Influence of body composition on bone mass in postmenopausal osteoporotic women

We aimed at evaluating the relationship of lean and fat mass to bone mass in osteoporotic postmenopausal women. We invited 65 women who were being treated at the Sao Paulo Hospital osteoporosis outpatients` clinic to participate. Body composition and bone mineral density (BMD) measurements were performed using Dual-energy X-ray absorptiometry methodology (DXA). The mean age and weight were 69.7 +/- 6.4 years and 56.3 +/- 7.6 kg, respectively. Accordingly to the body mass index (BMI), 52.8% were of normal weight and 47.1% of the patients were overweight. Overweight women had significantly higher bone mass. Similarly, skeletal muscle index (SMI) showed a positive effect on BMD measurements and women with sarcopenia had significantly lower BMD measurements in total femur and femoral neck. In multiple regression analysis only lean mass and age, after adjustments to fat mass and BMI, were able to predict total body bone mineral content (BMC) (R(2) = 28%). Also lean mass adjusted to age and BMI were able to predict femoral neck BMD (R(2) = 14%). On the other hand, none of the components of the body composition (lean mass or fat mass) contributed significantly to explaining total femur BMD and neither body composition measurements were associated with spine BMD. These findings suggest that lean mass has a relevant role in BMC and BMD measurements. In addition, lower BMI and lean mass loss (sarcopenia) is associated to lower BMC and BMD of femoral neck and total femur and possible higher risk of osteoporotic fracture. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Effects of dietary lipid composition bioavailability and inulin-type fructans on mineral in growing rats

Objective: This study reports the effects of feeding with a combination of inulin-type fructans (ITF) and fish oil (FO) on mineral absorption and bioavailability as part of a semipurified diet offered to rats. Methods: Male Wistar rats (n = 24) were fed a 15% lipid diet (soybean oil [SO] or a 1:0.3 fish:soybean oil mixture [FSO]) and diets containing the same sources of lipids supplemented with 10% ITF (Raftilose Synergy 1) ad libitum for 15 d. Feces and urine were collected for mineral analyses during the last 5 d of the test period. Fatty acid composition was determined in liver and cecal mucosa homogenates. Liver and bone mineral analyses were performed by atomic absorption spectrophotometry. Bone biomechanical analyses were evaluated by a 3-point bending test. Results: Compared with the controls, ITF-fed rats had enlarged ceca and a significant decrease in cecal content pH (P < 0.001). The apparent mineral absorption was improved in these rats, and this effect was enhanced by dietary combination with FO for all minerals except for magnesium. Addition of ITF to the diet resulted in higher bone mineral content (calcium and zinc) and bone strength, but increased bone mineral content was only statistically significant in FO-fed animals. A decrease in liver iron stores (P = 0.015) was observed in rats fed FO, considering that ITF consumption returned to levels comparable to the SO control group. Conclusion: These findings confirm the positive influence of ITF on mineral bioavailability, which was potentiated by addition of FO to the diet. (C) 2009 Published by Elsevier Inc.

Impacts of limestone and nitrogen top dressing application on the potassium content in the soil profile and marandu-grass leaf concentration

Objetivou-se avaliar os efeitos de nitrogênio (0, 100, 200, 300 e 400 kg/ha.ano), com ou sem aplicação de calcário dolomítico em cobertura, sobre o teor de potássio (K) do solo nas profundidades de 0 a 5; 5 a 10; e 10 a 20 cm e a concentração de potássio na planta. O experimento foi realizado em Latossolo Vermelho distroférrico de relevo suavemente ondulado, disposto em esquema fatorial 5 × 2, em blocos casualizados, com quatro repetições. A adubação nitrogenada promoveu aumento linear na concentração de potássio na planta e no teor desse mineral na camada de 0 a 5 cm do solo. Ocorreu efeito de inibição competitiva entre a absorção de potássio e cálcio e entre potássio e magnésio. Embora uma fração significativa de potássio retorne à camada superficial do solo pelo resíduo de forragem, em decorrência da maior produção de massa, o aumento da concentração de potássio na planta nas mais altas doses de nitrogênio comprova a importância do suprimento de potássio para a planta, por intensificar a massa de forragem.

