A new study has revealed that the level of appendicular muscle mass (muscles that move the arms and legs) could predict how long people over the age of 65 will live. The study, published in the Journal of Bone and Mineral Research, was conducted by researchers at the University of São Paulo's Medical School in Brazil.
The decline of skeletal muscle with age is called sarcopenia and is one of the most important causes of functional decline and loss of independence in adults.
The researchers looked at 839 participants over the age of 65 using clinical data, laboratory exams and body composition by dual-energy X-ray absorptiometry (DXA). The researchers also analysed bone density, blood samples and responses to questionnaires in order to evaluate diet, consumption of alcoholic beverages, smoking, physical activity and presence of chronic diseases including diabetes, high blood pressure and dyslipdemia (an abnormally high level of fat in the blood).
What experts had to say
Rosa Maria Rodrigues Pereira, Professor and Head of Rheumatology at FM-USP and principal investigator for the study said, "We evaluated the body composition of this group, focusing on on appendicular muscle mass, subcutaneous fat and visceral fat. We then sought to determine which of these factors could predict mortality in the ensuing years. We concluded that the key factor was the amount of appendicular lean mass."
Using dual energy X-ray absorptiometry (DXA), also known as bone density scanning, researchers were able to determine body composition. This was done by using a densitometer which was purchased during a previous study which assessed the prevalence of osteoporosis and fractures in older women living in a western São Paulo city. The same individuals over the age of 65 were studied in both projects.
When the four year period ended, 43.2% had died from cardiovascular problems and 15.8% of volunteers had died. The mortality rate was 20% for men and 13% for women in this sample.
Sarcopenia is preventable
The Brazilian Association of Geriatrics and Gerontology states that sarcopenia affects 46% of Brazilians 80 years and older. When combined with osteoporosis, it can increase the vulnerability of older people as they become more prone to physical injuries, falls and fractures. Based on the characteristics of the community, researchers were able to determine an equation which revealed which individuals can be considered to have sarcopenia.
Sarcopenia is preventable and can be reversed with physical exercise and muscle toning.
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