RESUMO

Bone mass and strength achieved at the end of the growth period, simply designated as 'Peak Bone Mass (PBM)', plays an essential role in the risk of osteoporotic fractures occurring in adulthood. It is considered that an increase of PBM by one standard deviation would reduce the fracture risk by 50%. As estimated from twin studies, genetics is the major determinant of PBM, accounting for about 60 to 80% of its variance. During pubertal maturation, the size of the bone increases whereas the volumetric bone mineral density remains constant in both genders. At the end of puberty, the sex difference is essentially due to a greater bone size in male than female subjects. This is achieved by larger periosteal deposition in boys, thus conferring at PBM a better resistance to mechanical forces in men than in women. Sex hormones and the IGF-1 system are implicated in the bone sexual dimorphism occurring during pubertal maturation. The genetically determined trajectory of bone mass development can be modulated to a certain extent by modifiable environmental factors, particularly physical activity, calcium and protein intakes. Prepuberty appears to be an opportune time to modify environmental factors that impinge on bone mineral mass acquisition.

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BACKGROUND: Adequate nutrition plays an important role in bone mass accrual and maintenance and has been demonstrated as a significant tool for the prevention of fractures in individuals with osteoporosis. OBJECTIVE: The aim of the present study was to evaluate bone health-related nutrients intake and its association with osteoporotic fractures in a representative sample of 2344 individuals aged 40 years or older in Brazil. METHODS: In a transversal population-based study, a total of 2420 individuals over 40 years old were evaluated from March to April 2006. Participants were men and women from all socio-economic classes and education levels living around the Brazilian territory Individuals responded a questionnaire including self reported fractures as well a 24-hour food recall. Nutrient intakes were evaluated by Nutrition Data System for Research software (NDSR, University of Minnesota, 2007). Low trauma fracture was defined as that resulting of a fall from standing height or less. Nutrient intakes adequacies were performed by using the DRI's proposed values. Statistical analysis comprises Oneway ANCOVA adjusted by age and use of nutritional supplements and multiple logistic regression. SAS software was used for statistical analysis. RESULTS: Fractures was reported by 13% of men and 15% of women. Women with fractures presented significantly higher calcium, phosphorus and magnesium intakes. However, in all regions and socio-economical levels mean intakes of bone related nutrients were below the recommended levels. It was demonstrated that for every 100 mg/phosphorus increase the risk of fractures by 9% (OR 1.09; IC95% 1.05-1.13, p < 0.001). CONCLUSION: The results demonstrated inadequacies in bone related nutrients in our population as well that an increase in phosphorus intake is related to bone fractures.

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RESUMO

Bone mass and strength achieved at the end of the growth period, simply designated as "Peak Bone Mass (PBM)", plays an essential role in the risk of osteoporotic fractures occurring in adulthood. It is considered that an increase of PBM by one standard deviation would reduce the fracture risk by 50 percent. As estimated from twin studies, genetics is the major determinant of PBM, accounting for about 60 to 80 percent of its variance. During pubertal maturation, the size of the bone increases whereas the volumetric bone mineral density remains constant in both genders. At the end of puberty, the sex difference is essentially due to a greater bone size in male than female subjects. This is achieved by larger periosteal deposition in boys, thus conferring at PBM a better resistance to mechanical forces in men than in women. Sex hormones and the IGF-1 system are implicated in the bone sexual dimorphism occurring during pubertal maturation. The genetically determined trajectory of bone mass development can be modulated to a certain extent by modifiable environmental factors, particularly physical activity, calcium and protein intakes. Prepuberty appears to be an opportune time to modify environmental factors that impinge on bone mineral mass acquisition.

La masa y fortaleza ósea conseguida al final del periodo de crecimiento, designada simplemente como masa ósea máxima (MOM), constituye un factor crítico en cuanto al riesgo de fracturas osteoporóticas en la edad adulta. Se considera que un aumento de MOM de una desviación estándar reduciría el riesgo de fracturas en 50 por ciento. Los estudios en gemelos han mostrado que la genética es el principal determinante de MOM, siendo responsable de 60 a 80 por ciento de su variación. Durante la maduración puberal el tamaño de los huesos aumenta mientras que su densidad mineral volumétrica permanece constante en ambos géneros. Al final de la pubertad la diferenciación sexual se debe básicamente al mayor tamaño de los huesos en hombres que en mujeres. Esto se consigue mediante una mayor deposición periosteal en los muchachos, confiriéndole así a la MOM mayor resistencia a las fuerzas mecánicas en hombres que en mujeres. Este dimorfismo sexual óseo que se presenta durante la maduración puberal se debe sobre todo a las hormonas sexuales y al factor de crecimiento insulínco 1 (IGF-1). La trayectoria genéticamente determinada de desarrollo de la masa ósea puede modularse hasta cierto punto mediante factores ambientales modificables, sobre todo la actividad física y la ingesta de calcio y proteínas. El periodo prepuberal parece ser el momento oportuno para modificar los factores ambientales que afectan la adquisición de masa mineral ósea.

