Cross-sectional and longitudinal associations between physical activity and intrinsic capacity in healthy older adults from the MAPT study

Abstract

Background

The construct of intrinsic capacity (IC) has been recently developed with the aim of assessing and monitoring life-long individuals’ functional trajectories. Physical activity (PA) is recognized for its benefits on health but its associations with IC remain less investigated. We explored the cross-sectional and longitudinal associations of PA with IC in non-demented older adults.

Methods

Eight hundred and thirty-seven males and females aged 70 years and over, were included in the present work. IC and its domains (mobility, vitality, cognition, psychology and sensory) were assessed over 2 years and converted to a 0–100 scale. Participants were categorized into 5 PA groups (0–29; 30–499; 500–999; 1000–1999; and 2000+ MET-min/week) using questionnaires. The associations between PA and IC variables (all reflected and square-root-transformed) observed over 2 years were examined using mixed-effect linear regressions.

Findings

Over the 2-year follow-up, ordinal PA was associated with higher scores in IC (B = -0.066, SE = 0.015, p < .001) In addition, compared to the inactive group, most of the active groups had a slower decline in IC (B_{30–499 MET-min/week} = -0.196, SE = 0.078; B_{500–999 MET-min/week} = -0.208, SE = 0.076; B_{1000–1999 MET-min/week} = -0.165, SE = 0.073; B_{2000+MET-min/week} = -0.187, SE = 0.074; all p < .05). Subdomain analyses revealed that these associations were driven by mobility, vitality and psychological domain.

Interpretation

This study suggests that PA may help preventing IC decline, especially mobility, vitality, and psychology in older adults.