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 São 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.

Cálcio dietético: estratégias para otimizar o consumo / Dietary calcium: strategies to optimize intake

O cálcio é um nutriente essencial necessário em diversas funções biológicas. Estudos têm demonstrado a associação entre o baixo consumo de cálcio e doenças crônicas, entre elas osteoporose, câncer de colón, hipertensão arterial e obesidade. Entretanto, grande parte da população brasileira apresenta consumo de cálcio abaixo do recomendado. Este artigo objetiva revisar os fatores endógenos (idade e estado hormonal) e exógenos (fitatos, oxalatos, sódio, compostos bioativos e vitamina D) que influenciam a absorção do cálcio, bem como as principais metodologias utilizadas para avaliar a absorção e biodisponibilidade desse nutriente. Discorre-se sobre os possíveis fatores para o baixo consumo de cálcio: 1) Hábito alimentar - substituição de leite por bebidas com baixo teor de cálcio como o refrigerante, refeições realizadas fora de casa e a não realização de refeições como o café da manhã; 2) Alto custo dos alimentos fontes de cálcio. Além disso, este artigo discute as estratégias para otimizar o consumo do cálcio, que incluem: 1) Aumentar o conhecimento sobre a importância do consumo de cálcio para a saúde e as principais fontes alimentares desse nutriente; 2) Aumentar a disponibilidade de alimentos fortificados com cálcio; 3) Uso de suplementos em grupos específicos - quando e como administrar os sais de cálcio.

Calcium is an essential nutrient required for numerous biological functions. Studies have demonstrated an association between low calcium intake and chronic diseases, such as osteoporosis, colon cancer, hypertension, and obesity. However, most Brazilians do not meet the adequate intake for calcium. This review focuses on the endogenous (age, hormonal state) and exogenous (phytate, oxalate, sodium, bioactive compounds and vitamin D) factors that can influence calcium absorption. The main methods used for evaluating calcium absorption and bioavailability. The potential factors for the low calcium intake: 1) Food habits - substitution of milk for soft drinks, eating away from home and skipping meals specially breakfast; 2) High cost of dairy food. Besides, this article discuss strategies to optimize calcium intake: 1) Increase knowledge of the relationship between calcium and health and the main food sources; 2) Increase availability of calcium-fortified foods; 3) Supplement use for target groups - when and how administrate calcium salts.