Our muscles are important for good physical health. We can assess the health of muscles using two measures: muscle mass, and muscle fat infiltration. Muscle mass is important for maintaining the body’s strength and keeping us mobile. Higher levels of muscle fat infiltration (fat tissue inside the muscles) are associated with a higher risk of health conditions including type 2 diabetes and heart disease.
There is some previous evidence suggesting that low muscle mass and high muscle fat infiltration are both related to a higher risk of death. Furthermore, a study carried out with people with liver disease found that these factors were particularly dangerous when they occurred at the same time. However, it is not yet clear how this combination relates to mortality in the general population, because high-quality images of muscle tissue (such as CT or MRI scans) are usually only taken in situations where people are already unwell.
Therefore, in order to learn more about the relationship between muscle health and mortality in the general population, CoMorMent researchers analysed medical images taken from 40,000 participants from the general population. To do this, they used UK Biobank, a dataset which combines health information from a large number of UK volunteers. They found that people who had low muscle mass combined with high muscle fat infiltration were more than three times more likely to die during the study period when compared to people who did not have these risk factors.
In fact, when taking multiple health factors into account, having this combination of low muscle mass and high muscle fat infiltration was just as dangerous as smoking. These findings highlight a particular biological pattern which clinicians could use to identify patients who are at greater risk and would benefit from a higher level of support.
