Association of Severity of Coronary Lesions with Bone Mineral Density in Postmenopausal Women / Associação entre Gravidade das Lesões Coronarianas e Densidade Mineral Óssea em Mulheres Pós-Menopausa

Abstract Background: Coronary artery disease (CAD) and osteoporosis (OP) are common diseases in postmenopausal women. In both cross-sectional and longitudinal epidemiologic studies, low bone mass has been related to increased frequency of CAD. However, available data on the relationship between bone mineral density (BMD) and severity of coronary lesions is limited. Objective: To investigate association between the BMD and severity of coronary lesions assessed by Gensini score in postmenopausal women. Methods: This study included 122 postmenopausal women who were diagnosed with CAD. These patients were divided into two groups according to the severity of coronary lesions assessed by the Gensini score - patients with mild coronary lesions (Gensini score < 25) and patients with severe coronary lesions (Gensini score ≥ 25). Femoral neck mineral density was measured with dual energy X-ray absorptiometry (DXA). Results: The study included postmenopausal women aged 64.31 ± 4.71 years, 85 of whom (69.7%) exhibited severe coronary lesions. Participants with severe coronary lesions had a significantly higher T score than did those with mild coronary lesions at the femoral neck (p < 0.05). The mean T-score was −0.84 ± 1.01 in mild coronary lesions group, −1.42 ± 1.39 in severe coronary lesions group (p < 0.05). Multivariable logistic regression analysis showed that osteopenia-osteoporosis at the Femoral neck (odds ratio 2.73; 95% confidence interval 1.06 to 6.13) was associated with an increased risk of developing severe coronary lesions. The multiple regression model showed that T-scores (b = −0.407, SE = 0.151, p=0.007) were the independent predictors of Gensini score. Conclusion: The relationship between severity of coronary lesions and BMD was significant in postmenopausal women. BMD, a low-cost technique involving minimal radiation exposure, widely used for osteoporosis screening, is a promising marker of severity of coronary lesions.

Resumo Fundamento: A doença arterial coronariana (DAC) e a osteoporose são doenças comuns em mulheres pós-menopausa. Tanto em estudos transversais como em estudos epidemiológicos longitudinais, a massa óssea diminuída foi relacionada à frequência aumentada de DAC. No entanto, dados disponíveis sobre a relação entre densidade mineral óssea (DMO) e gravidade das lesões coronarianas são limitados. Objetivo: Investigar a associação entre DMO e gravidade das lesões coronarianas avaliadas pelo escore de Gensini em mulheres pós-menopausa. Métodos: Este estudo incluiu 122 mulheres pós-menopausa diagnosticadas com DAC. As pacientes foram divididas em dois grupos de acordo com a gravidade das lesões coronarianas avaliada pelo escore de Gensini - pacientes com lesões coronarianas leves (escore de Gensini < 25) e pacientes com lesões coronarianas graves (escore de Gensini ≥ 25). A densidade mineral do colo femoral foi medida por absorção de raios-X de dupla energia (DXA). Resultados: O estudo incluiu mulheres pós-menopausa com idade de 64,31 ± 4,71 anos, 85 delas (69,7%) com lesões coronarianas graves. Pacientes com lesões coronarianas graves apresentaram um escore T mais elevado que aquelas com lesões coronarianas leves no colo femoral (p < 0,05). O escore T médio foi -0,84 ± 1,01 no grupo com lesões leves, e -1,42 ± 1,39 no grupo com lesões graves (p < 0,05). A análise de regressão logística multivariada mostrou que a osteopenia-osteoporose no colo femoral (odds ratio 2,73; intervalo de confiança de 95% 1,06 - 6,13) esteve associada com um risco aumentado de se desenvolver lesões coronarianas graves. O modelo de regressão múltipla mostrou que os escores T (b = -0,407; EP= 0,151; p = 0,007) foram preditores independentes do escore de Gensini. Conclusão: Encontrou-se uma relação significativa entre a gravidade das lesões coronarianas e a DMO em mulheres pós-menopausa. DMO, uma técnica de baixo custo que envolve mínima exposição à radiação, e amplamente utilizada no rastreamento de osteoporose, é um marcador promissor da gravidade de lesões coronarianas graves.

