Marcadores bioquímicos propuestos para el estudio de la sarcopenia / Proposed biochemical markers for the study of sarcopenia

La sarcopenia asociada a la edad es una condición clínica caracterizada por una disminución en la fuerza, calidad y cantidad de masa muscular así como también en la función muscular. Un biomarcador se define como una característica que es medible objetivamente y evaluable como indicador de un proceso biológico normal, patológico o respuesta terapéutica a una intervención farmacológica. Los marcadores bioquímicos propuestos para el estudio de la sarcopenia pueden ser categorizados en dos grupos. El primero de ellos evalúa el estatus musculoesquelético; este panel de marcadores está formado por miostatina/folistatina, procolágeno aminoterminal tipo III e índice de sarcopenia. El segundo grupo de marcadores bioquímicos evalúa factores causales, para lo cual se sugiere medir el factor de crecimiento insulino-símil tipo 1 (IGF-1), dehidroepiandrosterona (DHEAS), cortisol, facto-res inflamatorios [proteína C reactiva (PCR), interleuquina 6 (IL-6) y factor de necrosis tu-moral (TNF-a)]. Las recomendaciones realiza-das están basadas en la evidencia científica disponible en la actualidad y la disponibilidad de la metodología apropiada para cada uno de los biomarcadores. (AU)

Sarcopenia is a progressive and generalized skeletal muscle disorder defined by decrease in the strength, quality and quantity of muscle mass as well as in muscle function. A biomarker is defined as a feature objectively measured and evaluated as an indicator of a normal biologic process, a pathogenic process or a pharmacologic response to therapeutic intervention. The biochemical markers proposed for the study of sarcopenia may be classified in two groups. The first group evaluates the musculoskeletal status, made up by myostatin/follistatin, N-terminal Type III Procollagen and the sarcopenia index. The second evaluates causal factors, where the measurement of the following is suggested: hormones insulin-like growth factor-1 (IGF-I), dehydroepiandrosterone sulphate (DHEAS), cortisol, inflammatory factors [C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-a (TNF-a)]. The recommendations made are based on scientific evidence currently available and the appropriate methodology availability for each biomarker. (AU)

Alimentación basada en plantas y su efecto sobre la salud ósea: del mito a la evidencia Plant-based diets and its effects on bone health: from myth to evidence

Resumen Introducción: la alimentación es uno de los factores modificables más importantes que participa en la salud ósea. Contribuye a ésta, una adecuada ingesta de calcio, vitamina D y proteínas, como así también otros nutrientes. A la alimentación basada en plantas (ABP) se le ha atribuido importantes beneficios para la salud en general, pero mal planificada podría tener efectos deletéreos sobre la salud ósea. Materiales y método: revisión narrativa con búsqueda en el sistema digital de recopilación de información biomédica PubMed cuyo objetivo fue analizar la evidencia científica disponible en la actualidad sobre el efecto de la ABP sobre la salud ósea. Resultados: dentro de los patrones de consumo de la ABP, los veganos que exhiben un consumo de calcio inferior a 525 mg/día presentan mayor riesgo de fractura por fragilidad ósea [incidencia de fractura: 1.37 (IC95%: 1,07; 1,74)]. En cambio, el papel de la hiperhomocisteinemia (HHcy) secundaria al déficit de vitamina B12 y riesgo de fractura continúa siendo controvertido en esta población. Si bien, in vitro la HHcy puede incrementar la actividad de los osteoclastos, en estudios clínicos no se observaron diferencias estadísticamente significativas en los niveles de crosslaps sérico (marcador de resorción ósea) en los consumidores de ABP (vegetarianos) comparados con los omnívoros. Conclusión: una ABP bien planificada, óptima y adecuada, que cubra los requerimientos diarios de calcio, vitamina D, vitamina B12 y proteínas aportará importantes beneficios para la salud general sin afectar la salud ósea en particular, aunque se requiere de futuros estudios para una mejor comprensión de su efecto sobre aspectos específicos del sistema musculo esquelético.

Abstract Introduction: diet is one of the most significant and modifiable factors involved in bone health, as an appropriate intake of calcium, vitamin D and proteins, as well as other nutrients, contributes to this. Significant overall health benefits have been attributed to plant-based diets (PBD); however, poorly planned PBD could have detrimental effects on bone health. Materials and Method: a narrative review through a search in the digital biomedical data collection system PubMed whose objective was to analyze currently available scientific evidence about the effects of PBD on bone health. Results: within the PBD intake patterns, vegans exhibiting calcium intakes below 525mg/day are at a higher risk of fracture due to bone fragility [incidence of fracture: 1.37 (95% CI: 1.07; 1.74)]. In contrast, the role of hyperhomocysteinemia (HHcy) secondary to vitamin B12 deficiency and fracture risk remains controversial in this population. While in vitro HHcy osteoclast activity may increase, in clinical studies no statistically significant differences in serum crosslaps levels (bone resorption marker) were observed in PBD consumers (vegetarians) when compared to omnivores. Conclusion: a well-planned, optimal and adequate PBD, covering daily calcium, vitamin D, vitamin B12 and proteins requirements, will provide significant benefits to the overall health condition without affecting bone health in particular, although future studies are required in order to better understand its effects on specific aspects of the musculoskeletal system.

