Identification of Frailty Predictors of Adverse Health Outcomes in Community-dwelling Individuals Aged 50 and Over

Introduction. Although ageing is a general phenomenon, a great inter individual variability on the quality of ageing can be observed. This substantial heterogeneity may be partly explained by extrinsic factors such as lifestyle, habits, physical activity, diet, which may play an important role in the age-associated declines. The concept of frailty was introduced to account for variability in the aging process. This clinical and biological syndrome reflects a decrease in the physiological reserve, and leads to an insidious, precarious equilibrium that can break down during a stressful life event. In older adults, frailty is known to be associated with an increased risk of adverse outcomes, such as falls, fractures, unplanned hospitalizations, and death. Several frailty domains may only be slightly altered, so that early-stage frailty is not necessarily clinically visible. The most commonly used operational definitions of frailty are based on two different conceptual frameworks. Fried's rules-based criteria correspond to a physical phenotype, whereas the "Rockwood accumulative model" defines frailty as the accumulation of multiple deficits. These tools were built for individuals aged 65 and over. However, frailty can also be found in younger adults. Although the early detection of frailty is potentially important (since the condition might be reversible in its early stages), frailty has not been extensively investigated among middle-aged individuals. Indeed, most of the literature studies have focused on older adults or on a small number of frailty parameters the investigators hypothesized that the factors determining the main ageing-related adverse events are already present in middle age. The main objectives of the SUCCEED cohort are therefore to 1/investigate the prevalence of frailty parameters in community-dwelling individuals aged 50 and over, 2/ assess the parameters' prognostic value for future adverse health events, 3/ investigate frailty classifications in