Effect of a novel soy fermented product enriched with isoflavones and calcium on bone tissue of rats.

The objective was to evaluate the effect of soy fermented product intake on the corporal weight and bone tissue of ovariectomized mature rats. This product was fermented with Enterococcusfaecium and Lactobacillus jugurti and enriched with isoflavones and calcium. The animals were divided in 5 groups: sham-ovariectomized; ovariectomized; ovariectomized treated with soy fermented product enriched with isoflavones and calcium; ovariectomized treated with soy fermented product enriched with calcium and ovariectomized treated with nonfermented product enriched only with calcium. In order to evaluate the effect of the tested product on bone tissue (femur and tibia), the following parameters were analyzed: length; mechanical assay of three points; density (Archimedes principle); mineral content; calcium content; measure of the trabecular widths. The corporal weight of group treated with soy fermented product containing isoflavones and calcium showed no statistical difference from sham-ovariectomized group and trabecular widths tended to have larger than ovariectomized group. However, there was no significant difference to the other evaluated parameters in result of the diverse treatments. Thus, soy fermented product enriched with isoflavones and calcium inhibited the increasing of corporal weight caused by ovariectomy and revealed a tendency to trabecular protection after castration.

A Modified Technique of Rat Tail Suspension for Longer Periods of Observation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

MINERAL COMPOSITION of RAW MATERIAL, SUBSTRATE and FRUITING BODIES of Pleurotus ostreatus IN CULTURE

In a culture of a Pleurotus ostreatus (oyster mushroom) strain, macro and micronutrients of the raw material and the initial and spent substrates were evaluated. Substrates were formulated with sawdust from Simarouba amara Aubl. and Ochroma piramidale Cav. ex. Lam., crushed Bactris gasipaes Kunth and crushed Saccharum officinarum (sugar cane). Samples were solubilized by means of acid digestion (nitric-peridrol). Ca, Mg, Fe, Cu, Zn and Mn were determined by atomic absorption spectrophotometry, Na and K by atomic emission, and P by colorimetry. The mineral composition of the fruiting body varied with the substrates, which made possible the production of a fruiting body rich in K, P Mg and Fe. Potassium was the mineral with the highest content in the fruiting body in all substrates tested (36.83-42.18g.kg(-1)). There was an increase of protein and mineral content in the spent substrate in relation to the initial one.

Bone mineralization in Brazilian adolescents: The years of maximum bone mass incorporation

Puberty is the fundamental period for bone mass (BM) acquisition. In this period mineralization is found to increase with levels of high bone formation. The critical years of intense bone anabolism deserve special attention, as adequate gain could minimize fracture risk in later years. The objective of this work was to study bone mineral content (BMC) and bone mineral density (BMD) in male adolescents with age bracket and maturation level. Sixty-one healthy male 10 to 19 year-olds were evaluated for calcium intake, weight, stature, BMI, puberty stage and BMC and BMD in the lumbar spine and femur. BM was measured by bone densitometry (DXA). Calcium intake was calculated by recording 3 days diet. Puberty stage was defined as per Tanner. Descriptive statistics was used with means and standard deviations, linear correlation, and analysis of variance for comparison between age groups, and the Tukey test (p<0.05). Linear correlation was positive and indicated body weight as the main correlation variable with BMD in both studied locations (p<0.01). BMC and BMD increased with age, differences were significant from 14 to 15 years, and when adolescents reached Tanner stage G4. These results showed a pronounced increase in bone mineralization, with the years after 14 to 15 being critical for BM acquisition in Brazilian adolescents.

