Biomarkers for sarcopenia: reductionism vs. complexity

Sarcopenia, the progressive and generalized loss of muscle mass and strength/function, is a major health issue in older adults, given its high prevalence and burdensome clinical ramifications. The absence of a unified operational definition for sarcopenia has hampered its full appreciation by healthcare providers, researchers and policy-makers. At the same time, this unresolved debate and the complexity of musculoskeletal aging pose major challenges to the identification of clinically meaningful biomarkers. This review summarizes the current knowledge on biological markers for sarcopenia, including a critical appraisal of traditional procedures for biomarker development in the field of muscle aging. As an alternative approach, we illustrate the potential advantages of biomarker discovery procedures based on multivariate methodologies. Relevant examples of multidimensional biomarker modeling are provided with an emphasis on its clinical and research application.