[Value of the serum free testosterone level in detecting erectile dysfunction]

Area of Science:

• Andrology
• Endocrinology
• Urology

Background:

• Erectile dysfunction (ED) is a common condition often linked to androgen deficiency.
• Accurate diagnosis of androgen deficiency is crucial for effective ED management.
• Existing markers for assessing testosterone levels may have limitations in diagnosing ED.

Purpose of the Study:

• To evaluate the diagnostic utility of serum calculated free testosterone (cFT), testosterone secretion index (TSI), and free testosterone index (FTI) in identifying androgen deficiency in men with ED.
• To compare the diagnostic accuracy of cFT, TSI, and FTI against total testosterone (TT) as a gold standard.

Main Methods:

• A study involving 150 men with ED and 35 healthy controls (aged 20-40).
• Assessment included medical history, International Index of Erectile Function (IIEF-5) questionnaire, nocturnal penile tumescence (NPT) test, and measurement of serum hormones (TT, LH, SHBG, ALB, cFT, bio-T, TSI, FTI).
• Diagnostic accuracy (coincidence, missed diagnosis, misdiagnosis rates) was calculated using established critical values for cFT, TSI, FTI, and TT.

Main Results:

• Serum cFT demonstrated the highest diagnostic coincidence rate (90.8%) for androgen deficiency in ED patients compared to TSI (85.8%) and FTI (80.8%).
• cFT also showed the lowest missed diagnosis rate (4.0%) and a favorable misdiagnosis rate (10.5%).
• Serum cFT, bio-available testosterone (Bio-T), TSI, and FTI levels decreased with age in ED patients (20-40 years), but TT levels did not show significant age-related differences.

Conclusions:

• Serum calculated free testosterone (cFT) is a more valuable diagnostic marker for androgen deficiency in young men (20-40) with ED than TT, TSI, and FTI.
• These findings support the use of cFT for improved diagnosis and management of ED associated with low testosterone.