Is periostin useful as a biomarker for fibrous dysplasia? / ¿Es útil periostina como biomarcador de displasia fibrosa?

Fibrous dysplasia (FD) is an infrequent non-hereditary bone disease caused by a somatic mutation of the GNAS gene. Periostin is a novel marker that increases during tissue healing and fibrous or inflammatory diseases. We conducted an exploratory case-control study to evaluate sensitivity of periostin as a biomarker of FD. The study comprised 15 patients with FD, and healthy age- and sex-matched subjects (controls). Serum periostin levels were assessed and comparisons were established between FD patients and controls, and between patients with the monostotic and the polyostotic form of FD. No statistically significant differences in serum periostin levels were observed between the cohort of FD patients studied here and the control group (FD: 51.1±10ng/ml vs. control: 44.2±15ng/ml; p=0.15), or between the clinical forms of FD (polyostotic: 51.8±9.1ng/ml vs. monostotic: 49.6±13 ng/ml; p=0.66). A sub-analysis performed to compare serum levels of periostin in FD patients with and without a history of fractures showed no statistically significant differences [fracture patients (n=4): 41.2±17ng/ml vs. non-fracture patients (n=11): 49.9±11 ng/ml; p=0.47].Lastly, sensitivity of periostin as a biomarker of FD was analyzed, and was found to have low sensitivity to estimate disease activity [ROC curve; cut-off points: 39.625(0.867-0.467)]. To conclude, in the cohort of FD patients studied here, periostin serum levels did not differ significantly from those of the control group or between the two forms of the disease, and showed low sensitivity as a biomarker of the disease. (AU)

La displasia fibrosa (DF) es una enfermedad infrecuente del hueso, no hereditaria producida por una mutación somática del gen GNAS. Periostina (Postn) es un novedoso marcador, cuyos niveles séricos se encuentran elevados en los procesos de reparación tisular, enfermedades fibrosas o inflamatorias. Llevamos a cabo un estudio exploratorio caso-control para evaluar la sensibilidad de Postn como biomarcador de DF. Se incluyeron en el estudio 15 pacientes con DF apareados por edad y género con sujetos sanos (controles) en los cuales se evaluó los niveles séricos de Postn en pacientes con DF y controles y según forma de presentación clínica. No observamos diferencias estadísticamente significativas en los niveles séricos de Postn y el grupo control (DF: 51.1±10ng/ml vs. control: 44.2±15ng/ml; p=0.15) como así tampoco por forma clínica de DF (poliostótica: 51.8±9.1ng/ml vs. monos-tótica: 49.6±13 ng/ml; p=0.66). Posteriormente realizamos un sub-análisis para evaluar los niveles séricos de Postn en los pacientes con DF y antecedentes de fracturas no observan-do diferencias estadísticamente significativas [fracturados (n=4): 41.2±17ng/ml vs. no frac-turados (n=11): 49.9±11 ng/ml; p=0.47]. Por último analizamos la sensibilidad Postn como biomarcador de DF, mostrando este poseer escasa sensibilidad para estimar actividad de la enfermedad [curva ROC; puntos de corte: 39.625 (0.867-0.467)]. En conclusión, los ni-veles séricos de Postn en nuestra cohorte de pacientes con DF no mostraron diferencias estadísticamente significativas comparadas con el grupo control o por forma clínica de presentación, mostrando una baja sensibilidad como biomarcador de enfermedad. (AU)

Osteoporosis de la posmenopausia: ante el desafío de elegir la estrategia terapéutica / Postmenopausal osteoporosis: facing the challenge of choosing a therapeutic strategy

La osteoporosis de la posmenopausia es una enfermedad crónica y progresiva asociada con un bajo pico de masa ósea o una rápida y persistente pérdida de masa ósea como con-secuencia del déficit de estrógenos endógenos y del envejecimiento. A pesar de que en la actualidad la oferta de medicamentos para su tratamiento en distintas etapas de la vida es muy importante, sigue siendo una enfermedad subdiagnosticada y subtratada a nivel global. La edad, las comorbilidades existentes, los tratamientos concomitantes, el riesgo de caídas, y los antecedentes familiares o personales de fracturas recientes o pasadas tanto como la densidad mineral ósea son factores que deben ser considerados en la evaluación de cada paciente para determinar el grado de riesgo de fractura En aquellos considerados con alto riesgo o riesgo inminente de fractura se recomienda iniciar un tratamiento con algún agente anabólico seguido por un anticatabólico para lograr una rápida reducción del riesgo de fractura. Por último, una adecuada adherencia en el tiempo al tratamiento es clave para alcanzar la mayor eficacia terapéutica dirigida a la reducción de la ocurrencia de fracturas por fragilidad ósea. (AU)