Desmineralização óssea – uma ferramenta clínica para potencializar o reparo / Bone demineralization – a clinical tool for improving bone healing

O emprego da desmineralização óssea in situ nos diferentes procedimentos regenerativos ainda não é comum em Periodontia e Cirurgia maxilofacial, mas pesquisas comprovando o aumento na presença de proteínas ósseas morfogenéticas (BMPs) após o processo de desmineralização óssea, levam a considerar que esse procedimento é vantajoso no aumento da previsibilidade dos procedimentos regenerativos. As BMPs e outros fatores de crescimento liberados pelo processo de desmineralização óssea funcionam iniciando o recrutamento e a diferenciação de células progenitoras. Assim, promovem a maturação dessas células em condrócitos, osteoblastos e osteócitos. Esta revisão de literatura procurou esclarecer os mecanismos pelos quais a desmineralização óssea in situ pode favorecer os procedimentos ósseos regenerativos, chegando-se à conclusão de que o processo de desmineralização aumenta a velocidade de reparação e osteoindução, proporcionando substrato para a proliferação e diferenciação de células osteoprogenitoras.

Análisis geométrico de la arquitectura trabecular de un hueso de bovino durante el proceso inducido de desmineralización / Geometric analysis of the trabecular architecture in a bovine bone during the process of induced demineralization

La masificación de la radiología digital ha hecho posible el estudio de diferentes patologías mediante imágenes de alta calidad diagnóstica. Existen diferentes patologías que afectan al tejido óseo, y que producen pérdida del mineral(1). Aquellas patologías se caracterizan por la pérdida de la arquitectura trabecular y un adelgazamiento de la cortical(7), visibles en la radiología. Aquellos cambios llevan al paciente a caer en el riesgo de sufrir futuras fracturas(8), por lo que se considera importante realizar un análisis de la geometría de las trabéculas ante este tipo de patología, con el fin de prever riesgos de fractura. Material y Métodos. Para realizar este estudio, se escogió un fémur de bovino(19). Este fue sumergido en ácido acético al 4 por ciento, con el fin de producir su desmineralización. Se le realizó una medición cada 24 horas mediante la adquisición de imágenes radiológicas, que fueron obtenidas con un equipo digital directo hasta observar cambios radiológicos evidentes en la población trabecular. Las imágenes fueron evaluadas mediante un software de libre acceso llamado ImageJ®(23), realizando mediciones trabeculares mediante la herramienta ROI, y se adquirieron los valores de área, perímetro y circularidad. Resultados. En las 10 trabéculas estudiadas se observaron y cuantificaron cambios en la arquitectura trabecular, aumentando el área en un 124 por ciento, el perímetro en un 53 por ciento y la circularidad se mantuvo en promedio constante. Conclusiones: Mediante la radiología digital, es posible evaluar la arquitectura trabecular mediante parámetros geométricos, los cuales nos indican que existen cambios muy pequeños a lo largo del tiempo. Se observó un aumento de tamaño en las trabéculas, pero sin pérdida de su forma.

