From the Research
The main difference between ordering "total testosterone" versus "testosterone women/children" is in the assay sensitivity and reference ranges used, with the women/children test being more sensitive and specifically calibrated for lower testosterone concentrations typically found in women and children. Total testosterone measures all testosterone in the blood (both bound and free) and is appropriate for adult men with normal to high levels. The testosterone women/children test uses a more sensitive assay specifically calibrated to detect and accurately measure the much lower testosterone concentrations typically found in women and children. Standard total testosterone tests may not be sensitive enough to reliably measure these lower levels, potentially reporting falsely low or undetectable results when testosterone is actually present in the clinically significant range for these populations. When evaluating women for conditions like PCOS, hirsutism, or virilization, or when assessing children for precocious puberty or growth disorders, the women/children assay should be ordered to ensure accurate results, as supported by the study 1 which developed a gas chromatography-tandem mass spectrometry method for determination of androstenedione, dihydrotestosterone, testosterone, estrone, and estradiol in children. The appropriate test selection ensures proper clinical interpretation since reference ranges differ significantly between adult males (300-1000 ng/dL) versus women (15-70 ng/dL) and children (typically <20 ng/dL, varying by age and sex), and the use of a sensitive and specific method like liquid chromatography-tandem mass spectrometry is recommended for accurate measurement of total and free testosterone levels, as stated in the study 2. Some key points to consider when ordering these tests include:
- The assay sensitivity and reference ranges used
- The specific population being tested (adult men, women, or children)
- The clinical condition being evaluated (e.g. PCOS, hirsutism, virilization, precocious puberty, or growth disorders)
- The use of a sensitive and specific method like liquid chromatography-tandem mass spectrometry for accurate measurement of total and free testosterone levels. It is also important to note that the study 3 developed a sensitive and specific stable-isotope dilution liquid chromatography-tandem mass spectrometric method for serum testosterone at the concentrations encountered in women and children, which can be used as a reference for accurate measurement of testosterone levels in these populations. In summary, the choice between ordering "total testosterone" and "testosterone women/children" should be based on the specific clinical context and the need for accurate measurement of testosterone levels in the relevant population, and the use of a sensitive and specific method like liquid chromatography-tandem mass spectrometry is recommended, as supported by the studies 2, 1, and 3.