Midlife aging and performance study (MAPS): evaluating biological aging through a physical capacity battery.

Aging is a risk factor for the development of chronic diseases; however, it is heterogeneous. Measuring aging in midlife, commonly done using laboratory markers and statistical methods for estimation of biological age (BA), cannot directly inform behavioral intervention goals aiming to promote healthier aging. The Midlife Aging and Performance Study (MAPS) examined the association between an extended, inclusive assessment of physical capacity (PC), as a behavioral marker of aging, and BA, estimated using the Klemera-Doubal method from 11 laboratory and physiological biomarkers, in 112 individuals aged 42-46 (47% women). PC was comprehensively measured by a battery covering five domains: muscle strength, endurance, balance, agility and flexibility. Better performance in strength, endurance, balance, and flexibility domains was correlated with younger BA (Pearson's r 0.33-0.49, p < 0.001). A lower composite PC score based on all five domains was significantly associated with an accelerated aging state in which BA was greater than chronological age. In a logistic regression, a composite PC score had an odds ratio of 0.40 (95% CI 0.25-0.64), demonstrating each incremental rise in PC corresponds with a 60% odds reduction of being in an accelerated aging state. The proposed PC battery could be used as a functional behavioral assessment for aging state, relevant for population wide risk-screening assessments, communicating intervention goals, and as a means to evaluate temporal changes in health, independent of laboratory tests.