Introduction. The mass use of digital radiology has made possible the study of different pathologies through high quality diagnostic images. There are different diseases that affect bone tissue and which produce mineral loss (1). Those diseases are characterized by loss of trabecular architecture and cortical thinning (7), visible in radiology. Those changes lead the patient to suffer the risk of future fractures (8), therefore it is considered important to analyze the geometry of the trabeculae in this kind of pathology in order to anticipate fracture risk. Material and Methods. For this study, a bovine's femur was chosen(19). This was immersed in 4 percent acetic acid to produce demineralization. Measurement was performed (in Clinica Alemana Santiago) every 24 hours by radiological imagings, which were obtained with digital radiology (DR) to observe obvious radiological changes in trabecular population. The images were evaluated by a freely available software called ImageJ® (23), by performing Trabecular measurements using the ROI tool, acquiring the values of area, perimeter and circularity. Results. In the 10 trabeculae studied, we observed and quantified changes in trabecular architecture, increasing the value of average area in 124 percent, perimeter in 53 percent and no change in circularity during the demineralization process. Conclusions. With digital radiography, it is possible to evaluate the trabecular architecture using geometric parameters, which indicate that there are very small changes over time. An increase in size of the trabeculae was observed, trabeculae was observed, but without loss of shape.

The behavior of demineralized bone matrix (DBM) in post-extraction sockets / El comportamiento de matriz ósea desmineralizada (DBM) en alvéolos post-extracción

Autogenous bone grafts are considered to be the gold standard in bone regeneration because of their osteogenic activity; however, due to limited availability of intraoral donor sites and the need to resolve the demands of patients requires an alternative to these. Two male patients were submitted to implant surgery in two stages with 6 months intervals between each of them: the first was exodontia and placement of DBM graft into the socket; the second stage was the drill with a 2 mm internal diameter trephine in center of the alveolar ridge previously grafted with DBM and subsequent implant placement. The samples were analyzed under histological techniques. A very mature bone was observed at 6 months after DBM graft placement in the sockets, showing it to be a good alternative as bone graft.

Los injertos de hueso autólogo son considerados el "gold standard" en regeneración ósea debido a sus propiedades osteogénicas; sin embargo, debido a la limitada cantidad de sitios intraorales y la necesidad de resolver las necesidades de los pacientes, es que se requiere una alternativa para el mismo. Dos pacientes masculinos fueron sometidos a una cirugía de implantes en dos etapas con 6 meses de intervalo entre cada una de ellas: la primera consistió en la exodoncia y el posicionamiento del injerto de DBM en el alvéolo; la segunda etapa consistió en el fresado con una trefina de dos milímetros de diámetro interno en el centro del reborde alveolar previamente injertado con DBM y luego se posicionó el implante. Las muestras fueron analizadas bajo técnicas histológicas. Un hueso muy maduro fue observado a los 6 meses de haber injertado el DBM en los alvéolos, demostrando que podría ser una buena alternativa como injerto óseo.

Biochemical, bone and renal patterns in hyperparathyroidism associated with multiple endocrine neoplasia type 1

Primary hyperparathyroidism associated with multiple endocrine neoplasia type I (hyperparathyroidism/multiple endocrine neoplasia type 1) differs in many aspects from sporadic hyperparathyroidism, which is the most frequently occurring form of hyperparathyroidism. Bone mineral density has frequently been studied in sporadic hyperparathyroidism but it has very rarely been examined in cases of hyperparathyroidism/multiple endocrine neoplasia type 1. Cortical bone mineral density in hyperparathyroidism/multiple endocrine neoplasia type 1 cases has only recently been examined, and early, severe and frequent bone mineral losses have been documented at this site. Early bone mineral losses are highly prevalent in the trabecular bone of patients with hyperparathyroidism/multiple endocrine neoplasia type 1. In summary, bone mineral disease in multiple endocrine neoplasia type 1related hyperparathyroidism is an early, frequent and severe disturbance, occurring in both the cortical and trabecular bones. In addition, renal complications secondary to sporadic hyperparathyroidism are often studied, but very little work has been done on this issue in hyperparathyroidism/multiple endocrine neoplasia type 1. It has been recently verified that early, frequent, and severe renal lesions occur in patients with hyperparathyroidism/multiple endocrine neoplasia type 1, which may lead to increased morbidity and mortality. In this article we review the few available studies on bone mineral and renal disturbances in the setting of hyperparathyroidism/multiple endocrine neoplasia type 1. We performed a meta-analysis of the available data on bone mineral and renal disease in cases of multiple endocrine neoplasia type 1-related hyperparathyroidism.

