The Diagnostic Accuracy of Biological Markers of Sarcopenia, Sarcopenic Obesity, and Osteosarcopenia: Protocol for a Systematic Review and Meta-Analysis.

Background and aims: Sarcopenia is the accelerated loss of skeletal muscle mass and function associated with aging, and can significantly impact a person's quality of life. Sarcopenia can also occur with other health conditions, such as excess adipose tissue and bone weakness. The presence of multiple long-term conditions can exacerbate sarcopenia, and it has been observed in tandem with a variety of chronic illnesses. Biological markers can act as an early identifier or predictor of disease, enabling simple surveillance and prompt treatment. The need for effective screening and intervention has become more important as our population ages. This protocol outlines our approach to summarize the evidence on the diagnostic accuracy of various blood-based biomarkers for diagnosing sarcopenia, including sarcopenic obesity and osteosarcopenia, through a systematic review and meta-analysis.

Methods: The protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Diagnostic Test Accuracy Studies (PRISMA-DTA) 2018 statement and prospectively registered (PROSPERO: CRD42024609060). A comprehensive literature search using electronic databases including MEDLINE, Embase (via SCOPUS), CINAHL, Cochrane, and Web of Science, will be conducted. The review will include studies that meet the specific inclusion criteria, and the risk of bias in the included studies will be assessed using the Quality Assessment of Diagnostic Accuracy 2 quality assessment tool (QUADAS-2). A meta-analysis will be conducted using random-effects approaches, based on the level of heterogeneity. Subgroup and sensitivity analysis will be performed if necessary.

Results: The results of this review will be reported in accordance with PRISMA-DTA standards, and published in a peer-reviewed journal.

Conclusion: The proposed systematic review and meta-analysis will assess the diagnostic accuracies of potential blood-based biomarkers for screening sarcopenia, sarcopenic obesity, and osteosarcopenia. The results will provide important evidence on the use of biomarkers to diagnose sarcopenia and its associated syndromes, which can inform the development of targeted screening and intervention in research and practice.