Postmenopausal osteoporosis is a chronic and progressive disease associated with low peak bone mass or a fast and persistent loss of bone mass as a consequence of endogenous estrogen deficiency and aging, and it is an underdiagnosed and undertreated disease worldwide. At present, there is a wide range of drugs available for the treatment of postmenopausal osteoporosis, with appropriate treatments for each phase of this stage of a woman's life. All factors that may increase the risk of bone fragility fracture should be considered at the time of patient assessment. These include age, existing comorbidities, concomitant treatments, risk of falling, family history of fractures or recent or past personal history of fractures, and the results of bone mineral density assessment. In those patients at high risk or imminent risk of fracture, it is recommended to start treatment with an anabolic agent followed by an anticatabolic agent, in order to achieve an immediate reduction of fracture risk. Finally, an adequate adherence to treatment over time will allow achieving the greatest effectiveness of the proposed therapy, which is the reduction of bone fragility fracture events. (AU)

Nuevos avances en el conocimiento de la historia natural de la displasia fibrosa / News advances in the knowledge of natural history of the fibrous dysplasia

La displasia fibrosa (DF) es una enfermedad infrecuente del hueso, no hereditaria, producida por una mutación activadora del gen GNAS, responsable de codificar la unidad a-estimuladora de la proteína G (Gsa). La presentación clínica de la enfermedad es muy variada, pues adopta desde formas asintomáticas hasta otras marcadamente sintomáticas. En los últimos años, el análisis exhaustivo de bases de datos de pacientes con DF ha permitido conocer más sobre su historia natural. En este artículo se revisa la información actualmente disponible sobre algunos aspectos que ayudarán al mejor enfoque clínico del paciente, como son: la utilidad clínica de los marcadores óseos, los factores pronósticos para el desarrollo de fracturas, la DF como condición predisponente para el desarrollo de tumores específicos, nuevas perspectivas sobre la fisiopatología del dolor óseo y nuevas estrategias terapéuticas. Un mayor conocimiento sobre la historia natural de esta enfermedad finalmente redundará en la mejor calidad de vida de los pacientes con DF. (AU)

Fibrous dysplasia (FD) is an infrequent, non-hereditary bone disease caused by a somatic mutation of the GNAS gene, responsible for encoding the a-subunit of the G-protein (Gsa). The clinical presentation of the disease varies greatly, with some patients being asymptomatic and others markedly symptomatic. The exhaustive analysis of the database from patients with FD has allowed to learn more about the natural history of this disease. This article reviews the current information available on the clinical utility of bone markers, the prognostic factors for the occurrence of fractures, the evidence supporting as a predisposing condition for the development of specific tumors, new perspectives on the pathophysiology of bone pain, and emerging therapeutic strategies. A greater understanding of the natural history of this disease will allow to make better medical decisions, which will ultimately contribute to improve FD patients' quality of life. (AU)

Distrofia ósea esclerosante mixta / Mixed-sclerosing-bone-dystrophy

El término "distrofia ósea esclerosante mixta" describe la combinación de las características radiológicas correspondientes a melorreostosis, osteopoiquilosis y osteopatía estriada, como entidades individuales, que ocurren en un mismo paciente. El objetivo de esta comunicación es presentar el caso clínico de una paciente con diagnóstico de distrofia ósea esclerosante mixta y, a partir de este caso, realizar una revisión sobre el tema. (AU)

The term "mixed-sclerosing-bone-dystrophy" describes the combination of the radiological characteristics corresponding to melorheostosis, osteopoikilosis and osteopathia striata, as individual conditions, ocurring in the same patient. The aim of this communication is to present the clinical case of a patient diagnosed with mixed-sclerosing-bone-dystrophy and, based on this case, to undertake a review of this condition. (AU)

Estudio comparativo de la absorción neta de calcio de dos formulaciones distintas de carbonato de calcio en mujeres posmenopáusicas / Comparative study of net calcium absorption of two different pharma¬ceutical formulations of calcium carbonate in posmenopausal women