Osteodistrofia hepática / Hepatic osteodystrophy

Osteodistrofia hepática é distúrbio de mineralização óssea associada à doença hepática crônica, sendo a osteoporose, e mais raramente a osteomalácia, sua forma de apresentação clínica. Apesar de pouco diagnosticada e com prevalência de grande variação na literatura, na maioria das vezes, apresenta-se de forma assintomática e, quando não identificada, aumenta consideravelmente o risco de fratura e sequelas permanentes. Seu diagnóstico, portanto, requer alta suspeição e faz-se, na prática clínica, por meio da avaliação da densitometria óssea. De fisiopatogenia multifatorial, envolve fatores genético, ambiental e do próprio estado clínico-nutricional do paciente. Uma atenção maior deve ser despendida a hepatopatas desnutridos, com cirrose hepática avançada, doença colestática crônica e transplantados pelo maior risco de desmineralização óssea. Nesta revisão, será discorrido sobre o metabolismo fisiológico da síntese óssea e a fisiopatologia do distúrbio de mineralização óssea, desde mecanismos fisiopatogênicos na doença hepática crônica, seu diagnóstico e revisão da terapêutica atual empregada.

Hepatic osteodystrophy is a disorder of bone mineralization associated to liver disease, clinically manifested by osteoporosis and more rarely osteomalacia. Although seldomly diagnosed and varying greatly in literature, most of the time, it presents asymptomatically and, when it is not recognized, it enhances considerably the risk of fracture and permanent sequelae. Indeed it requires a high grade of suspicion and it is confirmed by means of bone densitometry evaluation in clinical practice. Presenting with a multifactorial physiopathology, it involves factors, such as genetical, environmental, and patient clinical-nutritional status. A greater attention must be spent on patients with liver disease, especially those malnourished, with advanced cirrhosis, chronic cholestatic disease, and transplanted, because of a higher risk of bone demineralization. In this data, it will be reviewed the bone synthesis metabolism and the physiopathology of bone mineralization disorder ? since fisiopatogenic mechanisms in chronic liver disease, diagnosis and recent therapeutic review employed.

Las adolescentes no pierden densidad mineral ósea en el posparto: estudio comparativo con adultas / Adolescents do not lose bone mineral density postpartum: comparative study with adult women

OBJETIVO: Analizar el patrón de la densidad mineral ósea (DMO), calcio y estradiol séricos, consumo de calcio, índice de masa corporal (IMC) y lactancia en adolescentes y adultas a 15, 90 y 365 días posparto (dpp). MATERIAL Y MÉTODOS: Cohorte prospectivo en 33 adolescentes y 39 adultas con evaluación antropométrica, dietética y ósea en L2-L4 y cuello de fémur; bioquímica con estradiol y calcio séricos. RESULTADOS: Las adolescentes aumentaron de los 15 a los 365 dpp 16 por ciento su DMO de L2-L4, las adultas 3 por ciento. La edad se asoció a este cambio (β=13.779, EE=3.5, p=0.001); la lactancia no se asoció (β=-0.705, EE=0.647, p=0.283). Las adultas presentaron mayor DMO de L2-L4 a 15, 90 y 365 dpp respectivamente (1.151vs 0.978g/cm², 1.195vs1.070g/cm², 1.195vs1.123g/cm², p<0.003). CONCLUSIONES: Las adolescentes incrementaron su DMO tres veces más que las adultas. El cambio en la DMO fue dependiente de la edad e independiente de la práctica de lactancia.