Bone structure, strength and microhardness resulting after hindlimb unloading in rats

Introduction: Bone strength is influenced by a number of different determinants, such as mass, size, geometry and also by the intrinsic material properties of the tissue. Aims: The structure and mechanical properties of the femur were analyzed in aged (14 mo-old) animals submitted to hindlimb unloading (HU) for 21 days. Methods: Twenty Wistar rats were randomly divided into Control and HU groups and the femur was submitted to dual X ray absorptiometry (DXA), DIGORA radiographic density, mechanical compression testing and Knoop microhardness analyse in cortical and cancellous bone. Results: Femurs from HU group presented significantly lower failure load, decreased bone mineral density (BMD)/bone mineral content (BMC) in whole bone; proximal/distal epiphysis and middiaphyseal cortical bone measured by DXA were similar in the two groups; radiographic density from areas in proximal epiphysis was significantly lower in HU group, and microhardness measured at periosteal and endosteal levels were also signifcantly diminished in HU compared with Control group. Conclusion: Disuse induced damage in the trabecular femoral bone architecture with decisive effect on the head and trochanteric fossa, which became weaker. Bone diaphyseal cortical hardness also suffered effect of unloading, probably related to osteocyte/osteoblast activity.

The relationship between visceral fat thickness and bone mineral density in sedentary obese children and adolescents

Background: Among adults, obesity has been positively related to bone mineral density. However, recent findings have pointed out that abdominal obesity could be negatively related to bone density. The above mentioned relationship is not clear among pediatric populations. Therefore, this cross-sectional study analyzed the relationship between thickness of abdominal adipose tissue and bone mineral variables in sedentary obese children and adolescents.Methods: One hundred and seventy five obese children and adolescents (83 male and 92 female) with ages ranging from 6 to 16 years-old were analyzed. Bone mineral content and density were estimated by dual-energy X-ray absorptiometry and ultrasound equipment which estimated the thickness of the abdominal adipose tissue. Pubertal stage was self-reported by the participants.Results: The mean age was 11.1 (SD = 2.6). Thickness of the abdominal adipose tissue was negatively related to bone mineral density (r = -0.17 [r95%CI: -0.03;-0.32]), independent of gender, pubertal stage and other confounders (β = -0.134 ± 0.042 [β95%CI: -0.217; -0.050]).Conclusions: In sedentary obese children and adolescents abdominal obesity is negatively related to bone mineral density, suggesting a potential link between abdominal obesity and osteoporosis. © 2013 Júnior et al.; licensee BioMed Central Ltd.

Capacidade funcional, composição corporal e condições de saúde de idosos longevos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito do consumo de iogurte de soja suplementado com isoflavonas e cálcio sobre o tecido ósseo de ratas maduras ovariectomizadas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Perfil da nutrição mineral dos rebanhos leiteiros, na microrregião de Castanhal e no município de Uruará, Estado do Pará

