Is there an association between serum prostate-specific antigen values and serum testosterone levels in healthy men?

To evaluate the relationship between levels of total testosterone and total prostate-specific antigen (PSA) in healthy men with PSA<4 ng/mL.

The study comprised 179 men with a mean age of 59.19±12 years who visited Osmaniye State Hospital, Osmaniye, Turkey, between January 2006 and January 2007 for a routine checkup. The patients were divided into two subgroups: patients with PSA<2.5 mg/ml (group I, n=160 patients) and patients with PSA of 2.5 to 4 ng/mL (group II, n=19 patients). The relationship between PSA and testosterone levels was investigated in both groups and in patients aged <60 years. The mean testosterone level was calculated for patients aged <50 years and was compared with the mean value of patients aged ≥50 years.

In all patients, the mean values for serum PSA and total testosterone were 1.27±0.88 ng/mL and 404.04±158.86 ng/mL, respectively. No correlation was detected between serum PSA and testosterone levels in either subgroup (group I, r=0.072, p=0.363; group II, r=0.031, p=0.900) or in patients aged <60 years (r=0.032, p=0.72). The mean values of testosterone in patients aged ≥50 years and in patients aged <50 years were 417.01±163.35 and 344.16±120.21 ng/dL, respectively (p=0.02).

No impact of testosterone was found on the PSA level in healthy men with PSA <4 ng/mL. Therefore, a high serum testosterone level may not mandate adjustment of PSA values. This serum sex hormone showed a significant increment after the age of 50 years. Further studies including a larger number of patients should be carried out to confirm these findings.