OBJECTIVE: To analyze the pattern of bone mineral density (BMD), serum concentrations of estradiol and calcium levels, dietary calcium, body mass index (BMI), and lactation in adolescents and adult women at 15, 90, and 365 postpartum days (ppd). MATERIAL AND METHODS: A prospective cohort study was conducted of 33 adolescents and 39 adult women. Anthropometric and dietetic evaluations were performed, as well as evaluations of bone mineral density in L2-L4 and femur neck. Estradiol concentrations and calcium serum levels were determined. RESULTS: L2-L4 BMD increased by 16 percent in adolescents, and 3 percent in adult women from day 15 to 365 ppd. While age was associated with this change (β=13.779, EE=3.5, p=0.001), lactation was not (β=-0.705, EE=0.647, p=0.283). The adult women had a higher L2-L4 BMD at 15, 90, and 635 ppd (1.151 vs 0.978g/cm², 1.195 vs 1.070g/cm², 1.195 vs 1.123g/cm², respectively) (p<0.003). CONCLUSIONS: Adolescents' BMD increased three times more than that of adult women. For all women, BMD was dependent of age and independent of lactation.

Bone mineral density in children with steroid-sensitive nephrotic syndrome.

Objective. To observe the influence of prednisolone treatment on bone mineral density (BMD) in children with idiopathic nephrotic syndrome. Methods. Duel-energy X-ray absorptiometry of lumbar spine (L1-L4) was performed on 40 patients (18 first episode and 22 relapsers) of steroid sensitive idiopathic nephrotic syndrome. Results. Patients of first episode and relapsers had comparable values of mean age, weight, height, body mass index, serum calcium, phosphate, spine area, bone mineral content (BMC) and BMD. Relapsing nephrotic syndrome patients received significantly higher mean total cumulative dose of prednisolone in comparison to first episode (p<0.001). The BMD Z-scores were normal in 39 of 40 (97.5%) patients. On regression analysis, it was found that both BMC and BMD did not correlate with cumulative dose of prednisolone, when other co-variants such as age, weight, height and spine area were adjusted. Conclusion. Bone mineral density in steroid sensitive nephrotic syndrome is unaffected by cumulative dose of prednisolone therapy both in first episode as well as relapser group of patients.

Avaliação das metaloproteinases de matriz -2 e -9 em gatos com desmineralização óssea secundária à tirotoxicose induzida / Evaluation of matrix metalloproteinases -2 and -9 in cats under bone demineralization secondary to induced thyrotoxicosis

Observou-se significativo aumento de atividade das formas ativas das metaloproteinases -2 e -9 em gatos com tirotoxicose induzida e desmineralização óssea. As formas pró e intermediária da metaloproteinase -2 elevaram-se com 14 dias de administração hormonal, porém, posteriormente, houve uma tendência de queda. Observou-se correlação negativa entre a forma ativa das metaloproteinases de matriz -2 e -9 e a densidade mineral óssea da extremidade distal do rádio. Os resultados sugerem aumento da degradação da matriz colágena secundária com a elevação dos hormônios tiroidianos.

Significant increase of activity of active forms of matrix metalloproteinases -2 and -9 in cats under induced thyrotoxicosis and bone demineralization was observed. Pro and intermediated forms of matrix metalloproteinases -2 and -9 increased at 14 days of hormonal treatment, followed by decrease tendency. A negative correlation between active forms of matrix metalloproteinases -2 and -9 and bone mineral density of radius distal extremity was also observed. The results suggest an increase of collagen matrix degradation secondary to high levels of thyroid hormones.

Hipercalciuria idiopática y compromiso óseo en niños / Idiopathic hypercalciuria and bone injury in children

