Use of calculated free testosterone in men: advantages and limitations.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic methodology or primary empirical data
PubMed 39445719 · doi:10.1097/MED.0000000000000891
What was done
This narrative review summarizes the clinical utility, indications, and limitations of calculated free testosterone (cFT) as a second-line diagnostic tool for male hypogonadism, addressing the practical use of calculated proxies versus equilibrium dialysis.
What was found
The abstract reports no numbers or statistical metrics. It describes how age and obesity alter total testosterone and SHBG levels, notes that low free testosterone correlates with androgen deficiency even with normal total testosterone, and highlights that common free testosterone calculators lack standardization.
Why it matters
Calculated free testosterone provides a practical second-line assessment to prevent misdiagnosis and overtreatment in men with altered SHBG levels, though clinicians must account for calculator variability.
Limits
As a narrative review, the paper presents no original data, quantitative performance metrics, or study sample sizes. It identifies substantial inherent limits in clinical practice, particularly the lack of standardization across different free testosterone calculators.
Cited by
- supports Sex hormone-binding globulin (SHBG) binds approximately 60% of total testosterone, albumin binds about 38%, and free testosterone makes up roughly 2% to 3%.