title: [Relationship of age over 50 years and serum prostate specific antigen in men of Beijing multicentre communities].
abstract: OBJECTIVE
  To investigate the relationship of prostate-specific antigen (PSA) with age in men older than 50 years in Beijing.
  
  
  METHODS
  A cross-sectional study was performed in men aged over 50 years at communities in Beijing, and serum total PSA (T-PSA) and free PSA (F-PSA) levels were assayed. The relationship between age and PSA was analyzed with simple linear regression.
  
  
  RESULTS
  A total of 1 027 subjects were enrolled. Serum T-PSA and F-PSA levels were positively correlated with age (r=0.208,P<0.001; r=0.230, P<0.001), whereas F/T ratio wasn't correlated with age (r=0.055, P>0.079). The upper limit (95% CI) for serum PSA: 1.55 μg/L for 50-59 years, 2.08 μg/L for 60-69 years, 2.40 μg/L for 70-79 years, 3.52 μg/L for ≥80 years.
  
  
  CONCLUSIONS
  Of the men aged over 50 years in Beijing, there is a positive correlation between serum T-PSA, F-PSA and age; whereas F/T ratio isn't correlated with age.
authors.affiliation: Department of Urology, Peking University First Hospital, Beijing 100034, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Xiang-hua
authors.initials: XH
authors.lastname: Zhang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhang
authors.forename: Shu-qing
authors.initials: SQ
authors.lastname: Li
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000517:prevention & control; D012494:Sampling Studies
chemical_list: D017430:Prostate-Specific Antigen