title: Construction of an integral formula of biological age for a healthy Chinese population using principle component analysis.
abstract: BACKGROUND
  Whereas chronological age (CA) cannot distinguish functional differences among individuals of the same age, the biological age (BA) may be used to reflect the functional state of the body. The purpose of this study was to construct an integral formula of the BA, by using principle component analysis (PCA).
  
  
  METHODS
  The vital organ function of 505 healthy individuals of Han origin (age 35-91 years) was examined. A total of 114 indicators of cardiovascular, pulmonary, and brain functions, and clinical, inflammatory, genetic, psychological, and life habit factors were assessed as candidate indicators of aging. Candidate indicators were submitted with CA to correlation and redundancy analyses. The PCA method was used to build an integral formula of the BA for the population.
  
  
  RESULTS
  Seven biomarkers were selected in accordance with a certain load standard. These biomarkers included the trail making test (TMT), pulse pressure (PP), mitral valve annulus ventricular septum of the peak velocity of early filling (MVES), minimum carotid artery intimal-medial thickness (IMTmin), maximum internal diameter of the carotid artery (Dmax), maximal midexpiratory flow rate 75/25 (MMEF75/25), and Cystatin C (CysC). The formula for the BA was: BA = 0.0685 (TMT) + 0.267 (PP) - 1.375 (MVES) + 22.443 (IMTmin) + 2.962 (Dmax) - 2.332 (MMEF75/25) + 16.104 (CysC) + 0.137 (CA) + 0.492.
  
  
  CONCLUSIONS
  Several genetic and lifestyle indicators were considered as candidate markers of aging. However, ultimately, only markers reflecting the function of the vital organs were included in the BA formula. This study represents a useful attempt to employ multiple indicators to build a comprehensive BA evaluation formula of aging populations.
authors: Xiang-Mei Chen, Department of Nephrology, Kidney Institute of Chinese PLA, Chinese PLA General Hospital, State Key Laboratory of Kidney Diseases, Beijing, 100853, People's Republic of China, Email: xmchen301@126.com, Phone: 86-010-66937463, Fax: 86-010-68130297.
authors: W-G
authors: WG
authors: Zhang
authors: X-J
authors: XJ
authors: Bai
authors: X-F
authors: XF
authors: Sun
authors: G-Y
authors: GY
authors: Cai
authors: X-Y
authors: XY
authors: Bai
authors: S-Y
authors: SY
authors: Zhu
authors: M
authors: M
authors: Zhang
authors: X-M
authors: XM
authors: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D044466:Asian People; D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000378:metabolism; D002319:Cardiovascular System / Q000378:metabolism; D017536:Carotid Artery, Common / Q000378:metabolism; D059168:Carotid Intima-Media Thickness; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008019:Life Style; D016014:Linear Models; D008168:Lung / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D025341:Principal Component Analysis; D014145:Trail Making Test; D017539:Tunica Intima