Age-related muscle and mobility loss due to genetics
Genetic variations in a mitochondrial enzyme are responsible for age-related changes in mobility, said University of Southern California (USC) School of Gerontology postgraduate student Osvaldo Villa, referring to a study that sought to understand why some older adults remained active as they aged while others found daily activities increasingly difficult.
Villa and USC colleagues had screened the roundworm Caenorhabditis elegans (C. elegans) to find specific genetic factors that led to a loss of mobility over time. They found variations in a mitochondrial gene called ALH-6 was associated with oxidative stress, a process that can cause cell damage. Worms with these variations were less able to crawl and swim as time progressed.
In a concurrent study, the USC team found that older adults with certain variations in the human equivalent of this gene, called ALDH4A1, had noticeably slower walking speeds and reduced hand strength as they aged. Participant data was obtained from the US Health and Retirement Study – it contained genetic and health information from more than 36,000 US adults aged 50 and above.
“These findings suggest that variations in the ALH-6 or ALDH4A1 gene can impact muscle aging in C. elegans and humans, and may help predict muscle health in people as they age,” said USC postgraduate student Nicole Stuhr.
On top of diet and other factors, many more genes interact with each other to influence age-related changes in strength and mobility, so the researchers admit to needing more studies to understand all of the genes involved.
Many people progressively lose muscle mass and strength as they age, which can reduce their quality of life and contribute to falls, broken bones, and more. A lack of exercise, poor diet, and a growing variety of genetic factors also contribute.
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