La suplementación con calcio reduciría, sola o asociada a otra medicación para osteoporosis, la pérdida de masa ósea y el riesgo de fracturas. Sin embargo, su tasa de adherencia es baja debido a la poca tolerancia. Objetivo: comparar la tasa de absorción neta de calcio entre dos formulaciones distintas de carbonato de calcio (500 mg): comprimidos vs. mousse. Material y métodos: 11 pruebas fueron realizadas en mujeres posmenopáusicas de 58,9±3 años. El diseño fue exploratorio abierto, aleatorizado, prospectivo cruzado de fase 4. Intervención: las participantes fueron aleatorizadas en dos grupos para recibir las dos formulaciones previa suplementación con vitamina D3. La tasa de absorción neta de calcio fue estudiada por la prueba de inhibición de hormona paratiroidea (PTH). Se obtuvieron muestras de sangre: basal y en la 1a, 2a y 3a hora posadministración del calcio asignado, y de orina de 2 horas basal y al final de la prueba. Determinaciones bioquímicas: calcio, fósforo, albúmina, 25-hidroxivitamina D y hormona paratiroidea intacta y calciuria. Análisis estadístico: método de los trapecios para calcular el área bajo la curva (AUC) de la concentración de calcio en el tiempo (R Development Core Team (2008). http://www.Rp-project.org) y Anova con dos términos de error para evaluar el efecto secuencia, período y formulación. Resultados: la mayor inhibición de PTH se observó a dos horas de la toma de ambas formulaciones (comprimidos -39,2% vs. mousse -38,0%; p=ns), con similar AUC0-3 h (comprimidos 3,35; IC 95%: 3,32; 3,37 vs. mousse 3,36; IC 95%: 3,33; 3,38). Cuando analizamos tolerancia y preferencias no se observaron diferencias estadísticamente significativas entre ambas formulaciones. Conclusión: el carbonato de calcio en mousse mostró similar tasa de absorción intestinal, preferencia y tolerancia gastrointestinal que en comprimido. (AU)

Calcium supplementation, administered alone or in combination with a specific medication for osteoporosis, would reduce bone mass loss and fracture risk in postmenopausal women. However, the adherence rate to calcium supplements is low, mainly due to low tolerance. Objective: comparisson of net calcium absorption rate between two different pharmaceutical formulations of calcium carbonate (PFCa) in postmenopausal women. Materials and Methods: 11 tests were performed in postmenopausal women aged 58.9±3 yrs. Design: Comparative, randomized, prospective, open-label exploratory crossover study of calcium mousse versus calcium pills. Intervention: Participants were randomized in 2 groups to receive the 2 different PFCa (500mg): pills vs. mousse, with previous vitamin D3 supplementation. The parathyroid hormone (PTH) inhibition test and the area-under-thecurve (AUC) of calcium were analyzed. Blood samples were taken at baseline and 1, 2 and 3 hrs after intake of the assigned PFCa. Urine samples (2hs) were obtained at -baseline, after 2hs of PFCa intake and at the end of the test. Biochemical Determinations: Serum: calcium, phosphorus, albumin, 25-hydroxyvitamin D, and intact PTH. In urine: calcium. Statistical Analysis: The trapezoid rule was applied to assess AUC in time (R Development Core Team (2008). http://www.Rp-project.org). An ANOVA model with 2 error terms was used to assess the effect of sequence, period, and formulation. Results: The highest inhibition PTH rates were observed after 2 hrs of PFCa (pills -39.2% vs. mousse -38.0%; p=ns). The AUC0-3hrs for both PFCa was similar (pills 3.35; 95%CI: 3.32; 3.37 vs. mousse 3.36; 95%CI: 3.33; 3.38). No statistically significant differences were observed when we analyze tolerance and predilection. Conclusion: The calcium carbonate in mousse showed an adequate rate of intestinal absorption, similarly predilection and gastrointestinal tolerance than the pill presentation. (AU)

Vitamin D levels and their impact on mineral metabolism in HIV infected patients: an exploratory study.

Vitamin D has immunomodulating properties. The nuclear receptor for vitamin D is expressed in several immune cells, which convert 25-hydroxyvitamin D (25OHD) to the active form 1,25 hydroxyvitamin D [1,25(OH)2 D]. Under conditions of infection, 1,25(OH)2 D promotes production of cathelicidin (an antimicrobial peptide) in monocytes and activated macrophages. In vitro studies have shown the ability of cathelicidin to inhibit replication of human immunodeficiency virus (HIV-1) in T CD4 lymphocytes and macrophages. OBJECTIVE: To evaluate vitamin D levels and their impact on mineral metabolism in HIV infected patients. MATERIALS AND METHODS: Seventy-four clinical records of HIV/AIDS patients seen at the outpatients clinic were reviewed. The following data were collected: age, sex, time since diagnosis of HIV, HIV-1 viral load, CD4 counts (absolute value and percentage), and mineral metabolism determinations: 25OHD, intact parathormone (iPTH); serum calcium (sCa); serum phosphorus (sP) and serum crosslaps (sCTX). Vitamin D levels were stratified as follows: optimal: ≥30ng/ml; insufficient: 21-29ng/ml; moderately deficient: 20≥ -25OHD- >10 ng/ml and severely deficient ≤10 ng/ml. RESULTS: Fifty-five clinical records were included; 82% of patients had 25OHD levels below 30ng/ml (insufficient: 23.6%, moderately deficient: 36.4%; and severely deficient: 21.8%). A significantly higher serum PTH levels in the moderately and severely deficient groups than in the optimal and insufficient groups was observed (p<0.05 and p<0.03 respectively). A weak negative correlation was observed between serum 25OHD and PTH levels (r=-0.268; p<0.004). CONCLUSION: Sub-optimal vitamin D levels are frequently observed in HIV/AIDS patients on antiretroviral therapy (ART). Systematic assessment of mineral metabolism is considered necessary in HIV/AIDS positive patients.

