Are we one step closer to discovering the elixir of youth? Scientists identify the enzyme that causes age-related muscle wasting by inhibiting enzyme they can reduce levels of hormone that triggers it.
The University of Birmingham study explored the role played by the enzyme '11β-HSD1' in the degenerative effects of ageing, including sarcopenia - age-related muscle wasting. Researchers found higher levels of the enzyme, which is responsible of activating the steroid hormone cortisol, in the muscles of older women. They examined 134 healthy volunteers aged between 20 and 80 years old.
Volunteers underwent physical and biochemical tests, including body composition analysis (how much fat they had), grip strength analysis, biochemical profiling, urine tests and biopsy of the large, outer thigh muscle. The expression of the enzyme was found to be increased 2.72-fold in women aged over 60 years old, compared to those aged between 20 and 40. In male participants, no difference was seen.
High levels of the enzyme were found to be linked to increased levels of cortisol, reduced grip strength, insulin resistance and a poorer body composition profile.
Dr Zaki Hassan-Smith, from the University of Birmingham, said: 'As yet, we don't know why it appears to only occur in women, it is obviously an interesting area for further research. We are planning to look at whether hormones such as oestrogens could be involved.'
The team wanted to investigate novel ways of increasing the healthy life span - the years which people can maintain active lifestyles without the debilitating impact of muscle wasting. Drawing on expertise from both the University of Birmingham and Queen Elizabeth Hospitals Birmingham, they applied their knowledge of Cushing's syndrome to the new problem. Cushing's is hormonal disorder caused by high levels of cortisol. Patients suffer from the syndrome see marked changes in their body composition. The effects can be devastating for patients who can develop features such as muscle wasting and weakness, weight gain, thinning of the bones, diabetes, high blood pressure and heart disease.
Dr Hassan-Smith said: 'Looking at this particular enzyme seemed like an intriguing way forward.
'We knew how it works in relation to Cushing's Syndrome, which is characterised by similar symptoms, and thought it would be worthwhile applying what we knew to the ageing population.'
Currently there are no treatments for sarcopenia, the team explained. But pharmaceutical companies are developing and testing ways to block or switch off the enzyme, with a focus on treatments for conditions including diabetes. The team is excited about taking the results of their study forward into future research, with one eye on adapting the inhibitors already in development to combat muscle ageing.
Dr Hassan Smith added: 'The next stage is a "proof of concept" study to look at the effects of these inhibitive pharmaceuticals on muscle function, before opening it up into a clinical trial. It's an as yet unexplored area that could yield beneficial results for a problem that is becoming more prevalent as our lifespans increase.'
About: Dr Hassan Smith
Read: the news article in the Daily Mail
