[A preliminary study of PSA level in 646 healthy men in Beijing].

OBJECTIVE: To evaluate the levels of total PSA (tPSA), free PSA (fPSA) and fPSA/t PSA ratio in healthy men in Beijing and analyze the relationship between age and PSA indexes. METHODS: Serum tPSA and fPSA were measured by electrochemi luminescence immune assay (ECLIA) and fPSA/t PSA ratio was calculated in 646 healthy men of 20 approximately 90 years old. The relationship between age and PSA indexes was analyzed by simple linear regression. RESULTS: In 20 approximately 30 years old cases, t PSA was 0.9 ng/ml +/- 0.6 ng/ml, fPSA was 0.27 ng/ml +/- 0.19 ng/ml and fPSA/t PSA ratio was 0.36 +/- 0.20. In 31 approximately 40 years old group, tPSA was 0.8 ng/ml +/- 0.6 ng/ml, fPSA was 0.22 ng/ml +/- 0.15 ng/ml and fPSA/tPSA ratio was 0.34 +/- 0.25. In 41 approximately 50 years old group, tPSA was 0.8 ng/ml +/- 0.6 ng/ml, fPSA was 0.21 ng/ml +/- 0. 14 ng/ml and fPSA/tPSA ratio was 0.34 +/- 0.23. In 51 approximately 60 years old group, tPSA was 1.0 ng/ml +/- 0.6 ng/ml, fPSA was 0.25 ng/ml +/- 0.15 ng/ml and fPSA/tPSA ratio was 0.31 +/- 0.19. In 61 approximately 70 years old group, tPSA was 1.0 ng/ml +/- 0. 7 ng/ml, fPSA was 0.25 ng/ml +/- 0.18 ng/ml and fPSA/tPSA ratio was 0.27 +/- 0.18. In 71 approximately 80 years old group, tPSA was 1.1 ng/ml +/- 0.7 ng/ml, fPSA was 0.31 ng/ml +/- 0.23 ng/ml and fPSA/tPSA ratio was 0.29 +/- 0.14. In 81 approximately 90 years old group, tPSA was 1.3 ng/ml +/- 1.1 ng/ml, fPSA was 0.4 ng/ml +/- 0.4 ng/ml and fPSA/tPSA ratio was 0.36 +/- 0.17. By univariate analysis, no correlation was found between serum PSA indexes and ages. CONCLUSIONS: The reference ranges of all PSA indexes in Chinese men may be lower than in that western men. There is no correlation between serum PSA indexes and ages. The reference range of 0 to 4 ng/ml used in the West may not be applicable to Chinese patients.