Effect of Time of Administration of Teriparatide on Bone Mineral Density in Glucocorticoid-Induced Osteoporosis.

Teriparatide (TPTD) (recombinant DNA origin human parathormone [1-34]) is approved for the treatment of glucocorticoid-induced osteoporosis (GIO). There are reports of factors that affect the response to TPTD in GIO treatment. This work describes the case of a 71-yr-old woman diagnosed with lupus nephropathy treated with 40 mg/d of meprednisone, and who suffered multiple vertebral fractures. Despite treatment with a single 5 mg dose of zoledronic acid, the patient continued to have vertebral fractures. Treatment with 20 µg/d of subcutaneous TPTD (PTH1-34, Forteo; Eli Lilly Co., Indianapolis, IN) was initiated. Nine months after the onset of treatment, bone mineral density (BMD) assessment showed a 5% decrease in lumbar spine BMD. Factors potentially affecting the results were analyzed. The patient reported injecting TPTD at night and was instructed to inject TPTD in the morning before breakfast. After changing the time of TPTD administration and 22 mo after initiating treatment, BMD assessment was repeated and showed an 18% increase at the lumbar spine and no new vertebral fractures. The time of TPTD administration might affect the response to TPTD in GIO treatment.

Teriparatide for the rapid resolution of delayed healing of atypical fractures associated with long-term bisphosphonate use.

Bisphosphonates (BPs) are the most widely used drugs to treat osteoporosis. However, recent reports associated to long-term BPs use with atypical low-impact fractures and prodromal pain. It is estimated that 26% of the cases of atypical fractures associated with the long-term use of BPs show delayed healing or nonunion. Teriparatide [PTH1-34] (TPTD) is an anabolic drug shown to be effective in stimulating bone formation. The aim was to describe the course of a right diaphyseal femoral fracture sustained by a patient on long-term BPs treatment. A 57-year-old postmenopausal Caucasian female presented with delayed healing of a right femoral diaphyseal fracture 10 months after the fracture, despite having received orthopedic treatment. The fracture was preceded by progressive, severe, and bilateral thigh pain. Her medical history included osteopenia that was treated with alendronate over 7 years. On presentation at our clinic, the patient ambulated with the aid of a walking cane. The diagnosis was an atypical right femoral fracture associated with long-term alendronate use. The levels of the following parameters were measured: mineral metabolism laboratory: intact parathormone, 40 ng/mL (reference values (rv): 10-65 ng/mL); 25-hydroxyvitamin D, 40 ng/mL (rv: >30 ng/mL); serum Crosslaps, 318 ng/mL (rv: 80-590 ng/mL); and bone-specific alkaline phosphatase, 76UI/L (rv: 31-95UI/L)]. Magnetic resonance imaging of the left femur was performed, which revealed a diaphyseal stress fracture. She was prescribed 20 µg/day of subcutaneous (s.c.) TPTD (PTH1-34, Forteo; Eli Lilly Co., Indianapolis, IN, United States). A computed tomography scan performed 3 months later showed that the fracture had healed; the patient was able to resume her usual activities. Twenty micrograms per day of s.c. TPD accelerated the healing of the atypical fracture associated with long-term alendronate therapy, allowing a fast recovery of ambulation and quality of life.

Osteosarcopenia: un factor de riesgo para fracturas osteoporoticas / Osteosarcopenia: a risk factor for osteoporotic fractures / Osteo-sarcopenia: um fator de risco para fraturas osteoporóticas

La sarcopenia asociada a la edad es una condicion caracterizada por una disminucion de la masa y fuerza muscular de causa multifactorial. El hueso y el musculo son dos tejidos que se encuentran interrelacionados entre si. Las fuerzas mecanicas aplicadas sobre el hueso son aquellas originadas por la contraccion muscular, lo cual condiciona las propiedades del hueso como masa, tamano, forma y arquitectura. Por la tanto, la disminucion de la masa y fuerza muscular conduciran a una disminucion de la cantidad y calidad osea. De esta manera, la sarcopenia es una condicion que en adultos mayores incrementa el riesgo de caidas y fracturas por fragilidad osea, por lo que se propone el termino de osteosarcopenia para identificar aquellos adultos mayores con mayor riesgo de fracturas por fragilidad osea. En la actualidad, el desarrollo de un consenso sobre los criterios diagnosticos de osteosarcopenia son demandados por la comunidad medica ya que estos permitirian identificar a los pacientes con mayor riesgo de desarrollar fracturas osteoporoticas, realizar intervenciones terapeuticas adecuadas y mejorar la calidad de vida de los adultos mayores.

