title: Development and application of biological age prediction models with physical fitness and physiological components in Korean adults.
abstract: BACKGROUND
  Several biological age (BA) prediction models have been suggested with a variety of biomarkers. Valid models should be able to measure BA in a relatively short time period and predict subsequent physiological capability. Physiological and physical fitness variables have been shown to be distinctive markers for predicting BA and morbidity. The practical and noninvasive nature of such variables makes them useful as clinical assessment tools in estimating BA for in-depth diagnosis and corresponding intervention.
  
  
  OBJECTIVE
  To identify, develop and evaluate biomarkers and BA prediction models and validate their clinical usefulness for the practical diagnosis of functional aging.
  
  
  METHODS
  Fourteen variables were measured in 3,112 male and 1,233 female participants aged 30 and older between the years 2004 and 2007. Through a series of parsimonious stepwise elimination processes, two sets of 8 gender-specific variables were selected as candidate biomarkers for 1,604 men and 760 women. Principal component analysis, linear regression analysis and adjustment methods were further applied to obtain two sets of true BA (TBA) prediction models. The TBA models were examined for validity by comparing TBA to the corresponding chronological age (CA) with clinical risk factors.
  
  
  RESULTS
  TBA prediction models with r(2) values of 0.638 and 0.672 were developed, each unique to men and women, respectively. The overall mean TBA and CA of the participants were 53.9 and 51.8 years, respectively, with a marginal difference of -2.1 and -1.3 years. The regression slopes or rates of TBA as a function of CA were 1.00 and 1.28 for men and women with r values of 0.799 and 0.820 (p < 0.001), respectively. In comparing TBA to CA rates between healthy and clinical risk groups, both sarcopenic and obese groups showed significant increases in TBA.
  
  
  CONCLUSIONS
  The selected biomarkers encompass various complex physiopathological factors related to intrinsic and extrinsic physiological and functional aging. The BA prediction models based on the selected biomarkers could be practical in assessing BA for Korean adults.
authors.affiliation: Department of Medical Science, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Haemi
authors.initials: H
authors.lastname: Jee
authors.forename: Byeong Hwan
authors.initials: BH
authors.lastname: Jeon
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Kim
authors.forename: Hong-Kyu
authors.initials: HK
authors.lastname: Kim
authors.forename: Jaeone
authors.initials: J
authors.lastname: Choe
authors.forename: Jaehyun
authors.initials: J
authors.lastname: Park
authors.forename: Youngsoo
authors.initials: Y
authors.lastname: Jin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000886:Anthropometry; D044466:Asian People; D015415:Biomarkers; D001794:Blood Pressure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010809:Physical Fitness / Q000502:physiology*; D012044:Regression Analysis; D056910:Republic of Korea; D012129:Respiratory Function Tests; D012307:Risk Factors
chemical_list: D015415:Biomarkers