Biomarkers of sarcopenia: an unmet need

Abstract Background Sarcopenia is a syndrome characterized by a progressive decline in muscle mass and strength, with subsequent deterioration of functional performance and increased morbidity and mortality. Its emergence may be associated with disorders that are not limited to the elderly. The multifactorial nature of sarcopenia is a major barrier to diagnosis. Several risk factors contribute to the development of sarcopenia, including age, gender, and amount of physical activity. Additionally, the pathophysiology of sarcopenia involves inflammatory conditions, endocrinal dysfunction, and metabolic alterations. Several studies have proposed numerous molecules that may be linked to the pathogenesis of sarcopenia and could be useful in the future; however, there is an unmet need to discover a sensitive, reliable, and cost-effective biomarker of muscle aging. Main text The objective of this research is to highlight different biomarkers of sarcopenia that reflect its multifactorial pathophysiology. A narrative review was carried out through a series of literature searches in the database MEDLINE/PubMed focusing on sarcopenia biomarkers. The following search terms were used: “sarcopenia,” “osteosarcopenia,” “muscle ageing,” “muscle failure,” “sarcopenic obesity,” “weakness,” “biomarkers,” “frailty,” “comorbidity,” “functional disability,” and “inflamm-aging.” The studies were observational and peer-reviewed. They were all carried out at a referral center, hospital, or in the community. The articles chosen all contained information about sarcopenia. Case reports and articles that did not assess people's muscle aging and sarcopenia were not considered. Conclusion Despite the availability of numerous functional, imaging, and biological sarcopenia markers, the inherent limitations of the assessment tools make it difficult to objectively measure the various sarcopenia domains. A valid and reliable biomarker of sarcopenia has yet to be identified. The identification of “gold standard” evaluation techniques that should be systematically used is also impacted by the variability of the populations to be assessed. In this context, the establishment of an international consensus adopting a multi-biomarker approach may be of utmost importance to tackle the different aspects of this multifactorial health-related problem.