Body composition in 65+ European population: a focus on inflammatory and metabolic markers in healthy and frail

Objectives: The aims of this PhD work were: 1. provide a profile of Body Composition (BC) in healthy elderly from five European countries and investigate country- and sex-related differences; 2. explore the relationship between BC markers for adipose and lean tissue and bone mass, and inflammatory and adipose-related markers in healthy elderly Europeans; 3. detect differences of BC and health markers that characterize pre-frail or frail individuals trying to define a “frailty signature”. Methods: Data from whole-body dual-energy X-ray absorptiometry (DXA) scan, markers of inflammation as well as clinical dataset were available for 1,121 healthy (65-79 years) non-frail and pre-frail women and men from five European countries participating to the “NU-AGE" EU project (NCT01754012) and 23 frail women and men participating to the “ProAGE” Project (DUND-100373). The presence of frailty was assessed using the standardized phenotype scale proposed by Fried et al. Advanced statistical methods such as hierarchical cluster analysis were applied in order to answer the above-mentioned research questions. Results: BC characteristics were different in elderly women and men, and more favorable BC markers were associated with a better adipose-related inflammatory profile, with the exception of skeletal muscle mass index. Moreover, five BC profiles in women and six in men have been identified by a hierarchical cluster analysis based on BC parameters. Furthermore, frail subjects have significantly higher fat mass and lower lean mass markers compared with non-frail and pre-frail subjects and the amount of subcutaneous adipose tissue (SAT) seems to be a valid predictor of frailty in elderly female. Conclusions: BC parameters measured by DXA are different among healthy male and female elderly across Europe and also among frail and non-frail subjects and are specifically associated with health and inflammatory markers. BC represents a key factor in the aging process and in the prevention of age-related pathologies.