Introducción: la Hipercalciuria Idiopática (HI), entidad considerada tradicionalmente benigna y asociada a hematuria o urolitiasis, es uno de los trastornos del metabolismo de calcio y fósforo más frecuente en pediatría. En los últimos años se ha asociado a desmineralización ósea tanto en niños como en adultos. Objetivo: determinar el impacto de la Hipercalciuria Idiopática en el contenido mineral óseo en pacientes pediátricos chilenos. Métodos: estudio de corte transversal; se evaluaron 11 pacientes portadores de Hipercalciuria Idiopática. Se midió calcio en orina de 24 horas y en muestra aislada, calcemia, fosfemia, electrolitos plasmáticos, paratohormona plasmática (PTH) y densitometría ósea (DEXA) de columna lumbar y fémur. Para definir la relación entre la calciuria y las demás variables se utilizó un análisis de correlación simple para variables continuas. Se consideró estadísticamente significativo un p < 0,05. Resultados: se estudiaron 11 pacientes, 6 varones, 8,2 ± 2,7 años. El promedio de calcio en orina 24 h fue 9,1 ± 1,37 mg/kg/día, PTH 40 ± 15 pg/ml y el DEXA columna lumbar (Z score) fue de y -2,1 ± 0,29. El análisis estadístico mostró una correlación negativa entre calciuria de 24 h y densidad mineral ósea de columna lumbar (p < 0,05, r = -0,65), y entre Hipercalciuria vs niveles de PTH (p < 0,05, r = -0,58). Conclusión: la Hipercalciuria Idiopática en pediatría representa un riesgo de compromiso óseo que debe ser considerado al evaluar el manejo de cada paciente.

The preliminary study on the characteristics of mandible and condyle in dentin matrix protein-1 gene knockout mice / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study the characteristics of mandible and condyle in Dmp1 gene knockout mice, and to investigate the role of Dmp1 in the osteogenesis and mineralization of bone and cartilage.</p><p><b>METHODS</b>Dmp1-/-mice were executed at birth, 2 weeks, 2 months, 3 months and 5 months, and the mandible was taken out for physical, radiography, transmission electron microscopic, and histological examination. The difference between Dmp1 knockout mouse (ko) and wild type mouse (wt) in bone development, bone densitometry and histology were compared.</p><p><b>RESULTS</b>There were obvious changes in the mandible and condyle of Dmp1-/-mouse, such as incomplete ossification, low density, decreased volume and condyle cartilage degeneration.</p><p><b>CONCLUSIONS</b>Dmp1 is the key factor in the formation of growth plates and secondary ossification center, and plays an important role in the process of bone and cartilage formation and bone nodule remodeling. Dmp1 may be the candidate gene that controls the development of mandible and cartilage.</p>

Physiotherapy resources on bone mineral density loss prevention in patients with spinal cord injuries / Recursos fisioterapêuticos na prevenção da perda da densidade mineral óssea com lesão medular

Este trabalho é uma revisão bibliográfica sobre os tratamentos fisioterápicos destinados a prevenção, estabilização ou lentificação da perda da densidade mineral óssea em pacientes portadores de lesão medular. Foram encontrados poucos trabalhos que se destinaram aos tratamentos fisioterápicos para desmineralização óssea. Em relação aos tipos de tratamentos encontrados foram: estimulação elétrica funcional, estimulação elétrica funcional com bicicleta ergométrica, ortostatismo e deambulação. Estes tratamentos são bastante questionáveis não tendo um consenso na metodologia, apresentando muitas controvérsias em relação à eficácia dos tratamentos, que serão discutidos no decorrer deste trabalho.

Effects of periodic weight support in a simulated weightless environment in preventing bone demineralisation.

Anti Orthostatic Hypokinetic posture in rats by tail suspension for 15 days (d) simulates the deconditioning effects of weightlessness on the weight bearing bones. The present study evaluates the effects of daily 4 hour (h) weight support (WS) during simulated weightlessness (S-W) in preventing these changes. Adult male albino rats were divided into three groups as (i) Control (CON, n = 12), (ii) Hind limb unweighing by tail suspension for 15 d (HU, n = 18), (iii) HU with daily 4 h WS (4 HRWS, n = 11). After 15 d tibia from all the animals were removed and subsequently dried, ashed and then calcium content of the bones were determined. HU showed reductions in the water content by 35.8%, organic matrix by 12.2% and calcium content by 33.4% of tibia. 4 h WS during S-W resulted in complete prevention of water loss and organic matrix loss and partial prevention of the loss of calcium content. Calcium content of tibia in 4 HRWS remained 15.2% less as compared to CON. These findings indicate that 4 h WS is partially successful in preventing the demineralisation effects of S-W on weight bearing bone tibia.