Age-related sarcopenia is a condition which typically shows a decline in muscle mass and strength due to multifactorial causes. Bones and muscles are two interrelated tissues. The mechanical forces applied on bones are those derived from muscle contraction, conditioning bone properties, such as mass, size, shape and architecture. Therefore, the decline of muscle mass and strength would lead to a decrease in bone quality and quantity resulting in bone frailty. For this reason, sarcopenia is a condition that increases the risk of suffering falls and fractures in older adults. Currently, osteosarcopenia is the term used to identify those older adults with a greater risk of fractures due to bone frailty; however, a consensus of the medical community is needed for developing diagnostic criteria which makes it possible to identify patients with a high risk of developing osteoporotic fractures, to perform adequate therapeutic interventions and to improve the quality of life of older adults.

A sarcopenia associada à idade é uma condição caracterizada por uma diminuição da massa e da força muscular derivada de uma série de causas. O osso e o músculo são dois tecidos que se encontram inter-relacionados entre si. As forças mecânicas aplicadas sobre o osso são aquelas originadas pela contração muscular, que condiciona as propriedades do osso, tais como a massa, o tamanho, a forma e a arquitetura. Portanto, a diminuição da massa e da força muscular conduzirão à uma diminuição da quantidade e da qualidade ósseas. Desta maneira, a sarcopenia é uma condição que em adultos idosos incrementa o risco de quedas e fraturas em razão da fragilidade óssea, razão pela qual se propõe o termo osteo-sarcopenia para identificar a aqueles idosos com maior risco de fraturas por fragilidade óssea. Na atualidade, o desenvolvimento de um consenso sobre os critérios diagnósticos da osteo-sarcopenia é demanda da comunidade médica, na medida em que permitiria identificar os pacientes com maior risco de desenvolver fraturas osteoporóticas, realizar intervenções terapêuticas adequadas e melhorar a qualidade de vida dos idosos.

Periostina: su expresión en los procesos de reparación ósea / Periostin expression in bone repair processes: sua expressão nos processos de reparação Óssea / Periostina

La periostina es una proteína no colágena expresada preferentemente en el periostio, que tiene un papel importante en la formación ósea durante la embriogénesis pero también durante la reparación de lesiones óseas o enfermedades metabólicas óseas. En el primer caso, en los procesos de consolidación de fractura, en modelos de animales de experimentación, se observó un incremento de la expresión de periostina inmediatamente posterior a la fractura, lo que sugirió que ésta tendría un papel relevante en la formación del callo óseo periostial durante los estadíos tempranos del proceso de consolidación de fractura. En enfermedades óseas benignas, como la displasia fibrosa, se observó un incremento de la expresión de periostina en el componente fibroso de la lesión, y se la propone como un marcador inmunohistoquímico en los estudios anatomopatológicos. La periostina es un factor soluble que puede ser detectado en sangre periférica. En los últimos años se desarrollaron numerosos inmunoensayos para su medición pero con la limitante que estos miden todas las isoformas circulantes de periostina con lo que se resta especificidad ósea. El desarrollo de nuevos inmunoensayos con mayor especificidad y sensibilidad a los actuales es de crucial importancia para investigar el potencial que tiene la periostina como biomarcador del metabolismo del periostio, calidad y resistencia ósea.

Periostin is a non-collagenous protein expressed mainly in the periosteum, which has an important role during embryonic bone formation but also when repairing bone lesions or metabolic bone diseases. In the first case, when healing fractures and during experimental animal models, a periostin increased expression has been observed immediately after fractures. These findings suggest that periostin may play an important role in periosteal callus formation during the early stage of fracture healing. In benign bone diseases, like fibrous dysplasia, the periostin over-expression was observed in the fibrous component lesion. So, this protein could be detected by immune histochemical technique in histopathology studies. Periostin is a soluble factor, which can be detected in peripheral blood. In recent years, several immunoassays have been developed, though the main limiting factor is the detection of all molecule circulating isoforms, without providing bone specificity. Development of new immunoassays with greater specificity and sensibility than the current ones is crucial to the research concerning the potential of periostin as a biomarker of periosteal metabolism, bone quality and resistance.

Periostina é uma proteína não-colágena que se expressa principalmente no periósteo, o que tem um papel importante na formação óssea durante a embriogênese, mas também durante a reparação de lesões ósseas ou doenças metabólicas ósseas. No primeiro caso, nos processos de consolidação de fratura, em modelos de animais de experimentação, observou-se um aumento na expressão de periostina imediatamente após a fratura, sugerindo que ela teria um papel relevante na formação do calo ósseo periosteal durante as fases precoces do processo de consolidação de fratura. Em doenças ósseas benignas, tais como displasia fibrosa, foi observado um aumento da expressão de periostina no componente fibroso da lesão, propondo-se como um marcador imuno-histoquímico nos estudos anatomo-patológicos. Periostina é um fator solúvel, ele pode ser detectado em sangue periférico tendo sido desenvolvido nos últimos anos inúmeros imunoensaios para sua medição, porém com a limitação de eles medirem todas as isoformas circulantes de periostina tirando-lhe especificidade óssea. Desenvolver novos imunoensaios com maior especificidade e sensibilidade que os atuais é de extrema importância para investigar o potencial que tem a periostina como biomarcador do metabolismo do periósteo, qualidade e ressistência óssea.

