Feeling Younger as an Indicator of Better Overall Intrinsic Capacities in the INSPIRE-T Cohort

Existing literature indicates that subjective age-the age an individual feels or perceives themselves to be-is associated with various health outcomes. However, its relationship with global indicators such as intrinsic capacity remains inadequately explored. The primary objective of this study was to investigate the association between subjective age and intrinsic capacities, which encompass mobility, cognition, hearing, vision, mood, and nutrition.

A cross-sectional analysis was conducted at baseline, followed by a longitudinal analysis over 8 months, based on the INSPIRE-T project launched in 2019 at a single center in Toulouse, France. The study included individuals aged 50 and above, with 744 participants at baseline, decreasing to 557 for the longitudinal analysis. Bivariate and multivariate logistic regressions were performed for each component of intrinsic capacity and a linear regression was conducted on a global score for impaired intrinsic capacities (0-6).

Participants had a mean age of 70.9 years, and 457 (61%) were women. Compared to feeling one's age, feeling younger was significantly associated with less impairment in the intrinsic capacity global score both cross-sectionally (-0.23 [-0.39 to -0.07]) and at 8 months (-0.18 [-0.35 to -0.01]). Feeling older exhibited a non-significant opposite trend. Analysis of each intrinsic capacity domain revealed associations between subjective age and mood, mobility, and hearing.

This study demonstrates that feeling younger than one's age is associated with better overall intrinsic capacities at baseline and lesser decline over the monitoring period. Routine assessment of subjective age could help to identify individuals who may benefit from prevention strategies and could promote patient-centered care by providing deeper insights into individuals' perceptions of aging.

The INSPIRE-T study has been registered on the site http://clinicaltrials.gov (ID NCT04224038) on October 15, 2019.