La osteoporosis como enfermedad pediátrica / Osteoporosis as a pediatric disease

La osteoporosis es una enfermedad que se caracteriza por una pérdida cuantitativa de masa ósea, deterioro microarquitectural, mayor susceptibilidad a fracturas. La adecuada adquisición del pico de masa ósea en la adolescencia minimiza el riesgo del desarrollo de osteoporosis, por lo que se define a la osteoporosis como enfermedad pediátrica. Si durante esta etapa de crecimiento la ingesta es inadecuada en uno o más nutrientes, una posible consecuencia es el deterioro de ese crecimiento, que puede estar afectado cuantitativamente con disminución de la ganancia de peso o talla, pero también cualitativamente, donde la composición del nuevo tejido puede estar alterada. La ingesta adecuada de lácteos a lo largo de toda la vida ha sido descripta como factor fundamental para el desarrollo de una adecuada masa ósea y más específicamente la ingesta de calcio, dado que los productos lácteos podrían favorecer la adquisición de masa ósea a través de otro de sus componentes como la lactosa que aumenta la absorción de calcio por difusión en el ileon. Se describen dos entidades clínicas en diferentes edades de la infancia y adolescencia que cursan con baja masa ósea: la enfermedad ósea metabólica de la prematurez o desmineralización ósea postnatal en lactantes con muy bajo peso al nacer y los trastornos de la conducta alimentaria. Es la infancia y adolescencia, el período de la vida en que se puede ejercer intervención disminuyendo los factores de riesgo de un inadecuado pico de masa ósea, planificando estrategias para la prevención de la osteoporosis (actividad física, ingesta de calcio, exposición solar), por lo que se considera que el riesgo de desarrollar osteoporosis en la vida futura dependerá de la cantidad y resistencia ósea máxima alcanzada por una persona al llegar a la adultez

Fatores de risco da osteoporose: prevenção e detecção através do monitoramento clínico e genético / Osteoporosis risk factors: prevention and detection through clinical and genetic monitoring

A osteoporose é uma doença sistêmica caracterizada pela baixa massa óssea e deterioração da micro arquitetura do tecido ósseo. Consequentemente existe um aumento na fragilidade do osso e suscetibilidade à fratura, que é considerada o efeito clínico mais importante deste processo. Muitos estudos que se utilizam de modelos em gêmeos ou pais e seus descendentes têm confirmado o papel da herança genética no pico de massa óssea, na verdade o maior fator de risco da fratura. Neste artigo de revisão, são enfocados os prováveis genes envolvidos no processo de osteoporose, ressaltando a importância das interações entre gene- gene e gene-ambiente. Concernente à influência isolada do ambiente, são abordados os hábitos relacionados ao estilo de vida, à nutrição e ao tabagismo envolvidos no aparecimento dessa doença. Durante os próximos anos, o conhecimento baseado na genética molecular elucidará o processo osteoporótico. Do mesmo modo, os estudos clínicos se expandirão, visando contribuir para a detecção precoce da doença, permitindo assim a aplicação de medidas preventivas e terapêuticas adequadas.

Osseous demineralization among people more than 50 years

A study on 116 patients more than 50 years in a private clinic in Hue City has shown that 39 patients had symptoms of osseous demineralization in the film of thoraco-liunbal spine. The rat of osseous demineralization increased with age, especially in women. The common complications of the osseous demineralization were long bone fracture and spinal flat.