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The frequency of osteoporosis and fragility fractures has been studied to a very limited extent in few developing countries. The aim of this paper is to review briefly the burden of osteoporosis and fragility fractures in these countries and to propose some strategies for the prevention and control of those conditions, considering barriers and facilitators for their implementation. The evolution of the demographic composition in most regions with developing countries shows a considerable increase in life expectancy and therefore, a significant growth in elderly population can be expected. Reports on the incidence of fragility fractures show figures in many of those countries that are comparable to those found in developed nations. Health resources (for acute treatment of fractures, their rehabilitation and chronic management, for diagnostic centers and drug therapy for osteoporosis) are limited in most of those regions and are allocated to other health priorities. Internationally accepted guidelines can be adapted to the realities of developing nations and may be promoted by organizations of health professionals and patients, but require endorsement and support by health authorities. The steps should include: (a) campaigns to increase awareness, both among the population at risk and relevant health workers; (b) the promotion of a preventive lifestyle in the general population; (c) the development of national or regional, evidence-based guidelines for the diagnosis and treatment of osteoporosis; (d) development and implementation of guidelines for the treatment of fragility fractures, their rehabilitation and prevention of falls; (e) collection of economic data on fractures and osteoporosis; and (f) development of country-specific fracture databases. These steps may help in reducing the increasing burden of osteoporotic fractures. Their implementation will require solid scientific basis and commitment from policy makers, health professionals, patient organizations, and ultimately the general population.

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METHODS: In a randomized, double-blind, placebo-controlled clinical trial, we evaluated the effect of a 2-year treatment with nandrolone decanoate (ND) on bone mineral density (BMD) of lumbar spine, femoral neck, and trochanter and on vertebral fracture rate, muscle mass, and hemoglobin levels. Sixty-five osteoporotic women older than 70 years were studied. Thirty-two patients received injections of 50 mg ND, and 33 received placebos every 3 weeks. All patients received 500 mg calcium tablets daily. RESULTS: Compared to baseline, ND increased the BMD of the lumbar spine (3.4% +/- 6.0 and 3.7% +/- 7.4; p < .05) and femoral neck (4.1% +/- 7.3 and 4.7% +/- 8.0; p < .05) after 1 and 2 years, respectively. The BMD of trochanter increased significantly only after the first year (4.8% +/- 9.3, p < .05). Compared to the placebo group, the ND group presented with significantly increased BMD of the trochanter and neck. ND significantly reduced incidence of new vertebral fractures (21% vs 43% in the placebo group; p < .05). ND showed a significant statistical increase in lean body mass after the first (6.2% +/- 5.8; p < .01) and second years (11.9% +/- 29.2; p < .01). In addition, a 2-year treatment with ND significantly increased hemoglobin levels compared to baseline (14.3%; p < .01) and placebo (p < .01). CONCLUSIONS: ND increased BMD, hemoglobin levels, and muscle mass, and reduced the vertebral fracture rate of elderly osteoporotic women.

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Osteoporosis has to be considered only as a risk factor for bone fractures and its measurement by the bone mass index has some limitations. The aim of treatment of osteoporosis is to reduce the frequency of fractures (especially at the vertebral and the hip) which are responsible for morbidity and mortality with the osteoporosis. It has been demonstrated that antiresorptive drugs (bisphosphonates, estrogens, raloxifen) as well as anabolic agents (synthetic parathormone) are useful for preventing fractures. Calcium and vitamin D supplementation is not sufficient to treat persons with osteoporosis. Choice of treatment depends of age, the presence or absence of prevalent fractures, and the degree of bone mineral density measured at the spine and hip. The main inconvenient for the adherence of treatment is the high cost of the medicaments and agents as well as the poor information given to the patients.

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En la actualidad la osteoporosis se considera solamente como un riesgo de fractura y por lo tanto se debe analizar en compañía de otros riesgos para decidir la conveniencia del tratamiento. Es más importante considerar la calidad ósea que confiere la resistencia, en la que la densidad ósea es uno de los varios componentes junto con la microarquitectura, la matriz y el recambio óseo. El tratamiento de la osteoporosis se hace en forma individual, considerando la edad y el antecedente de fractura, para así seleccionar varios recursos que se pueden agrupar en antiresortivos y anabólicos. Entre los primeros están los estrógenos, los bisfosfonatos y los moduladores selectivos del receptor de estrógenos como los principales; los anabólicos aún se encuentran en estudio y el más adelantado es la parathormona sintética. La administración de calcio y vitamina D no es suficiente para el tratamiento de la osteoporosis. El principal problema del tratamiento, que ha provocado una baja adherencia es el costo de los medicamentos y la falta de información sobre la necesidad de que el tratamiento sea a muy largo plazo.

Osteoporosis has to be considered only as a risk factor for bone fractures and its measurement by the bone mass index has some limitations. The aim of treatment of osteoporosis is to reduce the frequency of fractures (especially at the vertebral and the hip) which are responsible for morbidity and mortality with the osteoporosis. It has been demonstrated that antiresorptive drugs (bisphosphonates, estrogens, raloxifen) as well as anabolic agents (synthetic parathormone) are useful for preventing fractures. Calcium and vitamin D supplementation is not sufficient to treat persons with osteoporosis. Choice of treatment depends of age, the presence or absence of prevalent fractures, and the degree of bone mineral density measured at the spine and hip. The main inconvenient for the adherence of treatment is the high cost of the medicaments and agents as well as the poor information given to the patients.

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We evaluated the long-term use of synthetic salmon calcitonin in the management of osteogenesis imperfecta tarda and congenita. Forty-eight children, ranging in age from 6 months to 15 years, and two young adults, received synthetic salmon calcitonin 2 MRC units/kg three days a week and a daily oral calcium supplement of 230 to 345 mg. The annual fracture rate was decreased during calcitonin therapy as compared to the period preceding therapy. There was an increase in the ability of the patient to stand and move and in the subjective feeling of strength in the lower extremities during calcitonin therapy. There was also a significant improvement in radiographic bone density, as determined by the method of photodensitometry, in patients under 5 years of age. Long-term administration of synthetic salmon calcitonin may be beneficial to young children with osteogenesis imperfecta.

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