Muscle Loss during Old Age Linked to Changes in Nervous System

Muscle Loss during Old Age Linked to Changes in Nervous System

Muscle loss during old age is mainly caused by loss of nerve signals. Researchers from Manchester Metropolitan University, the University of Waterloo, Ontario, and the University of Manchester noticed 30 percent decline in nerves controlling leg muscles as individuals cross age of 75. The study team checked nerve signals among 168 study subjects and compared the results to individuals with more physical activity or athletic background. With aging, the leg muscles become weaker and they also shrink.

Researchers checked muscle tissue in detail using magnetic resonance imaging (MRI). They also estimated the size and number of nerves in the region by evaluating signal activity.

As muscle loss occurs, people find it difficult to move, climb stairs and perform basic tasks like getting up from a chair. The condition becomes worse if an individual is overweight. The study team noticed that healthy muscles have a protective mechanism. The surviving nerves send our new branches which save muscles from wasting away. This phenomenon is stronger among individuals with healthy muscle mass and individuals who have been engaged in athletic activity.

When the internal protective mechanism is not successful and nerves are unable to send out new branches, it can result in extensive muscle loss, the research team added. This can result in a condition called sarcopenia, which affects estimated 10 percent to 20 percent of people aged over 65 years.

It is still unclear why some people perform better in keeping healthy muscle mass and stronger nerve connections. The research team is still trying to evaluate if regular exercise in middle- and older-age slows the process of muscles becoming disconnected from the nervous system. It is also possible that with adequate physical activity, the chances of nerve branching get better and offer support to declining muscle mass.

Jamie McPhee, the senior author on the research and a professor with Manchester Metropolitan University, added, "Our challenge now is to find ways to increase the success of nerve branching to rescue detached muscle fibers and thereby reduce the numbers of older people in our neighborhoods with low muscle mass and muscle weakness."

Regular physical activity has been linked with better overall health in many studies conducted in the past. Keeping a healthy weight, reducing stress and engaging in regular physical activity is the best way to lead a healthy lifestyle.

Details of the research have been published in the Journal of Physiology.