O estudo é uma ação de pesquisa do projeto "Sustentabilidade da pecuária leiteira da agricultura familiar da Amazônia Oriental", desenvolvido pela Embrapa Amazônia Oriental e propôs determinar os principais problemas da nutrição mineral nos sistemas de produção leiteira de pequenas e médias propriedades na microrregião de Castanhal (MrC) e no município de Uruará (MuU), Estado do Pará. Como objetivos específicos visou definir as características da suplementação mineral efetuada nas propriedades, bem como analisar o conteúdo mineral das pastagens formadas de Brachiaria brizantha cv. Marandu. Para isso, foram utilizados dois estudos sendo que no primeiro foram definidas as características da suplementação mineral nos sistemas de produção leiteira de ambos os locais estudados através de um questionário/entrevista. Dos dados obtidos pelo questionário/entrevista foram extraídas 22 variáveis consideradas importantes que foram classificadas em quatro grupos principais. Utilizou-se a estatística descritiva aplicando-se o teste de Qui-quadrado ao nível de 5% de probabilidade para determinação das diferenças testadas. No segundo estudo foram colhidas amostras de Brachiaria brizantha cv. Marandu em duas propriedades da MrC e quatro do MuU. As amostras de forragem foram colhidas em dois períodos distintos do ano, final do período seco (novembro/1998) e final do período chuvoso (junho/1999) para determinação de cálcio (Ca), fósforo (P), magnésio (Mg), sódio (Na), potássio (K), cobre (Cu), zinco (Zn), ferro (Fe), manganês (Mn) e cobalto (Co). O delineamento experimental utilizado para a amostragem da forragem foi inteiramente casualisado considerando os dois locais estudados (MrC e MuU) como sendo dois fatores e os dois períodos do ano (chuvoso e seco) foram considerados como sub-parcelas. A análise de variância foi realizada pelo método de mínimos quadrados e o teste F foi utilizado ao nível de 5% para testar os efeitos. O teste de Tukey foi utilizado para comparação das médias. Na microrregião de Castanhal, a Brachiaria brizantha cv. Marandu não atendeu as necessidades de P, Na, Cu e Zn sugeridas para bovinos de corte, categoria vacas em lactação e demonstra a necessidade de suplementação mineral via cocho. Apesar da atividade leiteira ser mais antiga nessa microrregião, os criadores não conseguem distinguir as necessidades diferenciadas de requerimento dentro das categorias de produção animal. Esse desconhecimento deve ser considerado como um importante fator de restrição de produtividade. Particularmente nessa microrregião, a baixa concentração de P na forragem durante o período chuvoso parece agravar o problema da deficiência mineral por se tratar de um período de maior disponibilidade protéicoenergético da forragem, fazendo com que o animal requeira maiores quantidades do elemento fósforo na dieta. No município de Uruará, a Brachiaria brizantha cv. Marandu não atendeu as necessidades de P, Na e Cu, sugeridas pelo NRC (1986) para bovinos de corte, categoria vacas em lactação e demonstra também a necessidade de suplementação mineral via cocho. Nesse município, observou-se um baixo consumo de mistura mineral e as condições dos cochos eram precárias. A localização do cocho dentro do curral e o acesso somente durante o período de ordenha inibiu o consumo de mistura minera!. A freqüência elevada de relatos de apetite depravado, atraso no cio, fratura espontânea, diminuição do apetite e emagrecimento dos animais, são sintomas sugestivos de deficiência clínica de P e Cu sintetizam a baixa qualidade da nutrição dos animais neste local.

Association between bone mass and functional capacity among elderly people aged 80 years and over

Objetivo:Analisar a associação entre a massa óssea e capacidade funcional de idosos com 80 anos ou mais.Métodos:A amostra foi composta por 93 idosos entre 80 e 91 anos (83,2 ± 2,5 anos), 61 mulheres (83,3 ± 2,7 anos) e 32 homens (83,1 ± 2,2 anos) da cidade de Presidente Prudente. A avaliação da massa óssea foi feita pela absorptiometria de dupla energia de raios X (DXA), na qual foram mensurados os valores de conteúdo mineral ósseo (BMC) e densidade mineral óssea (BMD) do fêmur e da coluna (L1-L4). A capacidade funcional foi avaliada por meio dos testes de velocidade para caminhar, equilíbrio estático e força de membros inferiores contidos no questionário Saúde, Bem-Estar e Envelhecimento (Sabe). As variáveis da massa óssea e capacidade funcional foram categorizadas de acordo com os valores de mediana e a pontuação obtida nos testes, respectivamente. Para tratamento estatístico fez-se o teste qui-quadrado, o software usado foi SPSS (13.0) e o nível de significância estabelecido foi de 5%.Resultados:Os idosos do sexo masculino com maior desempenho nos testes funcionais apresentaram maiores valores de BMC de fêmur comparados com os de menor desempenho, resultado não encontrado quando avaliadas as mulheres.Conclusão:Dessa forma, a massa óssea do fêmur para idosos longevos do sexo masculino está associada à capacidade funcional. A avaliação constante da massa mineral óssea e a prática de atividade física ao longo da vida seriam medidas para prevenção das quedas em idosos.

Excess body fat negatively affects bone mass in adolescents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mineral Loss and Morphological Changes in Dental Enamel Induced by a 16% Carbamide Peroxide Bleaching Gel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)