It’s time to reconsider early-morning testosterone tests
Guidelines recommend collecting an early-morning sample to compensate for the natural diurnal variation in testosterone levels. But for men 45 and older, this is unnecessary.
Up to 30% of men who have an early-morning testosterone level that is low may have a normal result when testing is repeated.2,5 Therefore, for all men who have low testosterone level test results, draw a repeat total testosterone level before 9 am to confirm the diagnosis. Also, this study did not evaluate the course of testosterone levels throughout the later afternoon and evening, and it remains unclear whether levels can be drawn even later in the day.
CHALLENGES TO IMPLEMENTATION: Your lab's policies might require early-morning draws
There will probably be few barriers to implementing this change, unless local laboratory policies are inflexible regarding the timing of testosterone draws.
ACKNOWLEDGEMENT
The PURLs Surveillance System was supported in part by Grant Number UL1RR024999 from the National Center For Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Research Resources or the National Institutes of Health.
