Pill could stop old people becoming frail

BEING old may not necessarily mean being frail in future, thanks to new research on why muscles weaken with age.

The work could potentially lead to a pill that reverses muscle loss in the elderly.

An experimental drug called S107 has been shown to strengthen mice with an equivalent human age of 70. A similar drug is now undergoing clinical trials for the treatment of heart failure, say scientists.

Skeletal muscles naturally wither and weaken with age, a phenomenon known as sarcopenia. The effect, which begins to appear at about the age of 40 and accelerates after we reach 75, is a major cause of disability in the elderly.

While exercise can help counter age-related muscle loss, there is no way it can be treated.

The new research from the US suggests sarcopenia occurs when calcium leaks from a group of proteins in muscle cells. This triggers a chain of events that ultimately blocks the ability of muscle fibres to contract.

The proteins responsible for the leakage, ryanodine receptors, are involved in the development of abnormal heart rhythms and heart failure. Two years ago, it was discovered they also contribute to the genetic disease Duchenne muscular dystrophy, which causes muscle wasting and early death.

Professor Andrew Marks, from Columbia University Medical Centre in New York, said: "This is a completely new concept - that the damage that occurs in ageing is very similar to what happens in muscular dystrophy. Thus, as we age, we essentially develop an acquired form of muscular dystrophy."

Prof Marks said he had found a link between sarcopenia, muscular dystrophy and highly reactive and harmful molecules called oxygen free radicals.