Prevalence of Osteoporosis in Women in Buenos Aires Based on Bone Mineral Density at the Lumbar Spine and Femur.

The aim of the study was to report values for osteoporosis (OP) prevalence in Buenos Aires. Bone mineral density (BMD) at different skeletal sites was measured from November 2012 to July 2014. Participants were recruited through a newspaper advertisement inviting women at least 50 yr of age to receive free BMD measurement. After signing an informed consent form, 5448 women living in Buenos Aires and surrounding districts were studied. Lumbar spine (L1-L4), femur neck, and total hip BMDs were measured (Lunar Prodigy, software version 12.3 GE, Madison, WI, USA). OP was defined as a T-score ≤-2.5 at the lumbar spine or the femoral neck. Results showed that 1021 out of 5448 studied subjects (18.7%) had OP at the lumbar spine or the femoral neck. Comparison of age of the population sample with reference data for the general population showed a moderate (+0.6%) increase in prevalence. Prevalence of OP was low, up to the age of 70 yr when based on femoral neck BMD only. Conversely, the prevalence of OP at the lumbar spine, which was reportedly high in women up to the age of 70 yr, tended to level off over that age. The results of the total femur only added a slight (+0.7%) nonsignificant increase to the OP prevalence. A total 346,500 out of 1,853,000 women aged 50+ yr in Buenos Aires had OP at the lumbar spine or femoral neck, whereas only 163,500 had OP at the upper femur, reducing the number by 53%. The present study assessed OP prevalence in the most densely populated urban area in Argentina. The results are similar to those reported for Caucasian populations in the United States and Canada. As measurement of only the BMD of femoral neck overlooks the diagnosis in half of the women, future studies should include measurement of the lumbar spine in combination with the femoral neck for a more accurate estimation of OP prevalence.

Prevalencia de osteoporosis: discrepancia de acuerdo a las áreas esqueléticas de medición / Prevalence of osteoporosis: discrepancy according to the skeletal areas of evaluation

Existe discrepancia en la elección de las áreas esqueléticas a evaluar para determinar la prevalencia de osteoporosis (OP). La International Society for Clinical Densitometry sugiere evaluar la columna lumbar (CL) y el fémur proximal (FT), mientras que la International Osteoporosis Foundation (IOF) sugiere medir solo el cuello femoral (CF). La estimación de la prevalencia de OP evaluada solo por CF en mujeres mayores de 50 años de Buenos Aires mostró un sub-diagnóstico del 53%. Objetivo: analizar la discrepancia en la prevalencia de OP, según el área esquelética evaluada por DXA, en los estudios internacionales disponibles. Materiales y Métodos: Se incluyeron los trabajos publicados en la literatura internacional, en idioma inglés que contenían: 1. Medición simultánea de CL y CF. 2. Análisis por décadas a partir de los 50 años y hasta por lo menos la década 70-79. 3. Diagnóstico densitométrico de osteoporosis con el criterio de la OMS: T-score ≤-2.5. Resultados: fueron incluidos doce estudios. La evaluación de estos estudios arrojó un sub-diagnóstico global del 52 % si la prevalencia de OP fuera estimada solo por la densidad mineral ósea (DMO) de CF. Cuando analizamos por décadas la sub-estimación fue del 75% en la 6a década, 58% en la 7a década y del 22% en 8a década, mostrando claramente que el subdiagnóstico disminuye a medida que aumenta la edad y desaparece después de los 80 años. Conclusión: Estos resultados señalan que la prevalencia de OP debe ser determinada a través de la evaluación de la DMO de ambas áreas esqueléticas: CL y CF. (AU)

There is discrepancy in the election of skeletal areas to be measured to determine the prevalence of osteoporosis.The International Society for Clinical Densitometry suggests evaluating the lumbar spine and proximal femur, while the International Osteoporosis Foundation (IOF) suggests measuring only the femoral neck.The estimate of the prevalence of osteoporosis (OP) evaluated only for femoral neck (FN) in women over 50 years of Buenos Aires showed underdiagnosis of 53%. Objective: To analyze the discrepancy on the prevalence of OP, according to the skeletal area evaluated by DXA, in international studies. Material and Methods: We included the works published in the international English literature that contained: 1- Simultaneous measurement of lumbar spine (LS) and femoral neck (FN). 2- Analysis for decades from 50 years and up to at least the decade 70-79. 3- Densitometric diagnosis of osteoporosis according to WHO: T-score ≤-2.5. Results: Twelve studies were included. The evaluation of these studies showed an overall underdiagnosis of 52% if the prevalence of OP was estimated only for bone mineral density of the femoral neck.When we analyzed for decades the underestimation was 75% in the sixth decade, 58% in the seventh and 22% in the eighth decade, clearly showing that the underdiagnosis decreases as age increases and disappears after 80 years. Conclusion: This over-all review of 12 studies indicates that lumbar spine as well as femoral neck should be assessed by DXA to determine the prevalence of osteoporosis. (AU)

Regression of an ossifying fibroma of the tibia after a fracture involving the lesion. Possible role of the periostina.

