A study of individuals over 65 years old showed that all-cause mortality risk increased nearly 63-fold in women with low appendicular muscle mass. The risk of dying increased 11.4-fold in men (patient undergoing DXA body composition and bone density scan.
Evaluating body composition, especially appendicular muscle mass, can be an effective strategy for predicting longevity in people over 65 years of age, according to a study conducted by researchers at the University of São Paulo's Medical School (FM-USP) in Brazil.
The appendicular muscles are the muscles that move the appendages or extremities - the arms and legs. They also play a key role in stabilizing the shoulders and hips.
The researchers studied a group of 839 men and women over the age of 65 for approximately four years. They observed that all-cause mortality risk increased nearly 63-fold during the follow-up period in women with low appendicular muscle mass and 11.4-fold in men.
An article with results of the study, which was supported by FAPESP, is published in the Journal of Bone and Mineral Research.
"We evaluated the body composition of this group, focusing 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," Rosa Maria Rodrigues Pereira, Full Professor and Head of Rheumatology at FM-USP and principal investigator for the study, told Agência FAPESP.
Body composition was determined by dual energy X-ray absorptiometry (DXA), also known as bone density scanning, using a densitometer purchased with funding from FAPESP during a previous project led by Pereira to assess the prevalence of osteoporosis and fractures in older women living in Butantã, a neighborhood in western São Paulo city. The same cohort of individuals over 65 years of age was studied in both projects.
"Participants were selected on the basis of the census performed by IBGE [Brazil's national census bureau]. The sample was representative of the older members of the country's population," Pereira said.
The study sample comprised 323 men (39%) and 516 women (61%). The frequency of low muscle mass was approximately 20% for both men and women.
The gradual loss of muscle mass and quality associated with aging is known as age-related sarcopenia. Approximately 46% of Brazilians aged 80 or older have sarcopenia, according to the Brazilian Association of Geriatrics and Gerontology.
Especially when combined with osteoporosis, sarcopenia can increase the vulnerability of older people in that they become more prone to falls, fractures and ot...
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