Exploring the association between subjective cognitive decline and frailty: the Hellenic Longitudinal Investigation of Aging and Diet Study (HELIAD)

Background: Subjective cognitive decline (SCD) refers to self-evaluations of impairment in cognitive functions in the absence of objective deficits. Frailty is a multidimensional syndrome that results in increased vulnerability. Both terms are associated with cognitive decline and increased incidence of dementia. The aim of this study was to explore potential associations between SCD and frailty in elderly individuals. Methods: In this cross-sectional study, we included 1454 participants aged 65 and older from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD) study. Individuals with a diagnosis of dementia, mild cognitive impairment, severe anxiety or depression were excluded. SCD were assessed with eighteen questions categorized into cognitive domains. Frailty was assessed according to the Fried definition, the Frailty Index (FI) and the Tilburg Frailty Indicator (TFI). Logistic regression analysis was used to investigate the association. Results: Lower educational level, female sex and low socioeconomic status were found to be associated with frailty and more SCD complaints. Having two or more types of SCD complaints was significantly associated with frailty according to all frailty definitions. All types of SCD complaints were significantly associated with the FI and the TFI. In addition, SCD complaints concerning problems requiring mathematical reasoning had the strongest association with frailty. Conclusion: We found that SCD complaints may be a valid indicator of frailty in cognitively unimpaired older people. We believe that SCD may provide a crucial proactive assessment to detect frailty and to implement programs that will help maintain good health and quality of life during aging.