title: 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.
  
  
  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.
authors.affiliation: Vanderbilt University, Department of Medicine, Division of Cardiovascular Medicine, Nashville, Tennessee, USA.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Goffaux
authors.forename: Gottlieb C
authors.initials: GC
authors.lastname: Friesinger
authors.forename: Warren
authors.initials: W
authors.lastname: Lambert
authors.forename: Laurie W
authors.initials: LW
authors.lastname: Shroyer
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Moritz
authors.forename: Martin
authors.initials: M
authors.lastname: McCarthy
authors.forename: William G
authors.initials: WG
authors.lastname: Henderson
authors.forename: Karl E
authors.initials: KE
authors.lastname: Hammermeister
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology; D015331:Cohort Studies; D005260:Female; D016330:Frail Elderly; D015577:Geriatric Assessment / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D008017:Life Expectancy; D008136:Longevity; D008297:Male; D010865:Pilot Projects; D011788:Quality of Life; D012044:Regression Analysis