Severe osteoporosis in childhood anorexia nervosa: Dramatic remineralisation of bone and vertebral body remodelling during recovery

At the age of 12 years a slightly overweight Omani girl started to diet and exercise excessively. This continued for 2 years and her weight fell from 32 to 16 kg accompanied by reddish discoloration of the hair and darkening of the skin due to severe protein calorie malnutrition. Anorexia nervosa [AN] was diagnosed and nasogastric feeding was started. This was complicated by severe transient refeeding oedema. After three weeks of this treatment the patient decided to eat normally. We first saw her six months later, at the age of fourteen and a half years complaining of backache. Examination revealed an intelligent prepubertal girl with a moderate kyphosis weighing 31 kg. Spinal radiographs revealed severe osteopenia and multiple wedge fractures. Her lumbar bone mineral density [BMD] was less than half that of her 12 and 15-year-old normal sisters. Supplemental calcium, multivitamins and low dose oestrogen was added to her normal family After one year, a dramatic improvement was observed; her height and BMD had increased by 10 cm and nearly 40 percent respectively and bone remodelling was observed evidenced by a relative increase in vertebral body height over width. This is the first reported case of AN in an Arabian child Severe osteoporosis is potentially reversible in young people

Hipovitaminosis D en mujeres postmenopáusicas con masa ósea baja en la Región Metropolitana / Vitamin D levels in postmenopausal women with low bone mineral density from Región Metropolitana

Background: Low vitamin D levels are a risk factor for osteoporosis. In the Northern hemisphere, a high frequency of low vitamin D levels has been detected. The correction of this deficit is associated with a lower fracture risk. Aim: To measure serum vitamin D levels in postmenopausal women with low bone mineral density. Material and methods: 25-hydroxyvitamin D levels were measured in 40 postmenopausal women aged 50 to 74 years old, with a spine bone mineral density of less than 2 standard deviation of the values for young individuals. Serum calcium, phosphorus and calcium dietary intake were also measured. Results: Mean serum 25-hydroxyvitamin D levels were 32.2 ñ 12.5 ng/ml. No correlation between vitamin D levels and other measured variables was observed. Using a cutoff value of 15 ng/ml, two women had low 25-hydroxyvitamin D levels. Conclusion: In this sample of postmenopausal women, vitamin D deficiency was infrequent

Bone density in survivors of childhood acute leukemia and malignant lymphomas

This study aimed to assess bone mineral density in survivors of childhood acute leukemia and malignant lymphomas to determine the prevalence of osteoporosis and identify the possible predisposing factors and patients at the greatest risk of reduced bone mineral density. The study included 41 survivors [27 patients had acute lymphoblastic leukemia and 14 patients had malignant lymphomas]. In conclusion, 60.9% of the survivors of childhood leukemias and lymphomas had decreased BMD, osteoporosis being especially severe in 17.1% of these patients. In view of the risk of fractures among patients with osteoporosis, the survivors of childhood malignancy were at an increasing risk of bone fractures later in life irrespective of the underlying cause of osteoporosis, thus the intervention should be considered for prevention and proper management

Tamoxifeno y cáncer de mama / Tamoxifen and breast cancer

El tamoxifeno ha sido un pilar importante en la terapia adyuvante del cáncer mamario. Utilizado inicialmente como un antiestrógeno, el tamoxifeno demostró ser un modulador selectivo de receptores de estrógeno, es decir, ejerce un agonismo estrogénico en ciertos tejidos junto con una acción antagónica estrogénica en otros. Probada su utilidad en la terapia paliativa del cáncer mamario avanzado, investigaciones posteriores indicaron que el tamoxifeno produce efectos benéficos significativos en la terapia adyuvante de los tumores mamarios invasores e in situ como también su uso profiláctico en mujeres con riesgo elevado de desarrollar un cáncer de mama. En está revisión analizamos la utilidad del tamoxifeno en la terapia del cáncer de mama, sus efectos benéficos sobre el sistema óseo y cardiovascular y el efecto adverso en el endometrio