Deeper causes of muscle loss in older people revealed by research studies

Southampton researchers have revealed new insights into age-related muscle loss and potential contributors to a statin-associated side effect on muscle.

The discoveries could enable new treatments to be developed for older people. These could help reduce this side effect of statins and protect muscle health in later years.

The two studies were led by experts at the NIHR Southampton Biomedical Research Centre.

Looking at the underlying biology

We naturally lose muscle mass and strength as we age. However, the rate at which this occurs is not the same for everyone. This means some people become weaker at a younger age, increasing the risk of falls and loss of independence in older adults.

New research could shine a light on why this process differs from person to person. It has been published in the Journal of Cachexia, Sarcopenia and Muscle.

Drs Mark Burton and Emma Garratt are first authors on the paper.

The results reveal differences in muscle cell populations from 132 participants aged between 72 and 83 years from the Hertfordshire Cohort Study.

Muscle cell populations were found to exist in different states which were linked to measures of muscle health. This finding increases our understanding of what may go wrong in muscle disease.

Investigating statin side effects

Statins are commonly prescribed to reduce the risk of cardiovascular disease. However, they are known to have side effects that affect muscle health.

These include muscle pain, weakness and reduced function. Collectively, they are referred to as statin-associated muscle symptoms (SAMS). This could accelerate age-related muscle loss, meaning older people become weaker at a younger age.

The second Southampton paper has been published in JCSM Communications. This aimed to investigate the underlying mechanisms that cause SAMS.

PhD researcher Maisha Chaudhery was first author, with Dr Emma Garratt a senior author.

The researchers used muscle biopsies from 11 older women and grew muscle cells from them in the laboratory. They added different amounts of the most commonly prescribed statin, atorvastatin, to these cells.

Muscle cells exposed to higher doses of atorvastatin showed more signs of ageing and reduced growth. The researchers found many key gene regulatory pathways involved in muscle maintenance, function, and health were disrupted in these cells.

These pathways could provide a key target for future treatments to reduce the muscle side effects of statins and protect older people’s muscle health for longer.

“Age-related muscle loss can mean older people become frail and lose the ability to be independent,” said Dr Burton, who was an author on both papers.

“Loss of muscle not only affects movement and strength but also changes metabolism, which is key for overall health.

“These studies reveal new insights that could aid in the development of future treatments, which could enable people to live independently for longer as they age.”