Effect of calendar age on physical performance: A comparison of standard clinical measures with instrumented measures in middle-aged to older adults

Background: Decline in physical performance is highly prevalent during aging. Identification of sensitive markers of age-related changes in physical performance is important for early detection, development of therapeutic strategies and insight into underlying mechanisms. We studied the association of calendar age and familial longevity with standard clinical and instrumented measures of physical performance in a cohort of healthy middle-aged to older adults.

Methods: Cross-sectional analysis within the Leiden Longevity Study consisting of offspring of nonagenarian siblings and their partners (n=300, mean age (SD) 65.3 (6.7) years). Standard clinical measures were 25-meter walking speed and total duration of the chair stand test (CST). Instrumented measures were determined using a body fixed sensor. Dependence of physical performance on calendar age and familial longevity (offspring versus partner status) was analyzed using linear and logistic regression, respectively, adjusted for gender and height.

Results: Higher calendar age was associated with slower walking speed and longer duration of the CST (standardized β (95% CI) -.024 (-.042; -.006) and .035 (.014;.056), respectively). Instrumented measures showed similar effect sizes with strongest associations for gait stability and symmetry in mediolateral direction and for the extension and flexion phase of sit-to-stand and stand-to-sit transfers, respectively. No differences were observed between offspring of nonagenarian siblings and their partners.

Conclusions: Standard clinical and instrumented measures of physical performance are associated with similar effect size to age-related changes in physical performance observable from middle age. The potential added value of instrumented measures for understanding underlying mechanisms requires further attention.