Effects of ejaculation on serum prostate-specific antigen levels.

OBJECTIVE

The aim of this study is to evaluate the effect of ejaculation on serum total, free and complex prostate-specific antigen (PSA) levels and their effect on biopsy decisions.

MATERIAL AND METHODS

Our study includes 47 men older than 45 years with symptomatic benign prostatic hyperplasia (BPH). Patients' PSA levels were under 2.5 ng/mL, and there were no known conditions to preclude ejaculation. Eight patients with similar demographic, and clinical characteristics were chosen as a control group. With three days of sexual abstinence, blood samples were drawn for the measurement of baseline PSA levels, and then the patients were told to ejaculate. One, 5, 24 and 72 hours after ejaculation, serum total, free and complexed PSA levels were measured. Serum PSA sampling was performed at the same intervals in the control group without ejaculation.

RESULTS

The mean age of the patients was 59.13±1.38 years in the study group, and 63.75±3.13 years in the control group. The mean international prostate symptom scores (IPSS) were 11.78±1.12 and 11.63±3.32 in the study, and the control groups, respectively. The mean baseline total, free, and complexed PSA values were 1.07±0.09, 0.31±0.03, and 0.71±0.08 ng/mL, respectively. In the study group, total PSA value was found to be 1.29±0.12 ng/mL (p=0.008) at first hour after ejaculation, and this change was statistically significant when compared with baseline values. Mean total PSA level rose up to 1.28±0.13 ng/mL (p=0.05) by the 5(th) hour after ejaculation, but this change was not statistically significant relative to the baseline values. Mean free PSA level rose after the first hour postejaculation to 0.37±0.04 ng/mL (p=0.01) and after the fifth hour postejaculation to 0.37±0.04 ng/mL (p=0.002), and these changes were statistically significant relative to the baseline values. There were no statistically significant changes at the other sampled times as for the total, free or complexed PSA serum levels. When all three values were considered individually, in only 2.12% of the patients, biopsy decisions could be affected by the elevation in PSA levels.

CONCLUSION

When the PSA value is borderline with respect to biopsy decisions, the effect of ejaculation on serum PSA levels may be clinically important. In these patients, ejaculation must be questioned, and repeated. PSA levels should be evaluated 24 hours after ejaculation. There were no statistically significant changes in the levels of complex PSA values. Further studies are needed to clarify the relationship between complexed PSA and ejaculation.