Ossifying fibroma (OF) of the long bones is a benign fibro-osseous lesion typically seen in the first decade of life. OF usually progresses until the age of 10 years, but is occasionally found to regress spontaneously after puberty. The pathogenesis of OF is unknown; however, it has been suggested that the basic defect is in the periosteum. We present the radiological course of an OF of the tibia in a young patient, showing a rapid almost complete regression of the lesion after a tibial fracture at the lesion site. We postulate that the fracture-induced activation of the periosteum in a growing skeleton was fundamental to the regression of the lesion.

[Exploratory study of dietary intake and prevalence of vitamin D deficiency in women ≥ 65 years old living in their family home or in public homes of Buenos Aires city, Argentina]. / Estudio exploratorio de la ingesta y prevalencia de deficiencia de vitamina D en mujeres ≥ de 65 años que viven en su hogar familiar o en residencias para autoválidos de la ciudad de Buenos Aires, Argentina.

UNLABELLED: Both nutritional status and social-environmental factors influence elderly's health and quality of life. An inadequate intake of protein, calcium and vitamin D affects bone health. OBJECTIVES: 1) To assess energy, protein, calcium and vitamin D intake in women ≥65 year of age (y); 2) To assess the contribution of residence place: family home (FH) o Public Homes (PH); 3) To evaluate the relationship between the dietary intake and the biochemical parameters. POPULATIONS: Forty-four ambulatory and clinically healthy women with (X ± SD) 75 ± 7 y and a body mass index 28 ± 4 kg/m². METHODS: 1) Food frequency, sunlight exposure and socioeconomic status questionnaires; 2) Laboratory: Serum 25 hydroxyvitamin D (25OHD), crosslaps (CTX), calcium (sCa), phosphate, bone alkaline phosphatase and urine calcium/creatinine ratio (uCa/ UCr) in 2-hour urine samples. RESULTS: The total group showed intakes lower than the dietary reference intake, except regarding protein intake, with higher deficit in the PH group. The 88% showed vitamin D deficit (25OHD < 20 ng/ml). A positive correlation between 25OHD and vitamin D intake (r = 0.46; p < 0.007) and a negative correlation between 25OHD and CTX (r = -0.51; p < 0.03) in those subjects with 25OHD < 15 ng/ml. The levels of 25OHD, sCa and uCa/uCr were higher in the HF than in PH. CONCLUSION: Both the vitamin D deficiency and the inadequate intake of calcium and vitamin D might have deleterious bone health consequences. Nutritional educational programmes and vitamin D supplementation would be required for this specific age group, especially for high risk groups such as PH.

El estado nutricional y factores socioambientales influyen sobre la salud y calidad de vida del adulto mayor. Ingestas inadecuadas de proteínas, calcio y vitamina D afectan la salud ósea. Objetivos: 1) Evaluar el aporte de energía, proteínas, calcio y vitamina D en mujeres ≥65 años; 2) Analizar según el lugar de residencia: hogar familiar (HF) o residencias semicautivas (RSC); 3) Evaluar la relación entre ingesta y parámetros bioquímicos. Población: 44 mujeres ambulatorias y clínicamente sanas de (X ± DE) 75 ± 7 años, índice de masa corporal 28 ± 4 kg/m2. Métodos: 1) Cuestionarios de frecuencia de consumo de alimentos, exposición solar y nivel socioeconómico. 2) Laboratorio: En suero: 25-hidroxivitamina D (25OHD), crosslaps (CTX), calcio (Cas), fósforo y fosfatasa alcalina ósea e Índice calcio/creatinina (Cau/Cru) en orina de 2 h. Resultados: El grupo total presentó ingestas inferiores a las recomendadas excepto en proteínas, con déficit mayor en RSC. El 88 % presentó deficiencia de vitamina D (25OHD < 20 ng/ml). Se halló correlación positiva entre 25OHD e ingesta de vitamina D (r = 0,46; p < 0,007) y correlación negativa entre 25OHD y CTX en aquellas con niveles < 15 ng/ml (r = -0,51; p < 0,03). Los niveles de 25OHD, Cas y Cau/Cru fueron mayores en HF que RSC. Conclusión: La alta prevalencia de déficit de vitamina D, ingesta inadecuada de calcio y vitamina D en mujeres añosas constituye un factor de riesgo para la salud ósea. Se requieren programas de educación alimentaria y eventual suplementación con vitamina D enfatizados en grupos de mayor riesgo como RSC.