PSA level saturates with increasing frequency of sexual activity & bicycling while MRI remains constant. Soeletormos G et al., "Biological variation of total prostate-specific antigen: A survey of published estimates and consequences for In a separate paper an attempt is made to factor out sexual activity in order to isolate the effect.
Before having a PSA test to test for prostate cancer, men shouldn't have ejaculated during the previous 48 hours. Semen released during sexual activity can cause prostate-specific antigen (PSA) levels to rise temporarily, which may affect the test results. For the same reason, before having a PSA.
And a new study sheds surprising light on a previously unsuspected reason for PSA variability. Rapid changes Short-term variations in the PSA are well-known. Inflammation of the prostate (prostatitis) and urinary tract infections boost the PSA rapidly, often to very high levels. The same is true for medical manipulations that affect the gland.
The percent free serum PSA was calculated as the ratio of serum free PSA to total PSA multiplied by 100. After discussing this situation with the patient, we were informed that he had sexual activity and ejaculation in less than 24 hours before the first and before the last serum PSA measurements (being 6 and 7 ng/ml respectively).