Sarcopenia is characterised by progressive muscle mass, function, and strength loss associated with aging, and is estimated to affect 10-30% of individuals. It results in the deterioration of functional performance and independence, and those with the conditions experience increased frailty, morbidity, and mortality. Diagnosis of sarcopenia is most commonly done through objective functional/strength testing and imaging; however, these can be expensive and unsuitable for general clinical practice. Akin to automated frailty indexes, there is a need for inexpensive, objective, and accessible ways to identify people with sarcopenia. In recent years, various indicators of normal biological processes emerged in the literature, but require validating on a larger, more varied dataset.
Sarcopenia is accelerated and more prevalent in those with two or more chronic illnesses, called Multiple Long-Term Conditions (MLTCs). There are roughly 9 million (about 15% of the population) people in England living with MLTCs, and this number is growing, in line with the aging population. Much remains unclear about the relationship between sarcopenia and MLTCs. The key research questions of this project are 1. What is the validity of novel blood-based biomarkers for adverse body composition (sarcopenia, sarcopenic obesity, osteosarcopenia, muscle fat infiltration)? 2. What is the prevalence of sarcopenia (assessed using objective and blood biomarkers) across different MLTCs, and is this different in specific LTCs? 3. Can these biomarkers predict the development of sarcopenia? 4. What is the association of sarcopenia with long-term clinical outcomes (e.g., mortality, hospitalisation) in people with MLTCs? And does this risk differ with different conditions? 5. In those without existing LTCs, can sarcopenia biomarkers be used as a prognostic ‘red flag’/biomarker for the development of LTCs?
