From the Research
Prostate-Specific Antigen (PSA) levels are typically highest in the morning hours, specifically between 9:00 and 11:00 am, and decrease in the afternoon. This diurnal variation in PSA levels occurs due to the natural circadian rhythm of hormone production in the body, as suggested by a study published in 2019 1. The study found that 87.5% of patients had a decrease in PSA levels when measured in the afternoon compared to the morning, with a statistically significant difference between the morning and afternoon PSA levels. Key points to consider include:
- The diurnal variation in PSA levels can affect clinical interpretation, with afternoon measurements potentially being 10-30% lower than morning measurements in the same individual.
- For consistency in PSA monitoring, patients should try to schedule their blood draws at approximately the same time of day for each test, preferably in the morning, to ensure the most accurate comparison of results across different time points.
- The natural fluctuation in PSA levels is important to consider when monitoring PSA levels over time, especially for men undergoing active surveillance for prostate conditions. It is essential to prioritize the most recent and highest quality study, which in this case is the 2019 study published in The Prostate 1, to guide clinical decision-making regarding PSA testing and interpretation.