Men and osteoporosis

BACKGROUND: While strict criteria have been developed for defining osteoporosis in women (bone mineral density measurements more than 2.5 standard deviations below the mean for young adult normal women, i.e. t-score value < -2.5), there still remains a controversy regarding the definition in men. Spinal fractures occur in 5% and hip fractures in 6% of men older than 50 years. There are significant differences between men and women with respect to the pathogenesis of osteoporosis, underlying medical conditions and postfracture sequelae.

OBJECTIVE: To provide an overview of the pathogenesis, diagnosis and prevention of osteoporosis in men.

DISCUSSION: Osteoporosis is increasingly recognised. Data from the Dubbo Osteoporosis Epidemiology Study suggests that 30% of men in Australia aged over 60 years will suffer from an osteoporotic fracture. It is estimated that 30-60% of men presenting with spinal fractures will have another illness contributing to their bone loss. Osteoporotic fractures in men are associated with higher morbidity and mortality than in women. Lifestyle changes together with daily calcium supplementation should be implemented and vitamin D3 should be considered in men with osteopenia.

Squeeze pin implementation in a high pressure die casting

This paper discusses the implementation of hydraulically operated squeeze pins to reduce porosity formation in cast aluminium bearing caps. Two complete sets are cast in an eight-cavity die with a 2000t cold chamber high pressure die casting machine. The initial die configuration used a sliding core assembly with stationary pins to core a through hole in a thick section of the front cam caps. This configuration resulted in high post machining scrap rates, primarily due to porosity associated with solidification shrinkage. Replacement of the sliding core assembly with a squeeze pin unit substantially reduced shrinkage porosity in the critical region, with consequent reductions in the scrap rate. The squeeze pins are actuated 1.5s after the piston reaches the high shot changeover position, but can be successfully engaged between I and 3.5 seconds after high shot changeover. Density measurements and visual inspection confirmed the substantial improvement in porosity levels in the critical region of the castings.

Osteo-cise : Strong bones for life': protocol for a community-based randomised controlled trial of a multi-modal exercise and osteoporosis education program for older adults at risk of falls and fractures

Background : Osteoporosis affects over 220 million people worldwide, and currently there is no 'cure' for the disease. Thus, there is a need to develop evidence-based, safe and acceptable prevention strategies at the population level that target multiple risk factors for fragility fractures to reduce the health and economic burden of the condition.

Methods : The 'Osteo-cise: Strong Bones for Life' study will investigate the effectiveness and feasibility of a multi-component targeted exercise, osteoporosis education/awareness and behavioural change program for improving bone health and muscle function, and reducing falls risk in community-dwelling older adults at an increased risk of fracture. Men and women aged 60 years or above will participate in an 18-month randomised controlled trial comprising a 12-month structured and supervised community-based program and a 6-month 'research to practise' translational phase. Participants will be randomly assigned to either the 'Osteo-cise' intervention or a self-management control group. The intervention will comprise a multi-modal exercise program incorporating high velocity progressive resistance training, moderate impact weight-bearing exercise and high challenging balance exercises performed three times weekly at local community-based fitness centres. A behavioural change program will be used to enhance exercise adoption and adherence to the program. Community-based osteoporosis education seminars will be conducted to improve participant knowledge and understanding of the risk factors and preventative measures for osteoporosis, falls and fractures. The primary outcomes measures, to be collected at baseline, 6, 12, and 18 months, will include DXA-derived hip and spine bone mineral density measurements and functional muscle power (timed stair-climb test). Secondary outcomes measures include: MRI-assessed distal femur and proximal tibia trabecular bone micro-architecture, lower limb and back maximal muscle strength, balance and function (four square step test, functional reach test, timed up-and-go test and 30-second sit-to-stand), falls incidence and health-related quality of life. Cost-effectiveness will also be assessed.

Discussion : The findings from the Osteo-cise: Strong Bones for Life study will provide new information on the efficacy of a targeted multi-modal community-based exercise program incorporating high velocity resistance training, together with an osteoporosis education and behavioural change program for improving multiple risk factors for falls and fracture in older adults at risk of fragility fracture. Trial Registration: Australian New Zealand Clinical Trials Registry reference ACTRN12609000100291

Osteopaenia - a marker of low bone mass and fracture risk

Areal bone mineral density is commonly categorised into normal bone mineral density, osteopaenia and osteoporosis on the basis of nominal thresholds recommended by the World Health Organization. However, bone mineral density is a continuous variable and there is a strong association between lower bone mineral density and greater risk for fracture. Fracture risk is not negligible in persons with moderate deficits in bone mineral density. Although absolute fracture risk is greatest for individuals with osteoporosis, more than half of the fractures arise from those with osteopaenia, and even normal bone mineral density, a probable consequence of greater numbers of individuals at risk in these categories. However, areal bone mineral density measurements used commonly in clinical practice do not detect differences in bone tissue properties, geometry and microarchitecture, which contribute to bone strength. Newer technologies such as high-resolution peripheral computed tomography have the advantage of assessing trabecular and cortical components of bone separately, in addition to geometric characteristics of the skeleton. Quantifying these parameters and considering clinical risk factors that affect fracture risk independent of bone quantity and quality, may better discriminate between high- and low-risk individuals. This would improve the decision-making for targeting appropriate interventions, either lifestyle or medication, to reduce thepublic health burden of fractures.

Effect of counterpressure during equal-channel angular pressing on nanoporosity formation in ultrafine-grained copper

Results of small-angle X-ray scattering and high-precision density measurements showed that the application of counterpressure during the equal-channel angular pressing (ECAP) of ultrafine-grained copper leads to a decrease in nanoporosity and an increase in mechanical properties of the ECAP-processed metal.