Evaluation clinique et biologique de la fragilité chez le patient âgé hospitalisé : intérêt de biomarqueurs sanguins dans la prédiction du risque de déclin fonctionnel

Frailty concerns an increasing number of older people and exposes them to an higher risk of negative health outcomes : functional decline, institutionalisation, (re)hospital admission, geriatric syndromes, death). Functional dependence has both personal and public health consequences, e.g. prolonged hospital stay, decreased quality of life and increased health care needs after discharge. However, comprehensive geriatric assessment and acute geriatric interventions have been showed to provide functional benefits and better discharge planning. Inflammation and neuroendocrine dysregulation have been proposed as impaired physiological mechanisms involved in the process of functional decline. Few studies however investigated the potential interest of these biomarkers in hospitalized older patients. The aim of this study was to determine if selected inflammatory and hormonal markers, measured early after admission, could improve the predictive validity of a clinical tool screening for the risk of functional decline following hospitalization of older patients. Main reserch questions developed in this thesis were : 1. Preliminary outcome : How to identify frail older hospitalized patients? 2. Main outcome : do biomarkers contribute to improve the screening of frail hospitalized elderly? 3. secundary outcome : may the dynamics of biomarkers during hospital stay add more useful information in this identification? Proper identification of frailty is indeed a major public health issue to provide adapted care to vulnerable hospitalized elders. Clinical tools predicting functional decline, mainly based on physical or more comprehensive clinical criteria, have shown a moderate discriminative ability and therefore, inclusion of biological factors may improve these performances, as in the estimation of cardiovascular risk (26). Further studies should include larger cohorts, and combine several biomarkers in composite indexes. Another perspective is that persistent changes in inflammatory and endocrine markers may be better predictors of functional decline than baseline measures, as it has been suggested in community-dwelling seniors. In conclusion, screening functional decline in hospitalized older patients may be an estimation of their frailty level. Targeting at-risk patients early after admission is a prior issue, and selected biomarkers, combined with clinical indicators, may improve their identification.(ESP 3) -- UCL, 201