Muscle mass and strength may be key to improving lives of men with idiopathic vertebral fracture
MedWire News: Muscle mass and strength could be useful targets for increasing bone strength and physical functioning in men with idiopathic vertebral fracture, subsequently reducing their fracture risk and improving quality of life, say researchers.
Osteoporosis may be more common in women, but men are also at substantial risk for osteoporotic fracture once they reach the age of 50 years, which impacts heavily on their quality of later life and their future healthcare costs. Muscle mass is known to be reduced in men with idiopathic vertebral fracture and it is thought that this could have an adverse effect on patients' bone health.
The study, led by Jamie Macdonald, at Bangor University in the UK , looked at the body composition outcomes of routine idiopathic vertebral fracture management in men over a 6-year period.
Twenty patients with vertebral fracture were recruited, all less than 75 years of age and with fractures that were characterized from lateral radiographs of the thoracic and lumbar spine. The patients had a median of 1.5 fractures at the point of recruitment and 18 were prescribed pharmacologic treatment.
The control group consisted of 28 participants who were matched in age and height to the fracture patient cohort.
Bone mineral density (BMD) measurements and measurements of lean and fat mass were taken using dual-energy X-ray absorptiometry (DXA). Appendicular lean mass, or the total lean mass of all four limbs, was used as a measure of skeletal muscle mass as the main outcome measure in the study.
The study showed that although muscle mass was reduced in the fracture patients, it did not change significantly over the 6 years, unlike the control group, which experienced age-related decline (equivalent to -1.1kg per decade). The researchers describe this finding as "novel and unexpected" and suggest that this could be an indirect effect of increased activity due to the reduction of pain thanks to pharmacologic treatment.
The paper, published in the journal Arthritis Care & Research, reports a relationship between muscle mass and bone strength as represented by a correlation between loss of appendicular lean mass and the loss of BMD at the femoral neck in the men with idiopathic vertebral fracture.
Although muscle strength correlated with physical function and physical function correlated with quality of life on the Short Form-36, muscle mass did not significantly correlate with any of these three variables in the fracture group. However, the authors write that their quality of life model may be over-simplified.
From this study they conclude that "potential targets for intervention may include reducing pain and increasing muscle strength by both medical and lifestyle interventions," but future studies will need to address why quality of life is reduced in men with idiopathic vertebral fracture.
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By Chloe McIvor