We have three types of muscles within our body. Skeletal muscles are those under our control and allow us to move. An example would be our biceps. Our heart is a massive muscle that beats without conscious control. So too do the so-called smooth muscles. These line the hollow organs of our body including our arteries and veins.

Medicine defines sarcopenia as the age-related loss of skeletal muscle mass and strength. Doctors use different ways of measuring it. Some use simple tests of strength such a grip test. Others use sophisticated scanning tools that can measure muscle mass directly. We all have a mental image of frail older people. They have trouble walking , climbing stairs and even getting out of chairs.

Depending on the measure most estimates are that 10-15% of people will have sarcopenia. A large study in Iceland showed an incidence of only 7.3%. Other multinational reviews have suggested that it is more common in European than Asian countries. This increases with age and with the onset of chronic illness. For sufferers it can start in the forties. By the eighties up to 50% of muscle mass can have disappeared. It declines by roughly the same amount each decade.

Outcomes

Loss of muscle mass increases the sense of fatigue. It limits our ability to have a normal life. Climbing stairs can become an issue. The effects can be more extreme. The incidence of falls is much higher in sarcopenia sufferers. Falls and fractures as we age can lead to complications. It has also been shown to be a cause of other chronic diseases particularly arthritis. Our chances of dying increase.

Sarcopenia changes the ability of our muscles to regenerate. There are special cells. They are activated when we use our muscles intensively or injure them. The disease slows down the process and seems to reduce the number of these cells. It takes our muscles longer to recover and the regeneration may not be so successful.

Causes of Sarcopenia

There are a number of causes that have been identified. Some are under our control and others not. Many are associated with ageing. Some are caused by other diseases which are themselves age related. We can control our activity levels and what we eat. Both are associated with the skeletal muscle loss. There is a vicious circle. Muscle loss causes fatigue. Fatigue means that we are less active. Low activity levels accentuate the fatigue. Obesity can reduce activity levels. Sarcopenia is associated with obesity. Poor nutrition itself has been identified as an independent cause. Protein deficiency is one known factor.

Hormonal changes in men and women can have an impact. Inflammation levels in the body can cause sarcopenia if they last for long periods. Such inflammation is often associated with stress. Inflammation seems to influence the ability of muscles to regenerate. There are pathways from the underlying molecular changes. These often come with ageing.

Can You Fix Sarcopenia?

Treatments are an emerging field. A recent review highlights the limited range of options. Three quarters of all studies have focused on only exercise and nutrition. There have been few pharmaceutical studies and the results have been negative. There have been studies of nutraceuticals. They have looked at the impact of different vitamins and natural products. These clinical studies have shown little benefit from such supplements. Direct hormone treatment has shown little impact. Researchers have concluded that there is no simple cause. Instead there are multiple interrelated causes. There are no “magic pills” yet.

There is one thing known to work . That is exercise, particularly resistance exercises. It works at all ages. That huge study in Iceland looking at people over a five-year period. The average age at the start of the study was 75. The incidence of sarcopenia was 7.3%. Five years later that had jumped to 16%. However, there was a huge range of outcomes. They depended on how much exercise each individual had taken in those 5 years. The least active group had an incidence of 14.8%. The most active group 9.0%. The increase in sarcopenia seems to be inevitable but the rate controllable.

Nearly half of all nursing home residents in the US suffer from sarcopenia. It is often not made any better by well meaning health workers. Bed rest, inactivity and poor nutrition can accelerate the process. There is even a name for sarcopenia caused by health workers: iatrogenic. Increased protein in the diet and regular exercise can reverse the trend even for this group.

The inter-related nature of the causes is shown by recent studies. Exercise reduces inflammation. It also reverses some of the changes at the molecular level. Obviously, exercise will also improve cardiovascular activity. This is one way it can reduce inflammation. The exact pathway by which exercise helps has yet to be fully understood. Other Newsletters have shown that exercise can have many other benefits. There can be cognitive and physical health benefits. It is recommended at any age.