Original Article
Biological Age - A Concept Whose Time Has Come: A Preliminary Study
Abstract
Objective: Chronology poorly predicts biological age (BA) or physiologic reserve (PR). An objective approach to the heterogeneity of aging would greatly help clinical decision making in the elderly.
Materials And Methods: The first pilot study evaluated 130 “healthy” volunteers, ages 70 to 95 years. A summary BA/PR index was developed, using measures of endurance, strength, flexibility, balance, cognition, depression, comorbidity, and exercise. The second study applied the BA/PR concept to prediction of death after a first elective coronary artery bypass graft, using a Veterans Administration database.
Results: The BA/PR index was a better predictor of 3-year functional outcomes and death than was chronological age. In the coronary artery bypass graft study, the inclusion of BA/PR variables significantly improved prediction of 6-month and long-term death for Veterans Administration patients.
Conclusions: The usefulness of a biological age (BA/PR) approach in predicting outcomes in the elderly was supported. Needed research should develop tools for routine “tracking” of the aging process.
Key Points
* Major heterogeneity in biological age/physiological reserve (BA/PR) was present in high functioning “healthy” individuals, age 70 years or older.
* Simple measures, and especially timed tests (eg, Trails B, 6-minute walk, standing on one foot), can be used to characterize this heterogeneity.
* BA/PR measures were more predictive of adverse outcomes than chronological age in pilot studies involving older samples of (a) 128 independent-living “healthy” individuals and (b) 606 veterans undergoing coronary artery bypass graft.
* Further research is needed to determine the most predictive BA/PR measures and to extend the concept to broader groups.
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