Proteomics and frailty: a clinical overview.

INTRODUCTION: Frailty is consequent to age-dependent deregulation of several biological pathways and systems, encompassing namely sarcopenia, age-associated hormonal derangements, inflammation, and nutritional or metabolic deficiencies. Although the prevalence of frailty is usually between 10% and 20% in the general elderly population, its overall burden will increase exponentially along with the predictable prolongation of life expectancy. Risk prediction and early diagnosis will hence become pivotal for mitigating the clinical, social, and economic impact of this condition. The currently available research suggests that no single laboratory biomarker can efficiently help predicting or diagnosing frailty. However, its multifaceted pathogenesis suggests that a multi-marker approach, preceded by preliminary identification of specific proteomic signatures, may be the most promising strategy in frailty diagnostics. Areas covered: This review critically analyzes recent proteomic studies exploring protein profiles in non-frail and frail subjects. Expert commentary: Results of some recent proteomic studies attest that muscle proteome, chronic low-grade inflammation (inflammaging), along with characteristic vascular and hemostasis proteomic profiles, may help predict or diagnose frailty. Larger prospective studies are needed for confirming these findings and enabling their replication in real life scenarios. Albeit proteomic research in the field of age-dependent biologic impairment is in embryo, proteomics holds the greatest potential in frailty diagnostics.