMO
O hiperparatiroidismo primário (HPP) é caracterizado pelo aumento da secreção de PTH, com conseqüente aumento da concentração sérica de cálcio. O diagnóstico é realizado pela dosagem de cálcio e PTH. A cintilografia das paratiróides é solicitada, classicamente, em pacientes com recorrência de HPP após paratiroidectomia, na tentativa de detectar glândulas patológicas ectópicas ou remanescentes. Algumas vezes este exame tem sido solicitado antes do primeiro ato cirúrgico, na tentativa de localizar as glândulas comprometidas e abreviar a duração da cirurgia; na nossa casuística, no entanto, a maioria dos exames solicitados com esta indicação resulta negativa. Comparamos os níveis séricos de cálcio e PTH nos pacientes com cintilografia das paratiróides positiva, com aqueles dos pacientes com cintilografia negativa, a fim de tentar definir níveis com índice maior de positividade na cintilografia. Foram estudados retrospectivamente 74 pacientes consecutivos submetidos à cintilografia das paratiróides. Avaliou-se a utilização dos valores mais baixos de PTH (79pg/mL) e cálcio (l0mg/dL) registrados no grupo com cintilografia positiva como referência para a indicação do exame. No grupo total de pacientes, 17 (23 por cento) apresentaram cintilografia positiva. No subgrupo com valores de PTH >79pg/mL e de cálcio >_10 mg/dL a porcentagem de exames positivos foi de 49 por cento. Concluímos que cintilografias das paratiróides realizadas antes da cirurgia de paratiroidectomia em pacientes com níveis de cálcio sérico abaixo do limite superior da normalidade ou níveis de PTH pouco aumentados são, na maioria das vezes, negativas.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Cálcio , Hiperparatireoidismo , Hormônio Paratireóideo , Cintilografia , CreatininaRESUMO
A massa óssea de um indivíduo adulto, que está estreitamente relacionada ao risco de fraturas osteoporóticas, depende da diferença entre o pico de massa óssea alcançada no final do período de maturação sexual e esquelética, e as perdas acumuladas durante a vida. A enorme variabilidade observada no pico de massa óssea da adolescência está relacionada, principalmente, a fatores genéticos, mas também a parâmetros antropométricos, como peso e altura, hábitos dietéticos, influências hormonais diversas, atividade física, uso de medicamentos e doenças intercorrentes. A identificação dos fatores envolvidos na aquisição do pico de massa óssea na infância e adolescência e a compreensão deste longo período de maturação esquelética, permitirão a criação de estratégias para prevenção da osteoporose.